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Home » Modeling » EMF "Technology" (Ecore Tools, EMFatic, etc)  » [CDO] reading/writting throughput performances
[CDO] reading/writting throughput performances [message #123583] Thu, 29 May 2008 10:22 Go to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 Features)

The test is a "quick and dirty" one so please do not take these figures too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.


* First case : building a small model (10000 elements) with the simple MM,
only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.

browsing the just commited elements opening a new transaction and getting a
new Resource instance, I get around 30 000 objets/sec rate just iterating
thanks to Resource.getAllContents().

* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely (I
did not measured it exactly as it was launched during a night, but it seems
I got around 100 objects/sec rate in writting as I was writting every 700
objects.


Once the model is built the derby database is 222 MB (which - I heard - is
not so big for derby).

Retrieving the distant resource and calling eAllContents() on it, I get a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !

This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


<repository name="repo1">
<property name="overrideUUID"
value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
<property name="supportingAudits" value="true"/>
<property name="verifyingRevisions" value="false"/>
<property name="currentLRUCapacity" value="10000"/>
<property name="revisedLRUCapacity" value="100"/>

<store type="db">
<!-- type: horizontal | vertical | <any user-contributed type> -->
<mappingStrategy type="horizontal">
<!-- ONE_TABLE_PER_REFERENCE | ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
<property name="toManyReferences" value="ONE_TABLE_PER_REFERENCE"/>

<!-- LIKE_ATTRIBUTES | LIKE_TO_MANY_REFERENCES -->
<property name="toOneReferences" value="LIKE_ATTRIBUTES"/>

<!-- MODEL | STRATEGY -->
<property name="mappingPrecedence" value="MODEL"/>
</mappingStrategy>

<dbAdapter name="derby-embedded"/>
<dataSource class="org.apache.derby.jdbc.EmbeddedDataSource"
databaseName="/tmp/cdodb1"
createDatabase="create"/>

</store>
</repository>




What do you think about that ? What throughput do you think I should
expect ? What are the main reasons fur such figures ?

I can provide you the "stupid" test case and even profile the code more
closely if you want.


Cédric


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #123598 is a reply to message #123583] Thu, 29 May 2008 11:27 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------090102080203020800020703
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Hi Cédric,

That sounds interesting!
Comments inline...


Cédric Brun schrieb:
> Hi Eike,
>
> I've been messing around CDO lately and I hacked a few ugly unit-tests
> measuring read/write throughput when I use CDO (RC2).
>
> I'm using an embeded-derby database, two different metamodels (complex one -
> 250 EClassifiers/300 features and a simple one - 1 Classifier/3 Features)
>
> The test is a "quick and dirty" one so please do not take these figures too
> seriously, I would just like to have your input about the "order of
> magnitude" I should expect or settings affecting seriously these
> performances. I tried both JVM and TCP acceptor but the performances are
> quite similar though JVM is a bit faster.
>
Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?

>
> * First case : building a small model (10000 elements) with the simple MM,
> only adding instances in an empty database :
> commiting change on every add I get a 2 objects per second rate.
> commiting changes every 10 adds - I get a 30 objects per second rate.
>
Seems to be consistent with the fact that only for commits there is
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger transactions.

> browsing the just commited elements opening a new transaction and getting a
> new Resource instance, I get around 30 000 objets/sec rate just iterating
> thanks to Resource.getAllContents().
>
Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) their
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.
But the DBStore (which you used) is not that optimized.

> * Second case : I built a big model in the database using the complex
> metamodel. It contains 700 000 elements. The creation went pretty nicely (I
> did not measured it exactly as it was launched during a night, but it seems
> I got around 100 objects/sec rate in writting as I was writting every 700
> objects.
>
Sounds not too bad.

>
> Once the model is built the derby database is 222 MB (which - I heard - is
> not so big for derby).
>
Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write simple
SQL statements).

> Retrieving the distant resource and calling eAllContents() on it, I get a 50
> Objects/sec rate at best, which mean my eAllContents() call would take 4
> hours !
>
Currently I'm not sure what exactly eAllContents() does do (iteration
order and so).
There are several CDO features that can have a major impact on load rates!

- Collections (xrefs and containment) can be loaded lazily. I don't mean
the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).
|*public interface *CDOSession *extends *CDOProtocolSession, IContainer<CDOView>
{
*public **int *getReferenceChunkSize();

*public **void *setReferenceChunkSize(*int *referenceChunkSize);|


- Loading collection elements (target objects) can be batched (the
current name is even worse)
|*public interface *CDOView *extends *CDOProtocolView, INotifier
{
*public **int *getLoadRevisionCollectionChunkSize();

*public **void *setLoadRevisionCollectionChunkSize(*int *loadRevisionCollectionChunkSize);|



- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.
|*public class *CDOViewImpl *extends *org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView, CDOIDProvider,
Adapter.Internal
{
*public *CDOFeatureAnalyzer getFeatureAnalyzer()
{
*return *featureAnalyzer;
}

*public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
{
*this*.featureAnalyzer = featureAnalyzer == *null *? CDOFeatureAnalyzer.NOOP : featureAnalyzer;
}|


- There's a SmartReadAheadThread (if you're curious, please ask Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts
(by design)
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see
https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
- Maybe others...

Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore.

> This is probably linked to the way the mapping to db is done, here's the
> config I used (came from CDO-server example if I recall correctly).
>
>
> <repository name="repo1">
> <property name="overrideUUID"
> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
> <property name="supportingAudits" value="true"/>
> <property name="verifyingRevisions" value="false"/>
> <property name="currentLRUCapacity" value="10000"/>
>
I guess this one could be larger.

> <property name="revisedLRUCapacity" value="100"/>
>
> <store type="db">
> <!-- type: horizontal | vertical | <any user-contributed type> -->
> <mappingStrategy type="horizontal">
> <!-- ONE_TABLE_PER_REFERENCE | ONE_TABLE_PER_CLASS |
> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
> <property name="toManyReferences" value="ONE_TABLE_PER_REFERENCE"/>
>
> <!-- LIKE_ATTRIBUTES | LIKE_TO_MANY_REFERENCES -->
> <property name="toOneReferences" value="LIKE_ATTRIBUTES"/>
>
> <!-- MODEL | STRATEGY -->
> <property name="mappingPrecedence" value="MODEL"/>
>
This one is obsolete.

> </mappingStrategy>
>
> <dbAdapter name="derby-embedded"/>
> <dataSource class="org.apache.derby.jdbc.EmbeddedDataSource"
> databaseName="/tmp/cdodb1"
> createDatabase="create"/>
>
> </store>
> </repository>
>
>
>
>
> What do you think about that ? What throughput do you think I should
> expect ?
As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with values
from other measures (other setups, properties, etc. or even other
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to grow
slowly ;-)

> What are the main reasons fur such figures ?
>
Hmm, I *suspect* you don't like the figures? I can find no evidence your
assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and end-to-end
throughput.
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).

Cheers
/Eike



--------------090102080203020800020703
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Hi Cédric,<br>
<br>
That sounds interesting!<br>
Comments inline...<br>
<br>
<br>
Cédric Brun schrieb:
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 Features)

The test is a "quick and dirty" one so please do not take these figures too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
</pre>
</blockquote>
Looks like a sign that the NIO socket channels are efficient ,-)<br>
You used localhost for TCP transport I guess?<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">

* First case : building a small model (10000 elements) with the simple MM,
only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
</pre>
</blockquote>
Seems to be consistent with the fact that only for commits there is
remote traffic.<br>
And the backend transaction management is another overhead.<br>
So the impact of the number objects/commit starts with bigger
transactions.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">
browsing the just commited elements opening a new transaction and getting a
new Resource instance, I get around 30 000 objets/sec rate just iterating
thanks to Resource.getAllContents().
</pre>
</blockquote>
Hehe, this is a sign that client side caching works well:<br>
All views and transactions of a single session share (and cache) their
object state.<br>
Otherwise I'd expect much smaller values.<br>
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.<br>
But the DBStore (which you used) is not that optimized.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">
* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely (I
did not measured it exactly as it was launched during a night, but it seems
I got around 100 objects/sec rate in writting as I was writting every 700
objects.
</pre>
</blockquote>
Sounds not too bad.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">

Once the model is built the derby database is 222 MB (which - I heard - is
not so big for derby).
</pre>
</blockquote>
Hmm, I have no extensive experience with Derby.<br>
To be honest, I'm really no database expert (although I can write
simple SQL statements).<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">
Retrieving the distant resource and calling eAllContents() on it, I get a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
</pre>
</blockquote>
Currently I'm not sure what exactly eAllContents() does do (iteration
order and so).<br>
There are several CDO features that can have a major impact on load
rates!<br>
<br>
- Collections (xrefs and containment) can be loaded lazily. I don't
mean the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).<br>
<title></title>
<style type="text/css">
<!--code { font-family: Courier New, Courier; font-size: 10pt; margin: 0px; }-->
</style>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<!-- ======================================================== --><!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = -->
<!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"> <code><font color="#7f0055"><b>public interface </b></font><font
color="#000000">CDOSession </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">CDOProtocolSession, IContainer&lt;CDOView&gt; </font><br>
<font color="#000000">{</font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>int </b></font><font color="#000000">getReferenceChunkSize</font><font
color="#000000">()</font><font color="#000000">;</font><br>
<font color="#ffffff"></font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setReferenceChunkSize</font><font
color="#000000">(</font><font color="#7f0055"><b>int </b></font><font
color="#000000">referenceChunkSize</font><font color="#000000">)</font><font
color="#000000">;</font></code> </td>
<!-- end source code --> </tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = --><br>
<!-- ======================================================== -->
- Loading collection elements (target objects) can be batched (the
current name is even worse)<br>
<title></title>
<style type="text/css">
<!--code { font-family: Courier New, Courier; font-size: 10pt; margin: 0px; }-->
</style>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<!-- ======================================================== -->
<!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = -->
<!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"> <code><font color="#7f0055"><b>public interface </b></font><font
color="#000000">CDOView </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">CDOProtocolView, INotifier</font><br>
<font color="#000000">{</font><br>
<font color="#ffffff"></font><font color="#ffffff">  </font><font
color="#7f0055"><b>public </b></font><font color="#7f0055"><b>int </b></font><font
color="#000000">getLoadRevisionCollectionChunkSize</font> <font
color="#000000">()</font><font color="#000000">;</font><br>
<font color="#ffffff"></font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setLoadRevisionCollectionChunkSize</font> <font
color="#000000">(</font><font color="#7f0055"><b>int </b></font><font
color="#000000">loadRevisionCollectionChunkSize</font><font
color="#000000">)</font><font color="#000000">;</font></code> </td>
<!-- end source code --> </tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = -->
<!-- ======================================================== --><br>
- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.<br>
<title></title>
<style type="text/css">
<!--code { font-family: Courier New, Courier; font-size: 10pt; margin: 0px; }-->
</style>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<!-- ======================================================== -->
<!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = -->
<!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"> <code><font color="#7f0055"><b>public class </b></font><font
color="#000000">CDOViewImpl </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">org.eclipse.net4j.internal.util.event.Notifier  </font><font
color="#7f0055"><b>implements </b></font><font color="#000000">CDOView, CDOIDProvider,</font>
<font color="#000000">Adapter.Internal</font><br>
<font color="#000000">{</font><br>
<font color="#ffffff"></font><font color="#ffffff">  </font><font
color="#7f0055"><b>public </b></font><font color="#000000">CDOFeatureAnalyzer getFeatureAnalyzer</font ><font
color="#000000">()</font><br>
<font color="#ffffff">  </font><font color="#000000">{</font><br>
<font color="#ffffff">    </font><font color="#7f0055"><b>return </b></font><font
color="#000000">featureAnalyzer;</font><br>
<font color="#ffffff">  </font><font color="#000000">}</font><br>
<font color="#ffffff"></font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setFeatureAnalyzer</font><font
color="#000000">(</font><font color="#000000">CDOFeatureAnalyzer featureAnalyzer</font ><font
color="#000000">)</font><br>
<font color="#ffffff">  </font><font color="#000000">{</font><br>
<font color="#ffffff">    </font><font color="#7f0055"><b>this</b></font><font
color="#000000">.featureAnalyzer = featureAnalyzer ==  </font><font
color="#7f0055"><b>null </b></font><font color="#000000">? CDOFeatureAnalyzer.NOOP : featureAnalyzer; </font><br>
<font color="#ffffff">  </font><font color="#000000">}</font></code>
</td>
<!-- end source code --> </tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = -->
<!-- ======================================================== --><br>
- There's a SmartReadAheadThread (if you're curious, please ask Simon).<br>
- Caches can be configured<br>
- ...<br>
<br>
<br>
Known issues of the DBStore:<br>
- When in auditing mode updates are always written as complete inserts
(by design)<br>
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.<br>
- No (few) prepared statements are used (see
<a class="moz-txt-link-freetext" href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487">https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487</a>)<br>
- Maybe others...<br>
<br>
Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.<br>
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore. <br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">
This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name="repo1"&gt;
&lt;property name="overrideUUID"
value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name="supportingAudits" value="true"/&gt;
&lt;property name="verifyingRevisions" value="false"/&gt;
&lt;property name="currentLRUCapacity" value="10000"/&gt;
</pre>
</blockquote>
I guess this one could be larger.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap=""> &lt;property name="revisedLRUCapacity" value="100"/&gt;

&lt;store type="db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any user-contributed type&gt; --&gt;
&lt;mappingStrategy type="horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE | ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES --&gt;
&lt;property name="toManyReferences" value="ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES | LIKE_TO_MANY_REFERENCES --&gt;
&lt;property name="toOneReferences" value="LIKE_ATTRIBUTES"/&gt;

&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name="mappingPrecedence" value="MODEL"/&gt;
</pre>
</blockquote>
This one is obsolete.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap=""> &lt;/mappingStrategy&gt;

&lt;dbAdapter name="derby-embedded"/&gt;
&lt;dataSource class="org.apache.derby.jdbc.EmbeddedDataSource"
databaseName="/tmp/cdodb1"
createDatabase="create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ? </pre>
</blockquote>
As I said that's very difficult to judge.<br>
I believe it's more appropriate to compare the actual values with
values from other measures (other setups, properties, etc. or even
other products) instead of random expectations.<br>
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to
grow slowly ;-)<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">What are the main reasons fur such figures ?
</pre>
</blockquote>
Hmm, I *suspect* you don't like the figures? I can find no evidence
your assessment ;-)<br>
<br>
Ahh,one more note:<br>
Tracing can also have a significant impact on performance and
end-to-end throughput.<br>
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
</body>
</html>

--------------090102080203020800020703--
Re: [CDO] reading/writting throughput performances [message #123610 is a reply to message #123598] Thu, 29 May 2008 13:03 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Eike,

thanks for your detailled answer, I'll digg further and try to profile the
Net4J/CDO stack so that I understand the "50 objects/sec rate" when
retrieving data (which I think is surprisingly low).

Concerning the logging, what can I change to be *sure* that no logging will
occurs ?

Cheers,

Cédric



Eike Stepper wrote:

> Hi Cédric,
>
> That sounds interesting!
> Comments inline...
>
>
> Cédric Brun schrieb:
>> Hi Eike,
>>
>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>> measuring read/write throughput when I use CDO (RC2).
>>
>> I'm using an embeded-derby database, two different metamodels (complex
>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>> Features)
>>
>> The test is a "quick and dirty" one so please do not take these figures
>> too seriously, I would just like to have your input about the "order of
>> magnitude" I should expect or settings affecting seriously these
>> performances. I tried both JVM and TCP acceptor but the performances are
>> quite similar though JVM is a bit faster.
>>
> Looks like a sign that the NIO socket channels are efficient ,-)
> You used localhost for TCP transport I guess?
>
>>
>> * First case : building a small model (10000 elements) with the simple
>> MM, only adding instances in an empty database :
>> commiting change on every add I get a 2 objects per second rate.
>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>
> Seems to be consistent with the fact that only for commits there is
> remote traffic.
> And the backend transaction management is another overhead.
> So the impact of the number objects/commit starts with bigger
> transactions.
>
>> browsing the just commited elements opening a new transaction and getting
>> a new Resource instance, I get around 30 000 objets/sec rate just
>> iterating thanks to Resource.getAllContents().
>>
> Hehe, this is a sign that client side caching works well:
> All views and transactions of a single session share (and cache) their
> object state.
> Otherwise I'd expect much smaller values.
> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
> several thousands objects/sec.
> But the DBStore (which you used) is not that optimized.
>
>> * Second case : I built a big model in the database using the complex
>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>> (I did not measured it exactly as it was launched during a night, but it
>> seems I got around 100 objects/sec rate in writting as I was writting
>> every 700 objects.
>>
> Sounds not too bad.
>
>>
>> Once the model is built the derby database is 222 MB (which - I heard -
>> is not so big for derby).
>>
> Hmm, I have no extensive experience with Derby.
> To be honest, I'm really no database expert (although I can write simple
> SQL statements).
>
>> Retrieving the distant resource and calling eAllContents() on it, I get a
>> 50 Objects/sec rate at best, which mean my eAllContents() call would take
>> 4 hours !
>>
> Currently I'm not sure what exactly eAllContents() does do (iteration
> order and so).
> There are several CDO features that can have a major impact on load rates!
>
> - Collections (xrefs and containment) can be loaded lazily. I don't mean
> the target objects, which are lazy by default anyway, but even the
> target IDs that are in the collections. We call that "reference
> chunking" (but search for a better name is ongoing).
> |*public interface *CDOSession *extends *CDOProtocolSession,
> |IContainer<CDOView>
> {
> *public **int *getReferenceChunkSize();
>
> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>
>
> - Loading collection elements (target objects) can be batched (the
> current name is even worse)
> |*public interface *CDOView *extends *CDOProtocolView, INotifier
> {
> *public **int *getLoadRevisionCollectionChunkSize();
>
> *public **void *setLoadRevisionCollectionChunkSize(*int
> *loadRevisionCollectionChunkSize);|
>
>
>
> - One of the most sophisticated feature is automatic model usage
> analyzation. The result are fetch rules that are sent to the server.
> When later objects are loaded from the server, it can answer with
> additional objects that are likely to be needed by the client in the
> near future.
> |*public class *CDOViewImpl *extends
> |*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
> |CDOIDProvider,
> Adapter.Internal
> {
> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
> {
> *return *featureAnalyzer;
> }
>
> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
> {
> *this*.featureAnalyzer = featureAnalyzer == *null *?
> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
> }|
>
>
> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
> - Caches can be configured
> - ...
>
>
> Known issues of the DBStore:
> - When in auditing mode updates are always written as complete inserts
> (by design)
> - When configuring toManyReferences to a value different from
> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
> - No (few) prepared statements are used (see
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
> - Maybe others...
>
> Please note that the DBStore was not written by me to compete with
> Hibernate in terms of performance or mapping capabilities.
> Now that Martin and I, well in the end mostly Martin, provide a
> HibernateStore and this HibernateStore gets more and more features I
> expect that there will be a trend away from the DBStore.
>
>> This is probably linked to the way the mapping to db is done, here's the
>> config I used (came from CDO-server example if I recall correctly).
>>
>>
>> <repository name="repo1">
>> <property name="overrideUUID"
>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>> <property name="supportingAudits" value="true"/>
>> <property name="verifyingRevisions" value="false"/>
>> <property name="currentLRUCapacity" value="10000"/>
>>
> I guess this one could be larger.
>
>> <property name="revisedLRUCapacity" value="100"/>
>>
>> <store type="db">
>> <!-- type: horizontal | vertical | <any
>> user-contributed type> --> <mappingStrategy
>> type="horizontal">
>> <!-- ONE_TABLE_PER_REFERENCE |
>> ONE_TABLE_PER_CLASS |
>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>> <property name="toManyReferences"
>> value="ONE_TABLE_PER_REFERENCE"/>
>>
>> <!-- LIKE_ATTRIBUTES |
>> LIKE_TO_MANY_REFERENCES --> <property
>> name="toOneReferences"
>> value="LIKE_ATTRIBUTES"/>
>>
>> <!-- MODEL | STRATEGY -->
>> <property name="mappingPrecedence"
>> value="MODEL"/>
>>
> This one is obsolete.
>
>> </mappingStrategy>
>>
>> <dbAdapter name="derby-embedded"/>
>> <dataSource
>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>> databaseName="/tmp/cdodb1"
>> createDatabase="create"/>
>>
>> </store>
>> </repository>
>>
>>
>>
>>
>> What do you think about that ? What throughput do you think I should
>> expect ?
> As I said that's very difficult to judge.
> I believe it's more appropriate to compare the actual values with values
> from other measures (other setups, properties, etc. or even other
> products) instead of random expectations.
> Apologies that I didn't have the time so far to provide some reference
> measures myself. Maybe this gets better now that the team starts to grow
> slowly ;-)
>
>> What are the main reasons fur such figures ?
>>
> Hmm, I *suspect* you don't like the figures? I can find no evidence your
> assessment ;-)
>
> Ahh,one more note:
> Tracing can also have a significant impact on performance and end-to-end
> throughput.
> Turn it off by all means. And please make sure that it's really turned
> off, not only invisible (i.e. console is not a target).
>
> Cheers
> /Eike


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #123623 is a reply to message #123598] Thu, 29 May 2008 13:46 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Eike,

As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
relevant, but in the testcase I'm working on (with the complex metamodel,
big model in database and 50 o/sec throughput) my profiler says that most
of the time (like 99.9%) is spent in a readString call from
CDOClassRefImpl :

public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
IOException
{
// TODO Optimize transfer of URIs
packageURI = in.readString();
if (packageURI == null)
{
packageURI = defaultURI;
}

classifierID = in.readInt();
}

The TODO let me think this seems relevant but I'm not sure, what do you
think of it ?

Cédric


Eike Stepper wrote:

> Hi Cédric,
>
> That sounds interesting!
> Comments inline...
>
>
> Cédric Brun schrieb:
>> Hi Eike,
>>
>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>> measuring read/write throughput when I use CDO (RC2).
>>
>> I'm using an embeded-derby database, two different metamodels (complex
>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>> Features)
>>
>> The test is a "quick and dirty" one so please do not take these figures
>> too seriously, I would just like to have your input about the "order of
>> magnitude" I should expect or settings affecting seriously these
>> performances. I tried both JVM and TCP acceptor but the performances are
>> quite similar though JVM is a bit faster.
>>
> Looks like a sign that the NIO socket channels are efficient ,-)
> You used localhost for TCP transport I guess?
>
>>
>> * First case : building a small model (10000 elements) with the simple
>> MM, only adding instances in an empty database :
>> commiting change on every add I get a 2 objects per second rate.
>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>
> Seems to be consistent with the fact that only for commits there is
> remote traffic.
> And the backend transaction management is another overhead.
> So the impact of the number objects/commit starts with bigger
> transactions.
>
>> browsing the just commited elements opening a new transaction and getting
>> a new Resource instance, I get around 30 000 objets/sec rate just
>> iterating thanks to Resource.getAllContents().
>>
> Hehe, this is a sign that client side caching works well:
> All views and transactions of a single session share (and cache) their
> object state.
> Otherwise I'd expect much smaller values.
> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
> several thousands objects/sec.
> But the DBStore (which you used) is not that optimized.
>
>> * Second case : I built a big model in the database using the complex
>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>> (I did not measured it exactly as it was launched during a night, but it
>> seems I got around 100 objects/sec rate in writting as I was writting
>> every 700 objects.
>>
> Sounds not too bad.
>
>>
>> Once the model is built the derby database is 222 MB (which - I heard -
>> is not so big for derby).
>>
> Hmm, I have no extensive experience with Derby.
> To be honest, I'm really no database expert (although I can write simple
> SQL statements).
>
>> Retrieving the distant resource and calling eAllContents() on it, I get a
>> 50 Objects/sec rate at best, which mean my eAllContents() call would take
>> 4 hours !
>>
> Currently I'm not sure what exactly eAllContents() does do (iteration
> order and so).
> There are several CDO features that can have a major impact on load rates!
>
> - Collections (xrefs and containment) can be loaded lazily. I don't mean
> the target objects, which are lazy by default anyway, but even the
> target IDs that are in the collections. We call that "reference
> chunking" (but search for a better name is ongoing).
> |*public interface *CDOSession *extends *CDOProtocolSession,
> |IContainer<CDOView>
> {
> *public **int *getReferenceChunkSize();
>
> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>
>
> - Loading collection elements (target objects) can be batched (the
> current name is even worse)
> |*public interface *CDOView *extends *CDOProtocolView, INotifier
> {
> *public **int *getLoadRevisionCollectionChunkSize();
>
> *public **void *setLoadRevisionCollectionChunkSize(*int
> *loadRevisionCollectionChunkSize);|
>
>
>
> - One of the most sophisticated feature is automatic model usage
> analyzation. The result are fetch rules that are sent to the server.
> When later objects are loaded from the server, it can answer with
> additional objects that are likely to be needed by the client in the
> near future.
> |*public class *CDOViewImpl *extends
> |*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
> |CDOIDProvider,
> Adapter.Internal
> {
> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
> {
> *return *featureAnalyzer;
> }
>
> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
> {
> *this*.featureAnalyzer = featureAnalyzer == *null *?
> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
> }|
>
>
> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
> - Caches can be configured
> - ...
>
>
> Known issues of the DBStore:
> - When in auditing mode updates are always written as complete inserts
> (by design)
> - When configuring toManyReferences to a value different from
> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
> - No (few) prepared statements are used (see
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
> - Maybe others...
>
> Please note that the DBStore was not written by me to compete with
> Hibernate in terms of performance or mapping capabilities.
> Now that Martin and I, well in the end mostly Martin, provide a
> HibernateStore and this HibernateStore gets more and more features I
> expect that there will be a trend away from the DBStore.
>
>> This is probably linked to the way the mapping to db is done, here's the
>> config I used (came from CDO-server example if I recall correctly).
>>
>>
>> <repository name="repo1">
>> <property name="overrideUUID"
>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>> <property name="supportingAudits" value="true"/>
>> <property name="verifyingRevisions" value="false"/>
>> <property name="currentLRUCapacity" value="10000"/>
>>
> I guess this one could be larger.
>
>> <property name="revisedLRUCapacity" value="100"/>
>>
>> <store type="db">
>> <!-- type: horizontal | vertical | <any
>> user-contributed type> --> <mappingStrategy
>> type="horizontal">
>> <!-- ONE_TABLE_PER_REFERENCE |
>> ONE_TABLE_PER_CLASS |
>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>> <property name="toManyReferences"
>> value="ONE_TABLE_PER_REFERENCE"/>
>>
>> <!-- LIKE_ATTRIBUTES |
>> LIKE_TO_MANY_REFERENCES --> <property
>> name="toOneReferences"
>> value="LIKE_ATTRIBUTES"/>
>>
>> <!-- MODEL | STRATEGY -->
>> <property name="mappingPrecedence"
>> value="MODEL"/>
>>
> This one is obsolete.
>
>> </mappingStrategy>
>>
>> <dbAdapter name="derby-embedded"/>
>> <dataSource
>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>> databaseName="/tmp/cdodb1"
>> createDatabase="create"/>
>>
>> </store>
>> </repository>
>>
>>
>>
>>
>> What do you think about that ? What throughput do you think I should
>> expect ?
> As I said that's very difficult to judge.
> I believe it's more appropriate to compare the actual values with values
> from other measures (other setups, properties, etc. or even other
> products) instead of random expectations.
> Apologies that I didn't have the time so far to provide some reference
> measures myself. Maybe this gets better now that the team starts to grow
> slowly ;-)
>
>> What are the main reasons fur such figures ?
>>
> Hmm, I *suspect* you don't like the figures? I can find no evidence your
> assessment ;-)
>
> Ahh,one more note:
> Tracing can also have a significant impact on performance and end-to-end
> throughput.
> Turn it off by all means. And please make sure that it's really turned
> off, not only invisible (i.e. console is not a target).
>
> Cheers
> /Eike


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #123651 is a reply to message #123598] Thu, 29 May 2008 16:13 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
This is a multi-part message in MIME format.

------=_NextPart_000_04AC_01C8C185.678D3E20
Content-Type: text/plain;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

We noticed a performance degradation in the following case:
=20
When we fetch a collection of objects that contains collections that we =
don't want to use.=20
Ex:
=20
Model:
=20
ClassB
{
int foo1;
List childrens1;
List childrens2;
List childrens3;
};
=20
Code:

Resource.contents contains objects of type ClassB.
=20
By fetching instances of classB, we will also fetched some items in the =
list(childrens1, childrens2, childrens3) The problem we had.. is we do =
not know if we want to use it. SO better not to download them.

So In our production(we used our own IStore), we never download any =
objects from collection.=20
I'm working at the moment to put in place all feature we used in the =
current CDO.
That one will be part of=20
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477. To begin =
with,CDORevisionImpl needs to supports list that are 0 even if =
referenceChunkSize =3D=3D 0.
=20
It is true that we obtain good performance.
Worst case :
1500 objects /sec (Real fetch from disk. Page that contains the objects, =
wasn't in the cache of the filesystem.)=20
=20
Best case=20
12 000 objects/Sec (Fetch objects that are already in the case of the =
filesystem)
=20
(These statistics always fetch objects from server to client. The cache =
client isn't used)
=20
We have another optimization one with SmartReadAhead but for now only =
work for UI client. (for now) This is something we will integrate as =
well in CDO. But for now we concentrate on the other things.
=20
I used an Object database. Based on my preliminary test without CDO.
I compare
=20
Hibernate vs Objectivity/EMF :=20
Objectivity/EMF is around 3 to 50 times faster than Hibernate.
=20
The worst.. you will get 30 to 240 objects/sec or
the best... you will get 500 to 4000 objects/sec
=20
Based on your comments... you are getting the worst (with Derby)!! :-)
=20
=20
Another comments about insertion.
=20
We found another problem when we insert data(DOn't know if it is still =
true). Resource.Contents is a unique list. Basically each time we insert =
one element, it needs to fetch all the collection to see if we already =
have this element. Basically.. it is time consuming. In our case we are =
not going through this stage to persist our objects... but the objects =
are not accessible through that list.
=20


If speed is an issue for you!! We (You included :-)) can optimize it. =
What I like is Eike did a really good job doing that framwork and =
optimizations are easy to add.
Also you can change your back-end without affecting you client side. =
(Maybe going to an Object database!!)
THis was one of the purpose of CDO!! :-)


Simon


"Eike Stepper" <stepper@sympedia.de> a =C3=A9crit dans le message de =
news: 483E9332.6050800@sympedia.de...
Hi C=C3=A9dric,

That sounds interesting!
Comments inline...


C=C3=A9dric Brun schrieb:=20
Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex =
one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 =
Features)

The test is a "quick and dirty" one so please do not take these figures =
too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?



* First case : building a small model (10000 elements) with the simple =
MM,
only adding instances in an empty database :=20
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
Seems to be consistent with the fact that only for commits there is =
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger =
transactions.


browsing the just commited elements opening a new transaction and =
getting a
new Resource instance, I get around 30 000 objets/sec rate just =
iterating
thanks to Resource.getAllContents().
Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) their =
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates =
of several thousands objects/sec.
But the DBStore (which you used) is not that optimized.


* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely =
(I
did not measured it exactly as it was launched during a night, but it =
seems
I got around 100 objects/sec rate in writting as I was writting every =
700
objects.
Sounds not too bad.



Once the model is built the derby database is 222 MB (which - I heard - =
is
not so big for derby).
Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write =
simple SQL statements).


Retrieving the distant resource and calling eAllContents() on it, I get =
a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
Currently I'm not sure what exactly eAllContents() does do (iteration =
order and so).
There are several CDO features that can have a major impact on load =
rates!

- Collections (xrefs and containment) can be loaded lazily. I don't =
mean the target objects, which are lazy by default anyway, but even the =
target IDs that are in the collections. We call that "reference =
chunking" (but search for a better name is ongoing).

public interface CDOSession extends CDOProtocolSession, =
IContainer<CDOView>
{
public int getReferenceChunkSize();

public void setReferenceChunkSize(int referenceChunkSize); =20


- Loading collection elements (target objects) can be batched (the =
current name is even worse)

public interface CDOView extends CDOProtocolView, INotifier
{
public int getLoadRevisionCollectionChunkSize();

public void setLoadRevisionCollectionChunkSize(int =
loadRevisionCollectionChunkSize); =20


- One of the most sophisticated feature is automatic model usage =
analyzation. The result are fetch rules that are sent to the server. =
When later objects are loaded from the server, it can answer with =
additional objects that are likely to be needed by the client in the =
near future.

public class CDOViewImpl extends =
org.eclipse.net4j.internal.util.event.Notifier implements CDOView, =
CDOIDProvider, Adapter.Internal
{
public CDOFeatureAnalyzer getFeatureAnalyzer()
{
return featureAnalyzer;
}

public void setFeatureAnalyzer(CDOFeatureAnalyzer =
featureAnalyzer)
{
this.featureAnalyzer =3D featureAnalyzer =3D=3D null ? =
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
} =20


- There's a SmartReadAheadThread (if you're curious, please ask =
Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts =
(by design)
- When configuring toManyReferences to a value different from =
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see =
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487)
- Maybe others...

Please note that the DBStore was not written by me to compete with =
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a =
HibernateStore and this HibernateStore gets more and more features I =
expect that there will be a trend away from the DBStore.=20


This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


<repository name=3D"repo1">
<property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
<property name=3D"supportingAudits" value=3D"true"/>
<property name=3D"verifyingRevisions" value=3D"false"/>
<property name=3D"currentLRUCapacity" value=3D"10000"/>
I guess this one could be larger.


<property name=3D"revisedLRUCapacity" value=3D"100"/>
=20
<store type=3D"db">
<!-- type: horizontal | vertical | <any =
user-contributed type> -->
<mappingStrategy type=3D"horizontal">
<!-- ONE_TABLE_PER_REFERENCE | =
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
<property name=3D"toManyReferences" =
value=3D"ONE_TABLE_PER_REFERENCE"/>

<!-- LIKE_ATTRIBUTES | =
LIKE_TO_MANY_REFERENCES -->
<property name=3D"toOneReferences" =
value=3D"LIKE_ATTRIBUTES"/>
=20
<!-- MODEL | STRATEGY -->
<property name=3D"mappingPrecedence" =
value=3D"MODEL"/>
This one is obsolete.


</mappingStrategy>
=20
<dbAdapter name=3D"derby-embedded"/>
<dataSource =
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"=20
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/>

</store>
</repository>




What do you think about that ? What throughput do you think I should
expect ? As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with =
values from other measures (other setups, properties, etc. or even other =
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference =
measures myself. Maybe this gets better now that the team starts to grow =
slowly ;-)


What are the main reasons fur such figures ?
Hmm, I *suspect* you don't like the figures? I can find no evidence =
your assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and =
end-to-end throughput.
Turn it off by all means. And please make sure that it's really turned =
off, not only invisible (i.e. console is not a target).

Cheers
/Eike



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<DIV>We noticed a performance degradation in the following=20
case:<BR>&nbsp;<BR>When we fetch a collection of objects that contains=20
collections that we don't want to use.=20
<BR>Ex:<BR>&nbsp;<BR>Model:<BR>&nbsp;<BR>ClassB <BR>{<BR>&nbsp; int=20
foo1;<BR>&nbsp; List childrens1;<BR>&nbsp; List childrens2;<BR>&nbsp; =
List=20
childrens3;<BR>};<BR>&nbsp;<BR>Code:</DIV>
<DIV><BR>Resource.contents contains objects of type =
ClassB.<BR>&nbsp;<BR>By=20
fetching instances of classB, we will also fetched some items in the=20
list(childrens1, childrens2, childrens3)&nbsp;<FONT face=3D"Courier =
New"><FONT=20
color=3D#000000>The problem we had.. is we do not know if we want to use =
it. SO=20
better not to download them.</FONT></FONT></DIV><FONT face=3D"Courier =
New"></FONT>
<DIV><BR><FONT face=3D"Courier New" color=3D#000000>So In our =
production(we used our=20
own IStore), we never download any objects from collection. =
</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000>I'm working at the moment to put in =
place all=20
feature we used in the current CDO.</FONT><BR><FONT face=3D"Courier New" =

color=3D#000000>That one will be part of </FONT><BR><A=20
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477" =
target=3D_blank><FONT=20
color=3D#0068cf>https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477</F=
ONT></A>.=20
To begin with,CDORevisionImpl needs to supports list that are 0 even if =
<FONT=20
face=3D"Courier New" color=3D#000000>referenceChunkSize =3D=3D =
0.</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000></FONT>&nbsp;<BR><FONT =
face=3D"Courier New"=20
color=3D#000000>It is true that we obtain good =
performance.</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000>Worst case :</FONT><BR><FONT =
face=3D"Courier New"=20
color=3D#000000>1500 objects /sec (Real fetch from&nbsp;disk. Page that =
contains=20
the objects, wasn't in the cache of the =
filesystem.)&nbsp;</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000></FONT>&nbsp;<BR><FONT =
face=3D"Courier New"=20
color=3D#000000>Best case </FONT><BR><FONT face=3D"Courier New" =
color=3D#000000>12 000=20
objects/Sec (Fetch objects that are already in the case of the=20
filesystem)</FONT><BR><FONT face=3D"Courier New"=20
color=3D#000000></FONT>&nbsp;<BR>(These statistics always fetch objects =
from=20
server to client. The cache client isn't used)<BR>&nbsp;<BR><FONT=20
face=3D"Courier New" color=3D#000000>We have another optimization one =
with=20
SmartReadAhead but for now only work for UI client. (for now)&nbsp; This =
is=20
something we will integrate as well in CDO. But for now we concentrate =
on the=20
other things.</FONT><BR><FONT face=3D"Courier New"=20
color=3D#000000></FONT>&nbsp;<BR><FONT face=3D"Courier New" =
color=3D#000000>I used an=20
Object database. Based on my preliminary test without =
CDO.</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000>I compare</FONT><BR><FONT =
face=3D"Courier New"=20
color=3D#000000></FONT>&nbsp;<BR><FONT face=3D"Courier New" =
color=3D#000000>Hibernate=20
vs </FONT><FONT face=3D"Courier New" color=3D#000000>Objectivity/EMF=20
:&nbsp;</FONT><BR><FONT face=3D"Courier New" =
color=3D#000000>Objectivity/EMF is=20
around 3 to 50 times faster than Hibernate.</FONT><BR><FONT =
face=3D"Courier New"=20
color=3D#000000></FONT>&nbsp;<BR><FONT face=3D"Courier New" =
color=3D#000000>The=20
worst.. you will get 30 to 240 objects/sec or</FONT><BR><FONT =
face=3D"Courier New"=20
color=3D#000000>the best... you will get 500 to 4000 =
objects/sec</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000></FONT>&nbsp;<BR><FONT =
face=3D"Courier New"=20
color=3D#000000>Based on your comments... you are getting the worst =
(with Derby)!!=20
:-)</FONT><BR>&nbsp;<BR>&nbsp;<BR>Another comments about=20
insertion.<BR>&nbsp;<BR>We found another problem when we insert =
data(DOn't know=20
if it is still true). Resource.Contents is&nbsp;a unique list. Basically =
each=20
time we insert one element, it needs to fetch all the collection to see =
if we=20
already have this element. Basically.. it is time consuming. In our case =
we are=20
not going through this stage to persist our objects... but the objects =
are not=20
accessible through that list.<BR>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>If speed is an issue for you!! We (You =
included=20
:-)) can optimize it. What I like is Eike did a really good job doing =
that=20
framwork and optimizations are easy to add.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Also you can change your back-end =
without affecting=20
you client side. (Maybe going to an Object database!!)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>THis was one of the purpose of CDO!!=20
:-)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><BR>Simon<BR><BR></DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Eike Stepper" &lt;<A=20
href=3D"mailto:stepper@sympedia.de">stepper@sympedia.de</A>&gt; a =
=C3=A9crit dans le=20
message de news: <A=20
=
href=3D"mailto:483E9332.6050800@sympedia.de">483E9332.6050800@sympedia.de=
</A>...</DIV>Hi=20
C=C3=A9dric,<BR><BR>That sounds interesting!<BR>Comments=20
inline...<BR><BR><BR>C=C3=A9dric Brun schrieb:=20
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex =
one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 =
Features)

The test is a "quick and dirty" one so please do not take these figures =
too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
</PRE></BLOCKQUOTE>Looks like a sign that the NIO socket channels are=20
efficient ,-)<BR>You used localhost for TCP transport I guess?<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">
* First case : building a small model (10000 elements) with the simple =
MM,
only adding instances in an empty database :=20
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
</PRE></BLOCKQUOTE>Seems to be consistent with the fact that only for=20
commits there is remote traffic.<BR>And the backend transaction =
management is=20
another overhead.<BR>So the impact of the number objects/commit starts =
with=20
bigger transactions.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">browsing the just commited elements opening =
a new transaction and getting a
new Resource instance, I get around 30 000 objets/sec rate just =
iterating
thanks to Resource.getAllContents().
</PRE></BLOCKQUOTE>Hehe, this is a sign that client side caching works =

well:<BR>All views and transactions of a single session share (and =
cache)=20
their object state.<BR>Otherwise I'd expect much smaller =
values.<BR>With his=20
ObjectivityStore implementation Simon (cc'ed) reached rates of several =

thousands objects/sec.<BR>But the DBStore (which you used) is not that =

optimized.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">* Second case : I built a big model in the =
database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely =
(I
did not measured it exactly as it was launched during a night, but it =
seems
I got around 100 objects/sec rate in writting as I was writting every =
700
objects.
</PRE></BLOCKQUOTE>Sounds not too bad.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">
Once the model is built the derby database is 222 MB (which - I heard - =
is
not so big for derby).
</PRE></BLOCKQUOTE>Hmm, I have no extensive experience with =
Derby.<BR>To be=20
honest, I'm really no database expert (although I can write simple SQL =

statements).<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Retrieving the distant resource and calling =
eAllContents() on it, I get a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
</PRE></BLOCKQUOTE>Currently I'm not sure what exactly eAllContents() =
does=20
do (iteration order and so).<BR>There are several CDO features that =
can have a=20
major impact on load rates!<BR><BR>- Collections (xrefs and =
containment) can=20
be loaded lazily. I don't mean the target objects, which are lazy by =
default=20
anyway, but even the target IDs that are in the collections. We call =
that=20
"reference chunking" (but search for a better name is ongoing).<BR>
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
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<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff border=3D0>
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<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
color=3D#7f0055><B>public&nbsp;interface&nbsp;</B ></FONT><FONT=20
color=3D#000000>CDOSession&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
=
color=3D#000000> CDOProtocolSession,&nbsp;IContainer&lt;CDOView&g t; </FONT>=
<BR><FONT=20
color=3D#000000>{</FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>getReferenceChunkSize</FONT><FONT=20
color=3D#000000>()</FONT><FONT color=3D#000000>;</FONT><BR><FONT =

color=3D#ffffff></FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setReferenceChunkSize</FONT><FONT=20
color=3D#000000>(</FONT><FONT =
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>referenceChunkSize</FONT><FONT =
color=3D#000000>)</FONT><FONT=20
color=3D#000000>;</FONT></CODE>=20
</TD><!-- end source code --></TR></TBODY></TABLE></DIV><!-- =3D =
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=3D=3D=3D=3D=3D=3D -->-=20
Loading collection elements (target objects) can be batched (the =
current name=20
is even worse)<BR>
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
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<DIV class=3Djava align=3Dleft>
<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff border=3D0>
<TBODY>
<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
color=3D#7f0055><B>public&nbsp;interface&nbsp;</B ></FONT><FONT=20
color=3D#000000>CDOView&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
color=3D#000000>CDOProtocolView,&nbsp;INotifier</FONT> <BR><FONT=20
color=3D#000000>{</FONT><BR><FONT color=3D#ffffff></FONT><FONT=20
color=3D#ffffff>&nbsp; </FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>getLoadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>()</FONT><FONT color=3D#000000>;</FONT><BR><FONT =

color=3D#ffffff></FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setLoadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>(</FONT><FONT =
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>loadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>)</FONT><FONT color=3D#000000>;</FONT></CODE> =
</TD><!-- end source code --></TR></TBODY></TABLE></DIV><!-- =3D =
END of automatically generated HTML code =3D --><!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D --><BR>-=20
One of the most sophisticated feature is automatic model usage =
analyzation.=20
The result are fetch rules that are sent to the server. When later =
objects are=20
loaded from the server, it can answer with additional objects that are =
likely=20
to be needed by the client in the near future.<BR>
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<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff border=3D0>
<TBODY>
<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
color=3D#7f0055><B>public&nbsp;class&nbsp;</B></FONT ><FONT=20
color=3D#000000>CDOViewImpl&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
=
color=3D#000000>org.eclipse.net4j.internal.util.event.Notifier&nbsp; </FON=
T><FONT=20
color=3D#7f0055><B>implements&nbsp;</B></FONT><FONT=20
color=3D#000000>CDOView,&nbsp;CDOIDProvider,</FONT> <FONT=20
color=3D#000000>Adapter.Internal</FONT><BR><FONT=20
color=3D#000000>{</FONT><BR><FONT color=3D#ffffff></FONT><FONT=20
color=3D#ffffff>&nbsp; </FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
=
color=3D#000000>CDOFeatureAnalyzer&nbsp;getFeatureAnalyzer </FONT><FONT=20
color=3D#000000>()</FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>return&nbsp;</B></FONT><FONT=20
color=3D#000000>featureAnalyzer;</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT =
color=3D#000000>}</FONT><BR><FONT=20
color=3D#ffffff></FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setFeatureAnalyzer</FONT><FONT =
color=3D#000000>(</FONT><FONT=20
=
color=3D#000000>CDOFeatureAnalyzer&nbsp;featureAnalyzer </FONT><FONT=20
color=3D#000000>)</FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>this</B></FONT><FONT=20
=
color=3D#000000> .featureAnalyzer&nbsp;=3D&nbsp;featureAnalyzer&n bsp;=3D=3D=
&nbsp;</FONT><FONT=20
color=3D#7f0055><B>null&nbsp;</B></FONT><FONT=20
=
color=3D#000000> ?&nbsp;CDOFeatureAnalyzer.NOOP&nbsp;:&nbsp;featu reAnalyze=
r;</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT =
color=3D#000000>}</FONT></CODE> </TD><!-- end source code =
--></TR></TBODY></TABLE></DIV><!-- =3D END of automatically =
generated HTML code =3D --><!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D --><BR>-=20
There's a SmartReadAheadThread (if you're curious, please ask =
Simon).<BR>-=20
Caches can be configured<BR>- ...<BR><BR><BR>Known issues of the =
DBStore:<BR>-=20
When in auditing mode updates are always written as complete inserts =
(by=20
design)<BR>- When configuring toManyReferences to a value different =
from=20
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.<BR>- =
No (few)=20
prepared statements are used (see <A class=3Dmoz-txt-link-freetext=20
=
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487">https://b=
ugs.eclipse.org/bugs/show_bug.cgi?id=3D214487</A>)<BR>-=20
Maybe others...<BR><BR>Please note that the DBStore was not written by =
me to=20
compete with Hibernate in terms of performance or mapping =
capabilities.<BR>Now=20
that Martin and I, well in the end mostly Martin, provide a =
HibernateStore and=20
this HibernateStore gets more and more features I expect that there =
will be a=20
trend away from the DBStore. <BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">This is probably linked to the way the =
mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name=3D"repo1"&gt;
&lt;property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name=3D"supportingAudits" =
value=3D"true"/&gt;
&lt;property name=3D"verifyingRevisions" =
value=3D"false"/&gt;
&lt;property name=3D"currentLRUCapacity" =
value=3D"10000"/&gt;
</PRE></BLOCKQUOTE>I guess this one could be larger.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D""> &lt;property =
name=3D"revisedLRUCapacity" value=3D"100"/&gt;
=20
&lt;store type=3D"db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any =
user-contributed type&gt; --&gt;
&lt;mappingStrategy type=3D"horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE | =
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES =
--&gt;
&lt;property name=3D"toManyReferences" =
value=3D"ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES | =
LIKE_TO_MANY_REFERENCES --&gt;
&lt;property name=3D"toOneReferences" =
value=3D"LIKE_ATTRIBUTES"/&gt;
=20
&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name=3D"mappingPrecedence" =
value=3D"MODEL"/&gt;
</PRE></BLOCKQUOTE>This one is obsolete.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D""> =
&lt;/mappingStrategy&gt;
=20
&lt;dbAdapter name=3D"derby-embedded"/&gt;
&lt;dataSource =
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"=20
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ? </PRE></BLOCKQUOTE>As I said that's very difficult to =
judge.<BR>I=20
believe it's more appropriate to compare the actual values with values =
from=20
other measures (other setups, properties, etc. or even other products) =
instead=20
of random expectations.<BR>Apologies that I didn't have the time so =
far to=20
provide some reference measures myself. Maybe this gets better now =
that the=20
team starts to grow slowly ;-)<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">What are the main reasons fur such figures =
?
</PRE></BLOCKQUOTE>Hmm, I *suspect* you don't like the figures? I can =
find=20
no evidence your assessment ;-)<BR><BR>Ahh,one more note:<BR>Tracing =
can also=20
have a significant impact on performance and end-to-end =
throughput.<BR>Turn it=20
off by all means. And please make sure that it's really turned off, =
not only=20
invisible (i.e. console is not a=20
target).<BR><BR>Cheers<BR>/Eike<BR><BR><BR></BLOCKQUOTE ></BODY></HTML>

------=_NextPart_000_04AC_01C8C185.678D3E20--
Re: [CDO] reading/writting throughput performances [message #123664 is a reply to message #123623] Thu, 29 May 2008 16:23 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
Did you disable the following :
CDOSessionConfigurationImpl.setLegacySupportEnabled(true);

before opening your session ?

This could cause what you are observing ?

If your classes are generating with CDOObjectImpl as the super class, you
can disableLegacySupport by putting it at true.

Simon


"C
Re: [CDO] reading/writting throughput performances [message #123681 is a reply to message #123664] Thu, 29 May 2008 16:28 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------090803020509090708070909
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Content-Transfer-Encoding: 8bit



Simon McDuff schrieb:
> Did you disable the following :
> CDOSessionConfigurationImpl.setLegacySupportEnabled(true);
>
> before opening your session ?
>
> This could cause what you are observing ?
>
> If your classes are generating with CDOObjectImpl as the super class, you
> can disableLegacySupport by putting it at true.
>
Good point in general!

But I added some logic some time ago that ensures that *session legacy
support* can only be enabled if the *legacy system* is available in general:

| *public **void *setDisableLegacyObjects(*boolean *disableLegacyObjects)
{
checkInactive();
*if *(!disableLegacyObjects && !FSMUtil.isLegacySystemAvailable())
{
*throw new *LegacySystemNotAvailableException();
}

*this*.disableLegacyObjects = disableLegacyObjects;
}|


Notice that the whole legacy system is currently (since the work on the
HibernateStore) broken.
The needed CDOWeaver is currently not part of the distro anymore (also
due to issues with the build system).

This altogether seems to exclude the legacy system as root cause for
performance degradation.

Cheers
/Eike



> Simon
>
>
> "C
Re: [CDO] reading/writting throughput performances [message #123696 is a reply to message #123681] Thu, 29 May 2008 16:41 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
This is a multi-part message in MIME format.

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charset="ISO-8859-15"
Content-Transfer-Encoding: quoted-printable

Good point Eike,

Cedric,

How do you create your CDOSessionIMpl ?
Are you using your own mechanism ?

Because it could still occured in the case we doesn`t go through =
CDOSessionConfigurationImpl and create directly the CDOSession

Ex:

CDOSession session =3D CDOSessionImpl();

By default disablyLegacySystem is false.

In this case Eike, Do we have something else to avoid that ? Maybe I`m =
not aware of other mechanism.

Simon

"Eike Stepper" <stepper@sympedia.de> a =E9crit dans le message de news: =
483ED9A4.7010302@sympedia.de...


Simon McDuff schrieb:=20
Did you disable the following :
CDOSessionConfigurationImpl.setLegacySupportEnabled(true);

before opening your session ?

This could cause what you are observing ?

If your classes are generating with CDOObjectImpl as the super class, =
you=20
can disableLegacySupport by putting it at true.
Good point in general!

But I added some logic some time ago that ensures that *session legacy =
support* can only be enabled if the *legacy system* is available in =
general:


public void setDisableLegacyObjects(boolean =
disableLegacyObjects)
{
checkInactive();
if (!disableLegacyObjects && =
!FSMUtil.isLegacySystemAvailable())
{
throw new LegacySystemNotAvailableException();
}

this.disableLegacyObjects =3D disableLegacyObjects;
} =20


Notice that the whole legacy system is currently (since the work on =
the HibernateStore) broken.
The needed CDOWeaver is currently not part of the distro anymore (also =
due to issues with the build system).

This altogether seems to exclude the legacy system as root cause for =
performance degradation.

Cheers
/Eike




Simon


"C=E9dric Brun" <cedric.brun@obeo.fr> a =E9crit dans le message de news: =

g1mbhe$2cl$1@build.eclipse.org...
Eike,

As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
relevant, but in the testcase I'm working on (with the complex =
metamodel,
big model in database and 50 o/sec throughput) my profiler says that =
most
of the time (like 99.9%) is spent in a readString call from
CDOClassRefImpl :

public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
IOException
{
// TODO Optimize transfer of URIs
packageURI =3D in.readString();
if (packageURI =3D=3D null)
{
packageURI =3D defaultURI;
}

classifierID =3D in.readInt();
}

The TODO let me think this seems relevant but I'm not sure, what do you
think of it ?

C=E9dric


Eike Stepper wrote:

Hi C=E9dric,

That sounds interesting!
Comments inline...


C=E9dric Brun schrieb:
Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex
one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
Features)

The test is a "quick and dirty" one so please do not take these figures
too seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.

Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?

* First case : building a small model (10000 elements) with the =
simple
MM, only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.

Seems to be consistent with the fact that only for commits there =
is
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger
transactions.

browsing the just commited elements opening a new transaction and=20
getting
a new Resource instance, I get around 30 000 objets/sec rate just
iterating thanks to Resource.getAllContents().

Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) their
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.
But the DBStore (which you used) is not that optimized.

* Second case : I built a big model in the database using the =
complex
metamodel. It contains 700 000 elements. The creation went pretty nicely
(I did not measured it exactly as it was launched during a night, but it
seems I got around 100 objects/sec rate in writting as I was writting
every 700 objects.

Sounds not too bad.

Once the model is built the derby database is 222 MB (which - I =
heard -
is not so big for derby).

Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write simple
SQL statements).

Retrieving the distant resource and calling eAllContents() on it, =
I get=20
a
50 Objects/sec rate at best, which mean my eAllContents() call would=20
take
4 hours !

Currently I'm not sure what exactly eAllContents() does do =
(iteration
order and so).
There are several CDO features that can have a major impact on load=20
rates!

- Collections (xrefs and containment) can be loaded lazily. I don't mean
the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).
|*public interface *CDOSession *extends *CDOProtocolSession,
|IContainer<CDOView>
{
*public **int *getReferenceChunkSize();

*public **void *setReferenceChunkSize(*int *referenceChunkSize);|


- Loading collection elements (target objects) can be batched (the
current name is even worse)
|*public interface *CDOView *extends *CDOProtocolView, INotifier
{
*public **int *getLoadRevisionCollectionChunkSize();

*public **void *setLoadRevisionCollectionChunkSize(*int
*loadRevisionCollectionChunkSize);|



- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.
|*public class *CDOViewImpl *extends
|*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
|CDOIDProvider,
Adapter.Internal
{
*public *CDOFeatureAnalyzer getFeatureAnalyzer()
{
*return *featureAnalyzer;
}

*public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
{
*this*.featureAnalyzer =3D featureAnalyzer =3D=3D *null *?
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
}|


- There's a SmartReadAheadThread (if you're curious, please ask Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts
(by design)
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487)
- Maybe others...

Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore.

This is probably linked to the way the mapping to db is done, =
here's the
config I used (came from CDO-server example if I recall correctly).


<repository name=3D"repo1">
<property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
<property name=3D"supportingAudits" value=3D"true"/>
<property name=3D"verifyingRevisions" value=3D"false"/>
<property name=3D"currentLRUCapacity" value=3D"10000"/>

I guess this one could be larger.

<property name=3D"revisedLRUCapacity" =
value=3D"100"/>

<store type=3D"db">
<!-- type: horizontal | vertical | <any
user-contributed type> --> <mappingStrategy
type=3D"horizontal">
<!-- ONE_TABLE_PER_REFERENCE |
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
<property name=3D"toManyReferences"
value=3D"ONE_TABLE_PER_REFERENCE"/>

<!-- LIKE_ATTRIBUTES |
LIKE_TO_MANY_REFERENCES --> <property
name=3D"toOneReferences"
value=3D"LIKE_ATTRIBUTES"/>

<!-- MODEL | STRATEGY -->
<property name=3D"mappingPrecedence"
value=3D"MODEL"/>

This one is obsolete.

</mappingStrategy>

<dbAdapter name=3D"derby-embedded"/>
<dataSource
=
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/>

</store>
</repository>




What do you think about that ? What throughput do you think I should
expect ?
As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with values
from other measures (other setups, properties, etc. or even other
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to grow
slowly ;-)

What are the main reasons fur such figures ?

Hmm, I *suspect* you don't like the figures? I can find no =
evidence your
assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and end-to-end
throughput.
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).

Cheers
/Eike
=20


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<META http-equiv=3DContent-Type =
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<META content=3D"MSHTML 6.00.6000.16608" name=3DGENERATOR></HEAD>
<BODY text=3D#000000 bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Good point Eike,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Cedric,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>How do you create your CDOSessionIMpl=20
?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Are you using your own mechanism =
?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Because it could still occured in the =
case&nbsp;we=20
doesn`t go through <FONT size=3D3>CDOSessionConfigurationImpl =
and</FONT><FONT=20
size=3D2> create directly the CDOSession</FONT></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><FONT =
size=3D2></FONT></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Ex:</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2><FONT size=3D2>CDOSession session =3D=20
CDOSessionImpl();</FONT></FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>By default disablyLegacySystem is=20
false.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>In this case Eike, Do we have something =
else to=20
avoid that ? Maybe I`m not aware of other mechanism.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Simon</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV>"Eike Stepper" &lt;<A=20
href=3D"mailto:stepper@sympedia.de">stepper@sympedia.de</A>&gt; a =
=E9crit dans le=20
message de news: <A=20
href=3D"mailto:483ED9A4.7010302@sympedia.de">483ED9A4.7010302@sympedia.de=
</A>...</DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><BR><BR>Simon=20
McDuff schrieb:=20
<BLOCKQUOTE cite=3Dmid:g1ml62$a15$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Did you disable the following :
CDOSessionConfigurationImpl.setLegacySupportEnabled(true);

before opening your session ?

This could cause what you are observing ?

If your classes are generating with CDOObjectImpl as the super class, =
you=20
can disableLegacySupport by putting it at true.
</PRE></BLOCKQUOTE>Good point in general!<BR><BR>But I added some =
logic some=20
time ago that ensures that *session legacy support* can only be =
enabled if the=20
*legacy system* is available in general:<BR><BR>
<STYLE type=3Dtext/css>CODE {
FONT-SIZE: 10pt; MARGIN: 0px; FONT-FAMILY: Courier New, Courier
}
</STYLE>
<!-- =
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
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converted code =3D --><!-- =3D Java2Html Converter 5.0 [2006-02-26] by =
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<DIV class=3Djava align=3Dleft>
<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff border=3D0>
<TBODY>
<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setDisableLegacyObjects</FONT><FONT=20
color=3D#000000>(</FONT><FONT=20
color=3D#7f0055><B>boolean&nbsp;</B></FONT><FONT=20
color=3D#000000>disableLegacyObjects</FONT><FONT=20
color=3D#000000>)</FONT><BR><FONT =
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#000000>checkInactive</FONT><FONT =
color=3D#000000>()</FONT><FONT=20
color=3D#000000>;</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>if&nbsp;</B></FONT><FONT =
color=3D#000000>(</FONT><FONT=20
=
color=3D#000000> !disableLegacyObjects&nbsp;&amp;&amp;&nbsp;! FSMUtil.isLeg=
acySystemAvailable</FONT><FONT=20
color=3D#000000>())</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </FONT><FONT =

color=3D#7f0055><B>throw&nbsp;new&nbsp;</B></FONT ><FONT=20
color=3D#000000>LegacySystemNotAvailableException</FONT><FONT=20
color=3D#000000>()</FONT><FONT color=3D#000000>;</FONT><BR><FONT =

color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#000000>}</FONT><BR><FONT =
color=3D#ffffff></FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>this</B></FONT><FONT=20
=
color=3D#000000> .disableLegacyObjects&nbsp;=3D&nbsp;disableLegacyObj ects;=
</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT =
color=3D#000000>}</FONT></CODE> </TD><!-- end source code =
--></TR></TBODY></TABLE></DIV><!-- =3D END of automatically =
generated HTML code =3D --><!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D --><BR>Notice=20
that the whole legacy system is currently (since the work on the=20
HibernateStore) broken.<BR>The needed CDOWeaver is currently not part =
of the=20
distro anymore (also due to issues with the build system).<BR><BR>This =

altogether seems to exclude the legacy system as root cause for =
performance=20
degradation.<BR><BR>Cheers<BR>/Eike<BR><BR><BR><BR>
<BLOCKQUOTE cite=3Dmid:g1ml62$a15$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Simon


"C=E9dric Brun" <A class=3Dmoz-txt-link-rfc2396E =
href=3D"mailto:cedric.brun@obeo.fr">&lt;cedric.brun@obeo.fr&gt;</A> a =
=E9crit dans le message de news:=20
<A class=3Dmoz-txt-link-abbreviated =
href=3D"mailto:g1mbhe$2cl$1@build.eclipse.org">g1mbhe$2cl$1@build.eclipse=
..org</A>...
</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">Eike,

As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
relevant, but in the testcase I'm working on (with the complex =
metamodel,
big model in database and 50 o/sec throughput) my profiler says that =
most
of the time (like 99.9%) is spent in a readString call from
CDOClassRefImpl :

public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
IOException
{
// TODO Optimize transfer of URIs
packageURI =3D in.readString();
if (packageURI =3D=3D null)
{
packageURI =3D defaultURI;
}

classifierID =3D in.readInt();
}

The TODO let me think this seems relevant but I'm not sure, what do you
think of it ?

C=E9dric


Eike Stepper wrote:

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">Hi C=E9dric,

That sounds interesting!
Comments inline...


C=E9dric Brun schrieb:
</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex
one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
Features)

The test is a "quick and dirty" one so please do not take these figures
too seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.

</PRE></BLOCKQUOTE><PRE wrap=3D"">Looks like a sign that the NIO =
socket channels are efficient ,-)
You used localhost for TCP transport I guess?

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">* First case : building =
a small model (10000 elements) with the simple
MM, only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.

</PRE></BLOCKQUOTE><PRE wrap=3D"">Seems to be consistent with =
the fact that only for commits there is
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger
transactions.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">browsing the just =
commited elements opening a new transaction and=20
getting
a new Resource instance, I get around 30 000 objets/sec rate just
iterating thanks to Resource.getAllContents().

</PRE></BLOCKQUOTE><PRE wrap=3D"">Hehe, this is a sign that =
client side caching works well:
All views and transactions of a single session share (and cache) their
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.
But the DBStore (which you used) is not that optimized.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">* Second case : I built =
a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely
(I did not measured it exactly as it was launched during a night, but it
seems I got around 100 objects/sec rate in writting as I was writting
every 700 objects.

</PRE></BLOCKQUOTE><PRE wrap=3D"">Sounds not too bad.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">Once the model is built =
the derby database is 222 MB (which - I heard -
is not so big for derby).

</PRE></BLOCKQUOTE><PRE wrap=3D"">Hmm, I have no extensive =
experience with Derby.
To be honest, I'm really no database expert (although I can write simple
SQL statements).

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">Retrieving the distant =
resource and calling eAllContents() on it, I get=20
a
50 Objects/sec rate at best, which mean my eAllContents() call would=20
take
4 hours !

</PRE></BLOCKQUOTE><PRE wrap=3D"">Currently I'm not sure what =
exactly eAllContents() does do (iteration
order and so).
There are several CDO features that can have a major impact on load=20
rates!

- Collections (xrefs and containment) can be loaded lazily. I don't mean
the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).
|*public interface *CDOSession *extends *CDOProtocolSession,
|IContainer&lt;CDOView&gt;
{
*public **int *getReferenceChunkSize();

*public **void *setReferenceChunkSize(*int *referenceChunkSize);|


- Loading collection elements (target objects) can be batched (the
current name is even worse)
|*public interface *CDOView *extends *CDOProtocolView, INotifier
{
*public **int *getLoadRevisionCollectionChunkSize();

*public **void *setLoadRevisionCollectionChunkSize(*int
*loadRevisionCollectionChunkSize);|



- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.
|*public class *CDOViewImpl *extends
|*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
|CDOIDProvider,
Adapter.Internal
{
*public *CDOFeatureAnalyzer getFeatureAnalyzer()
{
*return *featureAnalyzer;
}

*public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
{
*this*.featureAnalyzer =3D featureAnalyzer =3D=3D *null *?
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
}|


- There's a SmartReadAheadThread (if you're curious, please ask Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts
(by design)
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see
<A class=3Dmoz-txt-link-freetext =
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487">https://b=
ugs.eclipse.org/bugs/show_bug.cgi?id=3D214487</A>)
- Maybe others...

Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">This is probably linked =
to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name=3D"repo1"&gt;
&lt;property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name=3D"supportingAudits" =
value=3D"true"/&gt;
&lt;property name=3D"verifyingRevisions" =
value=3D"false"/&gt;
&lt;property name=3D"currentLRUCapacity" =
value=3D"10000"/&gt;

</PRE></BLOCKQUOTE><PRE wrap=3D"">I guess this one could be =
larger.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D""> =
&lt;property name=3D"revisedLRUCapacity" value=3D"100"/&gt;

&lt;store type=3D"db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any
user-contributed type&gt; --&gt; =
&lt;mappingStrategy
type=3D"horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE |
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES =
--&gt;
&lt;property name=3D"toManyReferences"
value=3D"ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES |
LIKE_TO_MANY_REFERENCES --&gt; =
&lt;property
name=3D"toOneReferences"
value=3D"LIKE_ATTRIBUTES"/&gt;

&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name=3D"mappingPrecedence"
value=3D"MODEL"/&gt;

</PRE></BLOCKQUOTE><PRE wrap=3D"">This one is obsolete.

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D""> =
&lt;/mappingStrategy&gt;

&lt;dbAdapter name=3D"derby-embedded"/&gt;
&lt;dataSource
=
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ?
</PRE></BLOCKQUOTE><PRE wrap=3D"">As I said that's very =
difficult to judge.
I believe it's more appropriate to compare the actual values with values
from other measures (other setups, properties, etc. or even other
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to grow
slowly ;-)

</PRE>
<BLOCKQUOTE type=3D"cite"><PRE wrap=3D"">What are the main =
reasons fur such figures ?

</PRE></BLOCKQUOTE><PRE wrap=3D"">Hmm, I *suspect* you don't =
like the figures? I can find no evidence your
assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and end-to-end
throughput.
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).

Cheers
/Eike
</PRE></BLOCKQUOTE></BLOCKQUOTE><PRE wrap=3D""><!---->

</PRE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>

------=_NextPart_000_04D9_01C8C189.41CE2B50--
Re: [CDO] reading/writting throughput performances [message #123729 is a reply to message #123696] Thu, 29 May 2008 16:50 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------020208050506060501030003
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 8bit

Simon McDuff schrieb:
> Good point Eike,
>
> Cedric,
>
> How do you create your CDOSessionIMpl ?
> Are you using your own mechanism ?
>
> Because it could still occured in the case we doesn`t go through
> CDOSessionConfigurationImpl and create directly the CDOSession
You could be right, too. Basically I hate myself because once I
advocated for default legacy support!!! You remember these discussions?
Since several months now I'd really like to change that (and the
checkbox in the OpenSessionDialog is early evidence). I didn't dare to
do it because formerly disableLegacyObjects was a ctor arg and a
semantic change would have broken all clients without compiler warning.
Now that there are no ctor args anymore IO really consider making this
change a late one for Ganymede. Otherwise we'd have to carry this odd
issue for another year and maybe maintain two different versions of the
semantic. What do you think?

>
> Ex:
>
> CDOSession session = CDOSessionImpl();
>
> By default disablyLegacySystem is false.
>
> In this case Eike, Do we have something else to avoid that ? Maybe I`m
> not aware of other mechanism.
I can add the same check to doBeforeActivate(), too.

Cheers
/Eike

>
> Simon
>
> "Eike Stepper" <stepper@sympedia.de <mailto:stepper@sympedia.de>> a
>
Re: [CDO] reading/writting throughput performances [message #123755 is a reply to message #123729] Thu, 29 May 2008 17:11 Go to previous messageGo to next message
Mark Geib is currently offline Mark GeibFriend
Messages: 432
Registered: July 2009
Senior Member
I would vote to make the change. You will be sorry if you miss this
opportunity. The users can handle the change I think.

Just my thoughts,
Mark.



Eike Stepper wrote:
> Simon McDuff schrieb:
>> Good point Eike,
>>
>> Cedric,
>>
>> How do you create your CDOSessionIMpl ?
>> Are you using your own mechanism ?
>>
>> Because it could still occured in the case we doesn`t go through
>> CDOSessionConfigurationImpl and create directly the CDOSession
> You could be right, too. Basically I hate myself because once I
> advocated for default legacy support!!! You remember these discussions?
> Since several months now I'd really like to change that (and the
> checkbox in the OpenSessionDialog is early evidence). I didn't dare to
> do it because formerly disableLegacyObjects was a ctor arg and a
> semantic change would have broken all clients without compiler warning.
> Now that there are no ctor args anymore IO really consider making this
> change a late one for Ganymede. Otherwise we'd have to carry this odd
> issue for another year and maybe maintain two different versions of the
> semantic. What do you think?
>
>>
>> Ex:
>>
>> CDOSession session = CDOSessionImpl();
>>
>> By default disablyLegacySystem is false.
>>
>> In this case Eike, Do we have something else to avoid that ? Maybe I`m
>> not aware of other mechanism.
> I can add the same check to doBeforeActivate(), too.
>
> Cheers
> /Eike
>
>>
>> Simon
>>
>> "Eike Stepper" <stepper@sympedia.de <mailto:stepper@sympedia.de>> a
>> écrit dans le message de news: 483ED9A4.7010302@sympedia.de
>> <mailto:483ED9A4.7010302@sympedia.de>...
>>
>>
>>
>> Simon McDuff schrieb:
>>> Did you disable the following :
>>> CDOSessionConfigurationImpl.setLegacySupportEnabled(true);
>>>
>>> before opening your session ?
>>>
>>> This could cause what you are observing ?
>>>
>>> If your classes are generating with CDOObjectImpl as the super class, you
>>> can disableLegacySupport by putting it at true.
>>>
>> Good point in general!
>>
>> But I added some logic some time ago that ensures that *session
>> legacy support* can only be enabled if the *legacy system* is
>> available in general:
>>
>> | *public **void *setDisableLegacyObjects(*boolean *disableLegacyObjects)
>> {
>> checkInactive();
>> *if *(!disableLegacyObjects && !FSMUtil.isLegacySystemAvailable())
>> {
>> *throw new *LegacySystemNotAvailableException();
>> }
>>
>> *this*.disableLegacyObjects = disableLegacyObjects;
>> }|
>>
>>
>> Notice that the whole legacy system is currently (since the work
>> on the HibernateStore) broken.
>> The needed CDOWeaver is currently not part of the distro anymore
>> (also due to issues with the build system).
>>
>> This altogether seems to exclude the legacy system as root cause
>> for performance degradation.
>>
>> Cheers
>> /Eike
>>
>>
>>
>>> Simon
>>>
>>>
>>> "Cédric Brun" <cedric.brun@obeo.fr> a écrit dans le message de news:
>>> g1mbhe$2cl$1@build.eclipse..org...
>>>
>>>> Eike,
>>>>
>>>> As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
>>>> relevant, but in the testcase I'm working on (with the complex metamodel,
>>>> big model in database and 50 o/sec throughput) my profiler says that most
>>>> of the time (like 99.9%) is spent in a readString call from
>>>> CDOClassRefImpl :
>>>>
>>>> public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
>>>> IOException
>>>> {
>>>> // TODO Optimize transfer of URIs
>>>> packageURI = in.readString();
>>>> if (packageURI == null)
>>>> {
>>>> packageURI = defaultURI;
>>>> }
>>>>
>>>> classifierID = in.readInt();
>>>> }
>>>>
>>>> The TODO let me think this seems relevant but I'm not sure, what do you
>>>> think of it ?
>>>>
>>>> Cédric
>>>>
>>>>
>>>> Eike Stepper wrote:
>>>>
>>>>
>>>>> Hi Cédric,
>>>>>
>>>>> That sounds interesting!
>>>>> Comments inline...
>>>>>
>>>>>
>>>>> Cédric Brun schrieb:
>>>>>
>>>>>> Hi Eike,
>>>>>>
>>>>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>>>>> measuring read/write throughput when I use CDO (RC2).
>>>>>>
>>>>>> I'm using an embeded-derby database, two different metamodels (complex
>>>>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>>>>> Features)
>>>>>>
>>>>>> The test is a "quick and dirty" one so please do not take these figures
>>>>>> too seriously, I would just like to have your input about the "order of
>>>>>> magnitude" I should expect or settings affecting seriously these
>>>>>> performances. I tried both JVM and TCP acceptor but the performances are
>>>>>> quite similar though JVM is a bit faster.
>>>>>>
>>>>>>
>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>> You used localhost for TCP transport I guess?
>>>>>
>>>>>
>>>>>> * First case : building a small model (10000 elements) with the simple
>>>>>> MM, only adding instances in an empty database :
>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>>>>
>>>>>>
>>>>> Seems to be consistent with the fact that only for commits there is
>>>>> remote traffic.
>>>>> And the backend transaction management is another overhead.
>>>>> So the impact of the number objects/commit starts with bigger
>>>>> transactions.
>>>>>
>>>>>
>>>>>> browsing the just commited elements opening a new transaction and
>>>>>> getting
>>>>>> a new Resource instance, I get around 30 000 objets/sec rate just
>>>>>> iterating thanks to Resource.getAllContents().
>>>>>>
>>>>>>
>>>>> Hehe, this is a sign that client side caching works well:
>>>>> All views and transactions of a single session share (and cache) their
>>>>> object state.
>>>>> Otherwise I'd expect much smaller values.
>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
>>>>> several thousands objects/sec.
>>>>> But the DBStore (which you used) is not that optimized.
>>>>>
>>>>>
>>>>>> * Second case : I built a big model in the database using the complex
>>>>>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>>>>>> (I did not measured it exactly as it was launched during a night, but it
>>>>>> seems I got around 100 objects/sec rate in writting as I was writting
>>>>>> every 700 objects.
>>>>>>
>>>>>>
>>>>> Sounds not too bad.
>>>>>
>>>>>
>>>>>> Once the model is built the derby database is 222 MB (which - I heard -
>>>>>> is not so big for derby).
>>>>>>
>>>>>>
>>>>> Hmm, I have no extensive experience with Derby.
>>>>> To be honest, I'm really no database expert (although I can write simple
>>>>> SQL statements).
>>>>>
>>>>>
>>>>>> Retrieving the distant resource and calling eAllContents() on it, I get
>>>>>> a
>>>>>> 50 Objects/sec rate at best, which mean my eAllContents() call would
>>>>>> take
>>>>>> 4 hours !
>>>>>>
>>>>>>
>>>>> Currently I'm not sure what exactly eAllContents() does do (iteration
>>>>> order and so).
>>>>> There are several CDO features that can have a major impact on load
>>>>> rates!
>>>>>
>>>>> - Collections (xrefs and containment) can be loaded lazily. I don't mean
>>>>> the target objects, which are lazy by default anyway, but even the
>>>>> target IDs that are in the collections. We call that "reference
>>>>> chunking" (but search for a better name is ongoing).
>>>>> |*public interface *CDOSession *extends *CDOProtocolSession,
>>>>> |IContainer<CDOView>
>>>>> {
>>>>> *public **int *getReferenceChunkSize();
>>>>>
>>>>> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>>>>>
>>>>>
>>>>> - Loading collection elements (target objects) can be batched (the
>>>>> current name is even worse)
>>>>> |*public interface *CDOView *extends *CDOProtocolView, INotifier
>>>>> {
>>>>> *public **int *getLoadRevisionCollectionChunkSize();
>>>>>
>>>>> *public **void *setLoadRevisionCollectionChunkSize(*int
>>>>> *loadRevisionCollectionChunkSize);|
>>>>>
>>>>>
>>>>>
>>>>> - One of the most sophisticated feature is automatic model usage
>>>>> analyzation. The result are fetch rules that are sent to the server.
>>>>> When later objects are loaded from the server, it can answer with
>>>>> additional objects that are likely to be needed by the client in the
>>>>> near future.
>>>>> |*public class *CDOViewImpl *extends
>>>>> |*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
>>>>> |CDOIDProvider,
>>>>> Adapter.Internal
>>>>> {
>>>>> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>> {
>>>>> *return *featureAnalyzer;
>>>>> }
>>>>>
>>>>> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
>>>>> {
>>>>> *this*.featureAnalyzer = featureAnalyzer == *null *?
>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>> }|
>>>>>
>>>>>
>>>>> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
>>>>> - Caches can be configured
>>>>> - ...
>>>>>
>>>>>
>>>>> Known issues of the DBStore:
>>>>> - When in auditing mode updates are always written as complete inserts
>>>>> (by design)
>>>>> - When configuring toManyReferences to a value different from
>>>>> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
>>>>> - No (few) prepared statements are used (see
>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
>>>>> - Maybe others...
>>>>>
>>>>> Please note that the DBStore was not written by me to compete with
>>>>> Hibernate in terms of performance or mapping capabilities.
>>>>> Now that Martin and I, well in the end mostly Martin, provide a
>>>>> HibernateStore and this HibernateStore gets more and more features I
>>>>> expect that there will be a trend away from the DBStore.
>>>>>
>>>>>
>>>>>> This is probably linked to the way the mapping to db is done, here's the
>>>>>> config I used (came from CDO-server example if I recall correctly).
>>>>>>
>>>>>>
>>>>>> <repository name="repo1">
>>>>>> <property name="overrideUUID"
>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>> <property name="supportingAudits" value="true"/>
>>>>>> <property name="verifyingRevisions" value="false"/>
>>>>>> <property name="currentLRUCapacity" value="10000"/>
>>>>>>
>>>>>>
>>>>> I guess this one could be larger.
>>>>>
>>>>>
>>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>>
>>>>>> <store type="db">
>>>>>> <!-- type: horizontal | vertical | <any
>>>>>> user-contributed type> --> <mappingStrategy
>>>>>> type="horizontal">
>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>> ONE_TABLE_PER_CLASS |
>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>>>>> <property name="toManyReferences"
>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>
>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>> LIKE_TO_MANY_REFERENCES --> <property
>>>>>> name="toOneReferences"
>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>
>>>>>> <!-- MODEL | STRATEGY -->
>>>>>> <property name="mappingPrecedence"
>>>>>> value="MODEL"/>
>>>>>>
>>>>>>
>>>>> This one is obsolete.
>>>>>
>>>>>
>>>>>> </mappingStrategy>
>>>>>>
>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>> <dataSource
>>>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>> databaseName="/tmp/cdodb1"
>>>>>> createDatabase="create"/>
>>>>>>
>>>>>> </store>
>>>>>> </repository>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> What do you think about that ? What throughput do you think I should
>>>>>> expect ?
>>>>>>
>>>>> As I said that's very difficult to judge.
>>>>> I believe it's more appropriate to compare the actual values with values
>>>>> from other measures (other setups, properties, etc. or even other
>>>>> products) instead of random expectations.
>>>>> Apologies that I didn't have the time so far to provide some reference
>>>>> measures myself. Maybe this gets better now that the team starts to grow
>>>>> slowly ;-)
>>>>>
>>>>>
>>>>>> What are the main reasons fur such figures ?
>>>>>>
>>>>>>
>>>>> Hmm, I *suspect* you don't like the figures? I can find no evidence your
>>>>> assessment ;-)
>>>>>
>>>>> Ahh,one more note:
>>>>> Tracing can also have a significant impact on performance and end-to-end
>>>>> throughput.
>>>>> Turn it off by all means. And please make sure that it's really turned
>>>>> off, not only invisible (i.e. console is not a target).
>>>>>
>>>>> Cheers
>>>>> /Eike
>>>>>
>>>
>>>
>>>
>>
Re: [CDO] reading/writting throughput performances [message #123770 is a reply to message #123755] Thu, 29 May 2008 17:13 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

Mark,

Thank you to encourage me ;-)
RC3 will have the change.

Cheers
/Eike



Mark Geib schrieb:
> I would vote to make the change. You will be sorry if you miss this
> opportunity. The users can handle the change I think.
>
> Just my thoughts,
> Mark.
>
>
>
> Eike Stepper wrote:
>> Simon McDuff schrieb:
>>> Good point Eike,
>>>
>>> Cedric,
>>>
>>> How do you create your CDOSessionIMpl ?
>>> Are you using your own mechanism ?
>>>
>>> Because it could still occured in the case we doesn`t go through
>>> CDOSessionConfigurationImpl and create directly the CDOSession
>> You could be right, too. Basically I hate myself because once I
>> advocated for default legacy support!!! You remember these
>> discussions? Since several months now I'd really like to change that
>> (and the checkbox in the OpenSessionDialog is early evidence). I
>> didn't dare to do it because formerly disableLegacyObjects was a ctor
>> arg and a semantic change would have broken all clients without
>> compiler warning. Now that there are no ctor args anymore IO really
>> consider making this change a late one for Ganymede. Otherwise we'd
>> have to carry this odd issue for another year and maybe maintain two
>> different versions of the semantic. What do you think?
>>
>>>
>>> Ex:
>>>
>>> CDOSession session = CDOSessionImpl();
>>>
>>> By default disablyLegacySystem is false.
>>>
>>> In this case Eike, Do we have something else to avoid that ? Maybe
>>> I`m not aware of other mechanism.
>> I can add the same check to doBeforeActivate(), too.
>>
>> Cheers
>> /Eike
>>
>>>
>>> Simon
>>>
>>> "Eike Stepper" <stepper@sympedia.de <mailto:stepper@sympedia.de>> a
>>> écrit dans le message de news: 483ED9A4.7010302@sympedia.de
>>> <mailto:483ED9A4.7010302@sympedia.de>...
>>>
>>>
>>>
>>> Simon McDuff schrieb:
>>>> Did you disable the following :
>>>> CDOSessionConfigurationImpl.setLegacySupportEnabled(true);
>>>>
>>>> before opening your session ?
>>>>
>>>> This could cause what you are observing ?
>>>>
>>>> If your classes are generating with CDOObjectImpl as the super
>>>> class, you can disableLegacySupport by putting it at true.
>>>>
>>> Good point in general!
>>>
>>> But I added some logic some time ago that ensures that *session
>>> legacy support* can only be enabled if the *legacy system* is
>>> available in general:
>>>
>>> | *public **void *setDisableLegacyObjects(*boolean
>>> *disableLegacyObjects)
>>> {
>>> checkInactive();
>>> *if *(!disableLegacyObjects &&
>>> !FSMUtil.isLegacySystemAvailable())
>>> {
>>> *throw new *LegacySystemNotAvailableException();
>>> }
>>>
>>> *this*.disableLegacyObjects = disableLegacyObjects;
>>> }|
>>>
>>>
>>> Notice that the whole legacy system is currently (since the work
>>> on the HibernateStore) broken.
>>> The needed CDOWeaver is currently not part of the distro anymore
>>> (also due to issues with the build system).
>>>
>>> This altogether seems to exclude the legacy system as root cause
>>> for performance degradation.
>>>
>>> Cheers
>>> /Eike
>>>
>>>
>>>
>>>> Simon
>>>>
>>>>
>>>> "Cédric Brun" <cedric.brun@obeo.fr> a écrit dans le message de
>>>> news: g1mbhe$2cl$1@build.eclipse..org...
>>>>
>>>>> Eike,
>>>>>
>>>>> As I don't know (yet ;) ) all the internals of CDO I'm not
>>>>> sure this is
>>>>> relevant, but in the testcase I'm working on (with the complex
>>>>> metamodel,
>>>>> big model in database and 50 o/sec throughput) my profiler
>>>>> says that most
>>>>> of the time (like 99.9%) is spent in a readString call from
>>>>> CDOClassRefImpl :
>>>>>
>>>>> public CDOClassRefImpl(ExtendedDataInput in, String
>>>>> defaultURI) throws
>>>>> IOException
>>>>> {
>>>>> // TODO Optimize transfer of URIs
>>>>> packageURI = in.readString();
>>>>> if (packageURI == null)
>>>>> {
>>>>> packageURI = defaultURI;
>>>>> }
>>>>>
>>>>> classifierID = in.readInt();
>>>>> }
>>>>>
>>>>> The TODO let me think this seems relevant but I'm not sure,
>>>>> what do you
>>>>> think of it ?
>>>>>
>>>>> Cédric
>>>>>
>>>>>
>>>>> Eike Stepper wrote:
>>>>>
>>>>>
>>>>>> Hi Cédric,
>>>>>>
>>>>>> That sounds interesting!
>>>>>> Comments inline...
>>>>>>
>>>>>>
>>>>>> Cédric Brun schrieb:
>>>>>>
>>>>>>> Hi Eike,
>>>>>>>
>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>> unit-tests
>>>>>>> measuring read/write throughput when I use CDO (RC2).
>>>>>>>
>>>>>>> I'm using an embeded-derby database, two different
>>>>>>> metamodels (complex
>>>>>>> one - 250 EClassifiers/300 features and a simple one - 1
>>>>>>> Classifier/3
>>>>>>> Features)
>>>>>>>
>>>>>>> The test is a "quick and dirty" one so please do not take
>>>>>>> these figures
>>>>>>> too seriously, I would just like to have your input about
>>>>>>> the "order of
>>>>>>> magnitude" I should expect or settings affecting seriously
>>>>>>> these
>>>>>>> performances. I tried both JVM and TCP acceptor but the
>>>>>>> performances are
>>>>>>> quite similar though JVM is a bit faster.
>>>>>>>
>>>>>>>
>>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>>> You used localhost for TCP transport I guess?
>>>>>>
>>>>>>
>>>>>>> * First case : building a small model (10000 elements) with
>>>>>>> the simple
>>>>>>> MM, only adding instances in an empty database :
>>>>>>> commiting change on every add I get a 2 objects per second
>>>>>>> rate.
>>>>>>> commiting changes every 10 adds - I get a 30 objects per
>>>>>>> second rate.
>>>>>>>
>>>>>>>
>>>>>> Seems to be consistent with the fact that only for commits
>>>>>> there is
>>>>>> remote traffic.
>>>>>> And the backend transaction management is another overhead.
>>>>>> So the impact of the number objects/commit starts with bigger
>>>>>> transactions.
>>>>>>
>>>>>>
>>>>>>> browsing the just commited elements opening a new
>>>>>>> transaction and getting
>>>>>>> a new Resource instance, I get around 30 000 objets/sec rate
>>>>>>> just
>>>>>>> iterating thanks to Resource.getAllContents().
>>>>>>>
>>>>>>>
>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>> All views and transactions of a single session share (and
>>>>>> cache) their
>>>>>> object state.
>>>>>> Otherwise I'd expect much smaller values.
>>>>>> With his ObjectivityStore implementation Simon (cc'ed)
>>>>>> reached rates of
>>>>>> several thousands objects/sec.
>>>>>> But the DBStore (which you used) is not that optimized.
>>>>>>
>>>>>>
>>>>>>> * Second case : I built a big model in the database using
>>>>>>> the complex
>>>>>>> metamodel. It contains 700 000 elements. The creation went
>>>>>>> pretty nicely
>>>>>>> (I did not measured it exactly as it was launched during a
>>>>>>> night, but it
>>>>>>> seems I got around 100 objects/sec rate in writting as I was
>>>>>>> writting
>>>>>>> every 700 objects.
>>>>>>>
>>>>>>>
>>>>>> Sounds not too bad.
>>>>>>
>>>>>>
>>>>>>> Once the model is built the derby database is 222 MB (which
>>>>>>> - I heard -
>>>>>>> is not so big for derby).
>>>>>>>
>>>>>>>
>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>> To be honest, I'm really no database expert (although I can
>>>>>> write simple
>>>>>> SQL statements).
>>>>>>
>>>>>>
>>>>>>> Retrieving the distant resource and calling eAllContents()
>>>>>>> on it, I get a
>>>>>>> 50 Objects/sec rate at best, which mean my eAllContents()
>>>>>>> call would take
>>>>>>> 4 hours !
>>>>>>>
>>>>>>>
>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>> (iteration
>>>>>> order and so).
>>>>>> There are several CDO features that can have a major impact
>>>>>> on load rates!
>>>>>>
>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>> don't mean
>>>>>> the target objects, which are lazy by default anyway, but
>>>>>> even the
>>>>>> target IDs that are in the collections. We call that "reference
>>>>>> chunking" (but search for a better name is ongoing).
>>>>>> |*public interface *CDOSession *extends *CDOProtocolSession,
>>>>>> |IContainer<CDOView>
>>>>>> {
>>>>>> *public **int *getReferenceChunkSize();
>>>>>>
>>>>>> *public **void *setReferenceChunkSize(*int
>>>>>> *referenceChunkSize);|
>>>>>>
>>>>>>
>>>>>> - Loading collection elements (target objects) can be batched
>>>>>> (the
>>>>>> current name is even worse)
>>>>>> |*public interface *CDOView *extends *CDOProtocolView, INotifier
>>>>>> {
>>>>>> *public **int *getLoadRevisionCollectionChunkSize();
>>>>>>
>>>>>> *public **void *setLoadRevisionCollectionChunkSize(*int
>>>>>> *loadRevisionCollectionChunkSize);|
>>>>>>
>>>>>>
>>>>>>
>>>>>> - One of the most sophisticated feature is automatic model usage
>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>> server.
>>>>>> When later objects are loaded from the server, it can answer
>>>>>> with
>>>>>> additional objects that are likely to be needed by the client
>>>>>> in the
>>>>>> near future.
>>>>>> |*public class *CDOViewImpl *extends
>>>>>> |*org.eclipse.net4j.internal.util.event.Notifier *implements
>>>>>> *CDOView,
>>>>>> |CDOIDProvider,
>>>>>> Adapter.Internal
>>>>>> {
>>>>>> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>> {
>>>>>> *return *featureAnalyzer;
>>>>>> }
>>>>>>
>>>>>> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>> featureAnalyzer)
>>>>>> {
>>>>>> *this*.featureAnalyzer = featureAnalyzer == *null *?
>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>> }|
>>>>>>
>>>>>>
>>>>>> - There's a SmartReadAheadThread (if you're curious, please
>>>>>> ask Simon).
>>>>>> - Caches can be configured
>>>>>> - ...
>>>>>>
>>>>>>
>>>>>> Known issues of the DBStore:
>>>>>> - When in auditing mode updates are always written as
>>>>>> complete inserts
>>>>>> (by design)
>>>>>> - When configuring toManyReferences to a value different from
>>>>>> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
>>>>>> - No (few) prepared statements are used (see
>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
>>>>>> - Maybe others...
>>>>>>
>>>>>> Please note that the DBStore was not written by me to compete
>>>>>> with
>>>>>> Hibernate in terms of performance or mapping capabilities.
>>>>>> Now that Martin and I, well in the end mostly Martin, provide a
>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>> features I
>>>>>> expect that there will be a trend away from the DBStore.
>>>>>>
>>>>>>
>>>>>>> This is probably linked to the way the mapping to db is
>>>>>>> done, here's the
>>>>>>> config I used (came from CDO-server example if I recall
>>>>>>> correctly).
>>>>>>>
>>>>>>>
>>>>>>> <repository name="repo1">
>>>>>>> <property name="overrideUUID"
>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>> <property name="supportingAudits"
>>>>>>> value="true"/>
>>>>>>> <property name="verifyingRevisions"
>>>>>>> value="false"/>
>>>>>>> <property name="currentLRUCapacity"
>>>>>>> value="10000"/>
>>>>>>>
>>>>>>>
>>>>>> I guess this one could be larger.
>>>>>>
>>>>>>
>>>>>>> <property name="revisedLRUCapacity"
>>>>>>> value="100"/>
>>>>>>>
>>>>>>> <store type="db">
>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>> user-contributed type> -->
>>>>>>> <mappingStrategy
>>>>>>> type="horizontal">
>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>> LIKE_ATTRIBUTES -->
>>>>>>> <property
>>>>>>> name="toManyReferences"
>>>>>>>
>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>
>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>> <property
>>>>>>> name="toOneReferences"
>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>
>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>> <property
>>>>>>> name="mappingPrecedence"
>>>>>>> value="MODEL"/>
>>>>>>>
>>>>>>>
>>>>>> This one is obsolete.
>>>>>>
>>>>>>
>>>>>>> </mappingStrategy>
>>>>>>>
>>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>>> <dataSource
>>>>>>>
>>>>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>> createDatabase="create"/>
>>>>>>>
>>>>>>> </store>
>>>>>>> </repository>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> What do you think about that ? What throughput do you think
>>>>>>> I should
>>>>>>> expect ?
>>>>>>>
>>>>>> As I said that's very difficult to judge.
>>>>>> I believe it's more appropriate to compare the actual values
>>>>>> with values
>>>>>> from other measures (other setups, properties, etc. or even
>>>>>> other
>>>>>> products) instead of random expectations.
>>>>>> Apologies that I didn't have the time so far to provide some
>>>>>> reference
>>>>>> measures myself. Maybe this gets better now that the team
>>>>>> starts to grow
>>>>>> slowly ;-)
>>>>>>
>>>>>>
>>>>>>> What are the main reasons fur such figures ?
>>>>>>>
>>>>>>>
>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>> evidence your
>>>>>> assessment ;-)
>>>>>>
>>>>>> Ahh,one more note:
>>>>>> Tracing can also have a significant impact on performance and
>>>>>> end-to-end
>>>>>> throughput.
>>>>>> Turn it off by all means. And please make sure that it's
>>>>>> really turned
>>>>>> off, not only invisible (i.e. console is not a target).
>>>>>>
>>>>>> Cheers
>>>>>> /Eike
>>>>>>
>>>>
>>>>
>>>>
>>>
Re: [CDO] reading/writting throughput performances [message #123787 is a reply to message #123651] Thu, 29 May 2008 17:27 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------050305010008090907040306
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Guys,

Comments inline...


Simon McDuff schrieb:
> We noticed a performance degradation in the following case:
>
> When we fetch a collection of objects that contains collections that
> we don't want to use.
> Ex:
>
> Model:
>
> ClassB
> {
> int foo1;
> List childrens1;
> List childrens2;
> List childrens3;
> };
>
> Code:
>
> Resource.contents contains objects of type ClassB.
>
> By fetching instances of classB, we will also fetched some items in
> the list(childrens1, childrens2, childrens3) The problem we had.. is
> we do not know if we want to use it. SO better not to download them.
>
> So In our production(we used our own IStore), we never download any
> objects from collection.
> I'm working at the moment to put in place all feature we used in the
> current CDO.
> That one will be part of
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
> with,CDORevisionImpl needs to supports list that are 0 even if
> referenceChunkSize == 0.
>
> It is true that we obtain good performance.
> Worst case :
> 1500 objects /sec (Real fetch from disk. Page that contains the
> objects, wasn't in the cache of the filesystem.)
>
> Best case
> 12 000 objects/Sec (Fetch objects that are already in the case of the
> filesystem)
>
> (These statistics always fetch objects from server to client. The
> cache client isn't used)
>
> We have another optimization one with SmartReadAhead but for now only
> work for UI client. (for now) This is something we will integrate as
> well in CDO. But for now we concentrate on the other things.
>
> I used an Object database. Based on my preliminary test without CDO.
> I compare
>
> Hibernate vs Objectivity/EMF :
> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>
> The worst.. you will get 30 to 240 objects/sec or
> the best... you will get 500 to 4000 objects/sec
>
> Based on your comments... you are getting the worst (with Derby)!! :-)
And with the DBStore!!
I'd really like to encourage you to use the HibernateStore.
It is much younger than the DBStore but Hibernate itself should do a
much better job on mapping than the DBStore.

That said, the DBStore will, for multiple reasons, never cease to exist
in CDO.

>
>
> Another comments about insertion.
>
> We found another problem when we insert data(DOn't know if it is still
> true). Resource.Contents is a unique list. Basically each time we
> insert one element, it needs to fetch all the collection to see if we
> already have this element. Basically.. it is time consuming. In our
> case we are not going through this stage to persist our objects... but
> the objects are not accessible through that list.
I was not aware of this. Sounds as if we should offer an alternative
implementation for Resource.Contents.
Could you please open a Bugzilla to discuss/track this?

>
>
>
> If speed is an issue for you!! We (You included :-)) can optimize it.
> What I like is Eike did a really good job doing that framwork and
> optimizations are easy to add.
> Also you can change your back-end without affecting you client side.
> (Maybe going to an Object database!!)
> THis was one of the purpose of CDO!! :-)
Thank you ;-)
Indeed, CDO was intended to focus of the protocol aspects, the
repository and the client side addition to the EMF concepts.
I feel that this will become clearer the more IStore implementations we
get that depend on mature 3rd party code for the mapping part.

Cheers
/Eike


>
>
> Simon
>
> "Eike Stepper" <stepper@sympedia.de <mailto:stepper@sympedia.de>>
> a écrit dans le message de news: 483E9332.6050800@sympedia.de
> <mailto:483E9332.6050800@sympedia.de>...
> Hi Cédric,
>
> That sounds interesting!
> Comments inline...
>
>
> Cédric Brun schrieb:
>> Hi Eike,
>>
>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>> measuring read/write throughput when I use CDO (RC2).
>>
>> I'm using an embeded-derby database, two different metamodels (complex one -
>> 250 EClassifiers/300 features and a simple one - 1 Classifier/3 Features)
>>
>> The test is a "quick and dirty" one so please do not take these figures too
>> seriously, I would just like to have your input about the "order of
>> magnitude" I should expect or settings affecting seriously these
>> performances. I tried both JVM and TCP acceptor but the performances are
>> quite similar though JVM is a bit faster.
>>
> Looks like a sign that the NIO socket channels are efficient ,-)
> You used localhost for TCP transport I guess?
>
>> * First case : building a small model (10000 elements) with the simple MM,
>> only adding instances in an empty database :
>> commiting change on every add I get a 2 objects per second rate.
>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>
> Seems to be consistent with the fact that only for commits there
> is remote traffic.
> And the backend transaction management is another overhead.
> So the impact of the number objects/commit starts with bigger
> transactions.
>
>> browsing the just commited elements opening a new transaction and getting a
>> new Resource instance, I get around 30 000 objets/sec rate just iterating
>> thanks to Resource.getAllContents().
>>
> Hehe, this is a sign that client side caching works well:
> All views and transactions of a single session share (and cache)
> their object state.
> Otherwise I'd expect much smaller values.
> With his ObjectivityStore implementation Simon (cc'ed) reached
> rates of several thousands objects/sec.
> But the DBStore (which you used) is not that optimized.
>
>> * Second case : I built a big model in the database using the complex
>> metamodel. It contains 700 000 elements. The creation went pretty nicely (I
>> did not measured it exactly as it was launched during a night, but it seems
>> I got around 100 objects/sec rate in writting as I was writting every 700
>> objects.
>>
> Sounds not too bad.
>
>> Once the model is built the derby database is 222 MB (which - I heard - is
>> not so big for derby).
>>
> Hmm, I have no extensive experience with Derby.
> To be honest, I'm really no database expert (although I can write
> simple SQL statements).
>
>> Retrieving the distant resource and calling eAllContents() on it, I get a 50
>> Objects/sec rate at best, which mean my eAllContents() call would take 4
>> hours !
>>
> Currently I'm not sure what exactly eAllContents() does do
> (iteration order and so).
> There are several CDO features that can have a major impact on
> load rates!
>
> - Collections (xrefs and containment) can be loaded lazily. I
> don't mean the target objects, which are lazy by default anyway,
> but even the target IDs that are in the collections. We call that
> "reference chunking" (but search for a better name is ongoing).
> |*public interface *CDOSession *extends *CDOProtocolSession, IContainer<CDOView>
> {
> *public **int *getReferenceChunkSize();
>
> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>
>
> - Loading collection elements (target objects) can be batched (the
> current name is even worse)
> |*public interface *CDOView *extends *CDOProtocolView, INotifier
> {
> *public **int *getLoadRevisionCollectionChunkSize();
>
> *public **void *setLoadRevisionCollectionChunkSize(*int *loadRevisionCollectionChunkSize);|
>
>
>
> - One of the most sophisticated feature is automatic model usage
> analyzation. The result are fetch rules that are sent to the
> server. When later objects are loaded from the server, it can
> answer with additional objects that are likely to be needed by the
> client in the near future.
> |*public class *CDOViewImpl *extends *org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView, CDOIDProvider,
> Adapter.Internal
> {
> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
> {
> *return *featureAnalyzer;
> }
>
> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
> {
> *this*.featureAnalyzer = featureAnalyzer == *null *? CDOFeatureAnalyzer.NOOP : featureAnalyzer;
> }|
>
>
> - There's a SmartReadAheadThread (if you're curious, please ask
> Simon).
> - Caches can be configured
> - ...
>
>
> Known issues of the DBStore:
> - When in auditing mode updates are always written as complete
> inserts (by design)
> - When configuring toManyReferences to a value different from
> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
> - No (few) prepared statements are used (see
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
> - Maybe others...
>
> Please note that the DBStore was not written by me to compete with
> Hibernate in terms of performance or mapping capabilities.
> Now that Martin and I, well in the end mostly Martin, provide a
> HibernateStore and this HibernateStore gets more and more features
> I expect that there will be a trend away from the DBStore.
>
>> This is probably linked to the way the mapping to db is done, here's the
>> config I used (came from CDO-server example if I recall correctly).
>>
>>
>> <repository name="repo1">
>> <property name="overrideUUID"
>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>> <property name="supportingAudits" value="true"/>
>> <property name="verifyingRevisions" value="false"/>
>> <property name="currentLRUCapacity" value="10000"/>
>>
> I guess this one could be larger.
>
>> <property name="revisedLRUCapacity" value="100"/>
>>
>> <store type="db">
>> <!-- type: horizontal | vertical | <any user-contributed type> -->
>> <mappingStrategy type="horizontal">
>> <!-- ONE_TABLE_PER_REFERENCE | ONE_TABLE_PER_CLASS |
>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>> <property name="toManyReferences" value="ONE_TABLE_PER_REFERENCE"/>
>>
>> <!-- LIKE_ATTRIBUTES | LIKE_TO_MANY_REFERENCES -->
>> <property name="toOneReferences" value="LIKE_ATTRIBUTES"/>
>>
>> <!-- MODEL | STRATEGY -->
>> <property name="mappingPrecedence" value="MODEL"/>
>>
> This one is obsolete.
>
>> </mappingStrategy>
>>
>> <dbAdapter name="derby-embedded"/>
>> <dataSource class="org.apache.derby.jdbc.EmbeddedDataSource"
>> databaseName="/tmp/cdodb1"
>> createDatabase="create"/>
>>
>> </store>
>> </repository>
>>
>>
>>
>>
>> What do you think about that ? What throughput do you think I should
>> expect ?
> As I said that's very difficult to judge.
> I believe it's more appropriate to compare the actual values with
> values from other measures (other setups, properties, etc. or even
> other products) instead of random expectations.
> Apologies that I didn't have the time so far to provide some
> reference measures myself. Maybe this gets better now that the
> team starts to grow slowly ;-)
>
>> What are the main reasons fur such figures ?
>>
> Hmm, I *suspect* you don't like the figures? I can find no
> evidence your assessment ;-)
>
> Ahh,one more note:
> Tracing can also have a significant impact on performance and
> end-to-end throughput.
> Turn it off by all means. And please make sure that it's really
> turned off, not only invisible (i.e. console is not a target).
>
> Cheers
> /Eike
>
>

--------------050305010008090907040306
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Guys,<br>
<br>
Comments inline...<br>
<br>
<br>
Simon McDuff schrieb:
<blockquote cite="mid:g1mkji$h5d$1@build.eclipse.org" type="cite">
<title></title>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<meta content="MSHTML 6.00.6000.16608" name="GENERATOR">
<div>We noticed a performance degradation in the following case:<br>
 <br>
When we fetch a collection of objects that contains collections that we
don't want to use. <br>
Ex:<br>
 <br>
Model:<br>
 <br>
ClassB<br>
{<br>
  int foo1;<br>
  List childrens1;<br>
  List childrens2;<br>
  List childrens3;<br>
};<br>
 <br>
Code:</div>
<div><br>
Resource.contents contains objects of type ClassB.<br>
 <br>
By fetching instances of classB, we will also fetched some items in the
list(childrens1, childrens2, childrens3) <font face="Courier New"><font
color="#000000">The problem we had.. is we do not know if we want to
use it. SO better not to download them.</font></font></div>
<div><br>
<font color="#000000" face="Courier New">So In our production(we used
our own IStore), we never download any objects from collection. </font><br>
<font color="#000000" face="Courier New">I'm working at the moment to
put in place all feature we used in the current CDO.</font><br>
<font color="#000000" face="Courier New">That one will be part of </font><br>
<a moz-do-not-send="true"
href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477"
target="_blank"><font color="#0068cf">https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477</font></a>.
To begin with,CDORevisionImpl needs to supports list that are 0 even if
<font color="#000000" face="Courier New">referenceChunkSize == 0.</font><br>
 <br>
<font color="#000000" face="Courier New">It is true that we obtain
good performance.</font><br>
<font color="#000000" face="Courier New">Worst case :</font><br>
<font color="#000000" face="Courier New">1500 objects /sec (Real
fetch from disk. Page that contains the objects, wasn't in the cache of
the filesystem.) </font><br>
 <br>
<font color="#000000" face="Courier New">Best case </font><br>
<font color="#000000" face="Courier New">12 000 objects/Sec (Fetch
objects that are already in the case of the filesystem)</font><br>
 <br>
(These statistics always fetch objects from server to client. The cache
client isn't used)<br>
 <br>
<font color="#000000" face="Courier New">We have another optimization
one with SmartReadAhead but for now only work for UI client. (for now) 
This is something we will integrate as well in CDO. But for now we
concentrate on the other things.</font><br>
 <br>
<font color="#000000" face="Courier New">I used an Object database.
Based on my preliminary test without CDO.</font><br>
<font color="#000000" face="Courier New">I compare</font><br>
 <br>
<font color="#000000" face="Courier New">Hibernate vs </font><font
color="#000000" face="Courier New">Objectivity/EMF : </font><br>
<font color="#000000" face="Courier New">Objectivity/EMF is around 3
to 50 times faster than Hibernate.</font><br>
 <br>
<font color="#000000" face="Courier New">The worst.. you will get 30
to 240 objects/sec or</font><br>
<font color="#000000" face="Courier New">the best... you will get 500
to 4000 objects/sec</font><br>
 <br>
<font color="#000000" face="Courier New">Based on your comments...
you are getting the worst (with Derby)!! :-)</font><br>
</div>
</blockquote>
And with the DBStore!!<br>
I'd really like to encourage you to use the HibernateStore. <br>
It is much younger than the DBStore but Hibernate itself should do a
much better job on mapping than the DBStore.<br>
<br>
That said, the DBStore will, for multiple reasons, never cease to exist
in CDO.<br>
<br>
<blockquote cite="mid:g1mkji$h5d$1@build.eclipse.org" type="cite">
<div> <br>
 <br>
Another comments about insertion.<br>
 <br>
We found another problem when we insert data(DOn't know if it is still
true). Resource.Contents is a unique list. Basically each time we
insert one element, it needs to fetch all the collection to see if we
already have this element. Basically.. it is time consuming. In our
case we are not going through this stage to persist our objects... but
the objects are not accessible through that list.<br>
</div>
</blockquote>
I was not aware of this. Sounds as if we should offer an alternative
implementation for Resource.Contents.<br>
Could you please open a Bugzilla to discuss/track this?<br>
<br>
<blockquote cite="mid:g1mkji$h5d$1@build.eclipse.org" type="cite">
<div> </div>
<div> </div>
<div> </div>
<div><font face="Arial" size="2">If speed is an issue for you!! We
(You included :-)) can optimize it. What I like is Eike did a really
good job doing that framwork and optimizations are easy to add.</font></div>
<div><font face="Arial" size="2">Also you can change your back-end
without affecting you client side. (Maybe going to an Object database!!)</font></div>
<div><font face="Arial" size="2">THis was one of the purpose of CDO!!
:-)</font></div>
</blockquote>
Thank you ;-)<br>
Indeed, CDO was intended to focus of the protocol aspects, the
repository and the client side addition to the EMF concepts.<br>
I feel that this will become clearer the more IStore implementations we
get that depend on mature 3rd party code for the mapping part.<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
<blockquote cite="mid:g1mkji$h5d$1@build.eclipse.org" type="cite">
<div> </div>
<div><br>
Simon<br>
<br>
</div>
<blockquote
style="border-left: 2px solid rgb(0, 0, 0); padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div>"Eike Stepper" &lt;<a moz-do-not-send="true"
href="mailto:stepper@sympedia.de">stepper@sympedia.de</a>&gt; a écrit
dans le message de news: <a moz-do-not-send="true"
href="mailto:483E9332.6050800@sympedia.de">483E9332.6050800@sympedia.de</a>...</div>
Hi Cédric,<br>
<br>
That sounds interesting!<br>
Comments inline...<br>
<br>
<br>
Cédric Brun schrieb:
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 Features)

The test is a "quick and dirty" one so please do not take these figures too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
</pre>
</blockquote>
Looks like a sign that the NIO socket channels are efficient ,-)<br>
You used localhost for TCP transport I guess?<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">* First case : building a small model (10000 elements) with the simple MM,
only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
</pre>
</blockquote>
Seems to be consistent with the fact that only for commits there is
remote traffic.<br>
And the backend transaction management is another overhead.<br>
So the impact of the number objects/commit starts with bigger
transactions.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">browsing the just commited elements opening a new transaction and getting a
new Resource instance, I get around 30 000 objets/sec rate just iterating
thanks to Resource.getAllContents().
</pre>
</blockquote>
Hehe, this is a sign that client side caching works well:<br>
All views and transactions of a single session share (and cache) their
object state.<br>
Otherwise I'd expect much smaller values.<br>
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.<br>
But the DBStore (which you used) is not that optimized.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely (I
did not measured it exactly as it was launched during a night, but it seems
I got around 100 objects/sec rate in writting as I was writting every 700
objects.
</pre>
</blockquote>
Sounds not too bad.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">Once the model is built the derby database is 222 MB (which - I heard - is
not so big for derby).
</pre>
</blockquote>
Hmm, I have no extensive experience with Derby.<br>
To be honest, I'm really no database expert (although I can write
simple SQL statements).<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">Retrieving the distant resource and calling eAllContents() on it, I get a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
</pre>
</blockquote>
Currently I'm not sure what exactly eAllContents() does do (iteration
order and so).<br>
There are several CDO features that can have a major impact on load
rates!<br>
<br>
- Collections (xrefs and containment) can be loaded lazily. I don't
mean the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).<br>
<style type="text/css">CODE {
FONT-SIZE: 10pt; MARGIN: 0px; FONT-FAMILY: Courier New, Courier
}
</style><!-- ======================================================== --><!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = --><!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"><code><font color="#7f0055"><b>public interface </b></font><font
color="#000000">CDOSession </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">CDOProtocolSession, IContainer&lt;CDOView&gt; </font><br>
<font color="#000000">{</font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>int </b></font><font color="#000000">getReferenceChunkSize</font><font
color="#000000">()</font><font color="#000000">;</font><br>
<br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setReferenceChunkSize</font><font
color="#000000">(</font><font color="#7f0055"><b>int </b></font><font
color="#000000">referenceChunkSize</font><font color="#000000">)</font><font
color="#000000">;</font></code> </td>
<!-- end source code --></tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = --><br>
<!-- ======================================================== -->-
Loading collection elements (target objects) can be batched (the
current name is even worse)<br>
<style type="text/css">
<!--code { font-family: Courier New, Courier; font-size: 10pt; margin: 0px; }-->
</style><!-- ======================================================== --><!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = --><!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"><code><font color="#7f0055"><b>public interface </b></font><font
color="#000000">CDOView </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">CDOProtocolView, INotifier</font><br>
<font color="#000000">{</font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>int </b></font><font color="#000000">getLoadRevisionCollectionChunkSize</font> <font
color="#000000">()</font><font color="#000000">;</font><br>
<br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setLoadRevisionCollectionChunkSize</font> <font
color="#000000">(</font><font color="#7f0055"><b>int </b></font><font
color="#000000">loadRevisionCollectionChunkSize</font><font
color="#000000">)</font><font color="#000000">;</font></code> </td>
<!-- end source code --></tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = --><!-- ======================================================== --><br>
- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.<br>
<style type="text/css">
<!--code { font-family: Courier New, Courier; font-size: 10pt; margin: 0px; }-->
</style><!-- ======================================================== --><!-- = Java Sourcecode to HTML automatically converted code = --><!-- = Java2Html Converter 5.0 [2006-02-26] by Markus Gebhard markus@jave.de = --><!-- = Further information: http://www.java2html.de = -->
<div class="java" align="left">
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0">
<tbody>
<tr>
<!-- start source code --> <td align="left" nowrap="nowrap"
valign="top"><code><font color="#7f0055"><b>public class </b></font><font
color="#000000">CDOViewImpl </font><font color="#7f0055"><b>extends </b></font><font
color="#000000">org.eclipse.net4j.internal.util.event.Notifier  </font><font
color="#7f0055"><b>implements </b></font><font color="#000000">CDOView, CDOIDProvider,</font>
<font color="#000000">Adapter.Internal</font><br>
<font color="#000000">{</font><br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#000000">CDOFeatureAnalyzer getFeatureAnalyzer</font ><font
color="#000000">()</font><br>
<font color="#ffffff">  </font><font color="#000000">{</font><br>
<font color="#ffffff">    </font><font color="#7f0055"><b>return </b></font><font
color="#000000">featureAnalyzer;</font><br>
<font color="#ffffff">  </font><font color="#000000">}</font><br>
<br>
<font color="#ffffff">  </font><font color="#7f0055"><b>public </b></font><font
color="#7f0055"><b>void </b></font><font color="#000000">setFeatureAnalyzer</font><font
color="#000000">(</font><font color="#000000">CDOFeatureAnalyzer featureAnalyzer</font ><font
color="#000000">)</font><br>
<font color="#ffffff">  </font><font color="#000000">{</font><br>
<font color="#ffffff">    </font><font color="#7f0055"><b>this</b></font><font
color="#000000">.featureAnalyzer = featureAnalyzer ==  </font><font
color="#7f0055"><b>null </b></font><font color="#000000">? CDOFeatureAnalyzer.NOOP : featureAnalyzer; </font><br>
<font color="#ffffff">  </font><font color="#000000">}</font></code>
</td>
<!-- end source code --></tr>
</tbody>
</table>
</div>
<!-- = END of automatically generated HTML code = --><!-- ======================================================== --><br>
- There's a SmartReadAheadThread (if you're curious, please ask Simon).<br>
- Caches can be configured<br>
- ...<br>
<br>
<br>
Known issues of the DBStore:<br>
- When in auditing mode updates are always written as complete inserts
(by design)<br>
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.<br>
- No (few) prepared statements are used (see <a moz-do-not-send="true"
class="moz-txt-link-freetext"
href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487">https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487</a>)<br>
- Maybe others...<br>
<br>
Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.<br>
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore. <br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name="repo1"&gt;
&lt;property name="overrideUUID"
value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name="supportingAudits" value="true"/&gt;
&lt;property name="verifyingRevisions" value="false"/&gt;
&lt;property name="currentLRUCapacity" value="10000"/&gt;
</pre>
</blockquote>
I guess this one could be larger.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap=""> &lt;property name="revisedLRUCapacity" value="100"/&gt;

&lt;store type="db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any user-contributed type&gt; --&gt;
&lt;mappingStrategy type="horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE | ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES --&gt;
&lt;property name="toManyReferences" value="ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES | LIKE_TO_MANY_REFERENCES --&gt;
&lt;property name="toOneReferences" value="LIKE_ATTRIBUTES"/&gt;

&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name="mappingPrecedence" value="MODEL"/&gt;
</pre>
</blockquote>
This one is obsolete.<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap=""> &lt;/mappingStrategy&gt;

&lt;dbAdapter name="derby-embedded"/&gt;
&lt;dataSource class="org.apache.derby.jdbc.EmbeddedDataSource"
databaseName="/tmp/cdodb1"
createDatabase="create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ? </pre>
</blockquote>
As I said that's very difficult to judge.<br>
I believe it's more appropriate to compare the actual values with
values from other measures (other setups, properties, etc. or even
other products) instead of random expectations.<br>
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to
grow slowly ;-)<br>
<br>
<blockquote cite="mid:g1lvjh$jd7$1@build.eclipse.org" type="cite">
<pre wrap="">What are the main reasons fur such figures ?
</pre>
</blockquote>
Hmm, I *suspect* you don't like the figures? I can find no evidence
your assessment ;-)<br>
<br>
Ahh,one more note:<br>
Tracing can also have a significant impact on performance and
end-to-end throughput.<br>
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
</blockquote>
</blockquote>
</body>
</html>

--------------050305010008090907040306--
Re: [CDO] reading/writting throughput performances [message #123816 is a reply to message #123623] Thu, 29 May 2008 17:34 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------010307040705010407070206
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Hi Cedric,

Without your measure I'd say this is unlikely because there are probably
dozens of readString() calls everywhere.
And that would have hit all other users as well.

But maybe it's simply the mass of CDOClassRefImpls that are to be
transfered in your scenario.
Can you please file an enhancement request?
Then I can work on an optimization that transfers single inegers instead
of URI Strings.

Cheers
/Eike



Cédric Brun schrieb:
> Eike,
>
> As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
> relevant, but in the testcase I'm working on (with the complex metamodel,
> big model in database and 50 o/sec throughput) my profiler says that most
> of the time (like 99.9%) is spent in a readString call from
> CDOClassRefImpl :
>
> public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
> IOException
> {
> // TODO Optimize transfer of URIs
> packageURI = in.readString();
> if (packageURI == null)
> {
> packageURI = defaultURI;
> }
>
> classifierID = in.readInt();
> }
>
> The TODO let me think this seems relevant but I'm not sure, what do you
> think of it ?
>
> Cédric
>
>
> Eike Stepper wrote:
>
>
>> Hi Cédric,
>>
>> That sounds interesting!
>> Comments inline...
>>
>>
>> Cédric Brun schrieb:
>>
>>> Hi Eike,
>>>
>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>> measuring read/write throughput when I use CDO (RC2).
>>>
>>> I'm using an embeded-derby database, two different metamodels (complex
>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>> Features)
>>>
>>> The test is a "quick and dirty" one so please do not take these figures
>>> too seriously, I would just like to have your input about the "order of
>>> magnitude" I should expect or settings affecting seriously these
>>> performances. I tried both JVM and TCP acceptor but the performances are
>>> quite similar though JVM is a bit faster.
>>>
>>>
>> Looks like a sign that the NIO socket channels are efficient ,-)
>> You used localhost for TCP transport I guess?
>>
>>
>>> * First case : building a small model (10000 elements) with the simple
>>> MM, only adding instances in an empty database :
>>> commiting change on every add I get a 2 objects per second rate.
>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>
>>>
>> Seems to be consistent with the fact that only for commits there is
>> remote traffic.
>> And the backend transaction management is another overhead.
>> So the impact of the number objects/commit starts with bigger
>> transactions.
>>
>>
>>> browsing the just commited elements opening a new transaction and getting
>>> a new Resource instance, I get around 30 000 objets/sec rate just
>>> iterating thanks to Resource.getAllContents().
>>>
>>>
>> Hehe, this is a sign that client side caching works well:
>> All views and transactions of a single session share (and cache) their
>> object state.
>> Otherwise I'd expect much smaller values.
>> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
>> several thousands objects/sec.
>> But the DBStore (which you used) is not that optimized.
>>
>>
>>> * Second case : I built a big model in the database using the complex
>>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>>> (I did not measured it exactly as it was launched during a night, but it
>>> seems I got around 100 objects/sec rate in writting as I was writting
>>> every 700 objects.
>>>
>>>
>> Sounds not too bad.
>>
>>
>>> Once the model is built the derby database is 222 MB (which - I heard -
>>> is not so big for derby).
>>>
>>>
>> Hmm, I have no extensive experience with Derby.
>> To be honest, I'm really no database expert (although I can write simple
>> SQL statements).
>>
>>
>>> Retrieving the distant resource and calling eAllContents() on it, I get a
>>> 50 Objects/sec rate at best, which mean my eAllContents() call would take
>>> 4 hours !
>>>
>>>
>> Currently I'm not sure what exactly eAllContents() does do (iteration
>> order and so).
>> There are several CDO features that can have a major impact on load rates!
>>
>> - Collections (xrefs and containment) can be loaded lazily. I don't mean
>> the target objects, which are lazy by default anyway, but even the
>> target IDs that are in the collections. We call that "reference
>> chunking" (but search for a better name is ongoing).
>> |*public interface *CDOSession *extends *CDOProtocolSession,
>> |IContainer<CDOView>
>> {
>> *public **int *getReferenceChunkSize();
>>
>> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>>
>>
>> - Loading collection elements (target objects) can be batched (the
>> current name is even worse)
>> |*public interface *CDOView *extends *CDOProtocolView, INotifier
>> {
>> *public **int *getLoadRevisionCollectionChunkSize();
>>
>> *public **void *setLoadRevisionCollectionChunkSize(*int
>> *loadRevisionCollectionChunkSize);|
>>
>>
>>
>> - One of the most sophisticated feature is automatic model usage
>> analyzation. The result are fetch rules that are sent to the server.
>> When later objects are loaded from the server, it can answer with
>> additional objects that are likely to be needed by the client in the
>> near future.
>> |*public class *CDOViewImpl *extends
>> |*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
>> |CDOIDProvider,
>> Adapter.Internal
>> {
>> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
>> {
>> *return *featureAnalyzer;
>> }
>>
>> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
>> {
>> *this*.featureAnalyzer = featureAnalyzer == *null *?
>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>> }|
>>
>>
>> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
>> - Caches can be configured
>> - ...
>>
>>
>> Known issues of the DBStore:
>> - When in auditing mode updates are always written as complete inserts
>> (by design)
>> - When configuring toManyReferences to a value different from
>> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
>> - No (few) prepared statements are used (see
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
>> - Maybe others...
>>
>> Please note that the DBStore was not written by me to compete with
>> Hibernate in terms of performance or mapping capabilities.
>> Now that Martin and I, well in the end mostly Martin, provide a
>> HibernateStore and this HibernateStore gets more and more features I
>> expect that there will be a trend away from the DBStore.
>>
>>
>>> This is probably linked to the way the mapping to db is done, here's the
>>> config I used (came from CDO-server example if I recall correctly).
>>>
>>>
>>> <repository name="repo1">
>>> <property name="overrideUUID"
>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>> <property name="supportingAudits" value="true"/>
>>> <property name="verifyingRevisions" value="false"/>
>>> <property name="currentLRUCapacity" value="10000"/>
>>>
>>>
>> I guess this one could be larger.
>>
>>
>>> <property name="revisedLRUCapacity" value="100"/>
>>>
>>> <store type="db">
>>> <!-- type: horizontal | vertical | <any
>>> user-contributed type> --> <mappingStrategy
>>> type="horizontal">
>>> <!-- ONE_TABLE_PER_REFERENCE |
>>> ONE_TABLE_PER_CLASS |
>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>> <property name="toManyReferences"
>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>
>>> <!-- LIKE_ATTRIBUTES |
>>> LIKE_TO_MANY_REFERENCES --> <property
>>> name="toOneReferences"
>>> value="LIKE_ATTRIBUTES"/>
>>>
>>> <!-- MODEL | STRATEGY -->
>>> <property name="mappingPrecedence"
>>> value="MODEL"/>
>>>
>>>
>> This one is obsolete.
>>
>>
>>> </mappingStrategy>
>>>
>>> <dbAdapter name="derby-embedded"/>
>>> <dataSource
>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>> databaseName="/tmp/cdodb1"
>>> createDatabase="create"/>
>>>
>>> </store>
>>> </repository>
>>>
>>>
>>>
>>>
>>> What do you think about that ? What throughput do you think I should
>>> expect ?
>>>
>> As I said that's very difficult to judge.
>> I believe it's more appropriate to compare the actual values with values
>> from other measures (other setups, properties, etc. or even other
>> products) instead of random expectations.
>> Apologies that I didn't have the time so far to provide some reference
>> measures myself. Maybe this gets better now that the team starts to grow
>> slowly ;-)
>>
>>
>>> What are the main reasons fur such figures ?
>>>
>>>
>> Hmm, I *suspect* you don't like the figures? I can find no evidence your
>> assessment ;-)
>>
>> Ahh,one more note:
>> Tracing can also have a significant impact on performance and end-to-end
>> throughput.
>> Turn it off by all means. And please make sure that it's really turned
>> off, not only invisible (i.e. console is not a target).
>>
>> Cheers
>> /Eike
>>
>
>

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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<head>
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Hi Cedric,<br>
<br>
Without your measure I'd say this is unlikely because there are
probably dozens of readString() calls everywhere.<br>
And that would have hit all other users as well.<br>
<br>
But maybe it's simply the mass of CDOClassRefImpls  that are to be
transfered in your scenario.<br>
Can you please file an enhancement request? <br>
Then I can work on an optimization that transfers single inegers
instead of URI Strings.<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
<br>
Cédric Brun schrieb:
<blockquote cite="mid:g1mbhe$2cl$1@build.eclipse.org" type="cite">
<pre wrap="">Eike,

As I don't know (yet ;) ) all the internals of CDO I'm not sure this is
relevant, but in the testcase I'm working on (with the complex metamodel,
big model in database and 50 o/sec throughput) my profiler says that most
of the time (like 99.9%) is spent in a readString call from
CDOClassRefImpl :

public CDOClassRefImpl(ExtendedDataInput in, String defaultURI) throws
IOException
{
// TODO Optimize transfer of URIs
packageURI = in.readString();
if (packageURI == null)
{
packageURI = defaultURI;
}

classifierID = in.readInt();
}

The TODO let me think this seems relevant but I'm not sure, what do you
think of it ?

Cédric


Eike Stepper wrote:

</pre>
<blockquote type="cite">
<pre wrap="">Hi Cédric,

That sounds interesting!
Comments inline...


Cédric Brun schrieb:
</pre>
<blockquote type="cite">
<pre wrap="">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex
one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
Features)

The test is a "quick and dirty" one so please do not take these figures
too seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.

</pre>
</blockquote>
<pre wrap="">Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?

</pre>
<blockquote type="cite">
<pre wrap="">* First case : building a small model (10000 elements) with the simple
MM, only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.

</pre>
</blockquote>
<pre wrap="">Seems to be consistent with the fact that only for commits there is
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger
transactions.

</pre>
<blockquote type="cite">
<pre wrap="">browsing the just commited elements opening a new transaction and getting
a new Resource instance, I get around 30 000 objets/sec rate just
iterating thanks to Resource.getAllContents().

</pre>
</blockquote>
<pre wrap="">Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) their
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.
But the DBStore (which you used) is not that optimized.

</pre>
<blockquote type="cite">
<pre wrap="">* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely
(I did not measured it exactly as it was launched during a night, but it
seems I got around 100 objects/sec rate in writting as I was writting
every 700 objects.

</pre>
</blockquote>
<pre wrap="">Sounds not too bad.

</pre>
<blockquote type="cite">
<pre wrap="">Once the model is built the derby database is 222 MB (which - I heard -
is not so big for derby).

</pre>
</blockquote>
<pre wrap="">Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write simple
SQL statements).

</pre>
<blockquote type="cite">
<pre wrap="">Retrieving the distant resource and calling eAllContents() on it, I get a
50 Objects/sec rate at best, which mean my eAllContents() call would take
4 hours !

</pre>
</blockquote>
<pre wrap="">Currently I'm not sure what exactly eAllContents() does do (iteration
order and so).
There are several CDO features that can have a major impact on load rates!

- Collections (xrefs and containment) can be loaded lazily. I don't mean
the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).
|*public interface *CDOSession *extends *CDOProtocolSession,
|IContainer&lt;CDOView&gt;
{
*public **int *getReferenceChunkSize();

*public **void *setReferenceChunkSize(*int *referenceChunkSize);|


- Loading collection elements (target objects) can be batched (the
current name is even worse)
|*public interface *CDOView *extends *CDOProtocolView, INotifier
{
*public **int *getLoadRevisionCollectionChunkSize();

*public **void *setLoadRevisionCollectionChunkSize(*int
*loadRevisionCollectionChunkSize);|



- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.
|*public class *CDOViewImpl *extends
|*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
|CDOIDProvider,
Adapter.Internal
{
*public *CDOFeatureAnalyzer getFeatureAnalyzer()
{
*return *featureAnalyzer;
}

*public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
{
*this*.featureAnalyzer = featureAnalyzer == *null *?
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
}|


- There's a SmartReadAheadThread (if you're curious, please ask Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts
(by design)
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see
<a class="moz-txt-link-freetext" href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487">https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487</a>)
- Maybe others...

Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore.

</pre>
<blockquote type="cite">
<pre wrap="">This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name="repo1"&gt;
&lt;property name="overrideUUID"
value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name="supportingAudits" value="true"/&gt;
&lt;property name="verifyingRevisions" value="false"/&gt;
&lt;property name="currentLRUCapacity" value="10000"/&gt;

</pre>
</blockquote>
<pre wrap="">I guess this one could be larger.

</pre>
<blockquote type="cite">
<pre wrap=""> &lt;property name="revisedLRUCapacity" value="100"/&gt;

&lt;store type="db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any
user-contributed type&gt; --&gt; &lt;mappingStrategy
type="horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE |
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES --&gt;
&lt;property name="toManyReferences"
value="ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES |
LIKE_TO_MANY_REFERENCES --&gt; &lt;property
name="toOneReferences"
value="LIKE_ATTRIBUTES"/&gt;

&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name="mappingPrecedence"
value="MODEL"/&gt;

</pre>
</blockquote>
<pre wrap="">This one is obsolete.

</pre>
<blockquote type="cite">
<pre wrap=""> &lt;/mappingStrategy&gt;

&lt;dbAdapter name="derby-embedded"/&gt;
&lt;dataSource
class="org.apache.derby.jdbc.EmbeddedDataSource"
databaseName="/tmp/cdodb1"
createDatabase="create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ?
</pre>
</blockquote>
<pre wrap="">As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with values
from other measures (other setups, properties, etc. or even other
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to grow
slowly ;-)

</pre>
<blockquote type="cite">
<pre wrap="">What are the main reasons fur such figures ?

</pre>
</blockquote>
<pre wrap="">Hmm, I *suspect* you don't like the figures? I can find no evidence your
assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and end-to-end
throughput.
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).

Cheers
/Eike
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
</body>
</html>

--------------010307040705010407070206--
Re: [CDO] reading/writting throughput performances [message #123831 is a reply to message #123610] Thu, 29 May 2008 17:42 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
--------------030500070800010205060903
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Cédric Brun schrieb:
> Eike,
>
> thanks for your detailled answer, I'll digg further and try to profile the
> Net4J/CDO stack so that I understand the "50 objects/sec rate" when
> retrieving data (which I think is surprisingly low).
>
Looking forward to new insights!

> Concerning the logging, what can I change to be *sure* that no logging will
> occurs ?
>
In Net4j/CDO there's a basic difference between logging and tracing.
Logging is for important production information (I always advise against
using the DEBUG loglevel!) and can't be switched off.

Tracing can be configured in several dimensions, per bundle, per tracer
hierachy, per trace context (usually == classname).
If you launch an OSGi Framework or Eclipse Application you can control
tracing via the Tracing page of the launch config.
In stand-alone mode call OMPlatform.INSTANCE.setDebugging(false).

Simply removing all ITraceHandlers is not enough.
If you set a breakpoint in
org.eclipse.net4j.internal.util.bundle.AbstractPlatform.trac e(OMTraceHandlerEvent)
you can be absolutely sure.

Cheers
/Eike


> Cheers,
>
> Cédric
>
>
>
> Eike Stepper wrote:
>
>
>> Hi Cédric,
>>
>> That sounds interesting!
>> Comments inline...
>>
>>
>> Cédric Brun schrieb:
>>
>>> Hi Eike,
>>>
>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>> measuring read/write throughput when I use CDO (RC2).
>>>
>>> I'm using an embeded-derby database, two different metamodels (complex
>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>> Features)
>>>
>>> The test is a "quick and dirty" one so please do not take these figures
>>> too seriously, I would just like to have your input about the "order of
>>> magnitude" I should expect or settings affecting seriously these
>>> performances. I tried both JVM and TCP acceptor but the performances are
>>> quite similar though JVM is a bit faster.
>>>
>>>
>> Looks like a sign that the NIO socket channels are efficient ,-)
>> You used localhost for TCP transport I guess?
>>
>>
>>> * First case : building a small model (10000 elements) with the simple
>>> MM, only adding instances in an empty database :
>>> commiting change on every add I get a 2 objects per second rate.
>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>
>>>
>> Seems to be consistent with the fact that only for commits there is
>> remote traffic.
>> And the backend transaction management is another overhead.
>> So the impact of the number objects/commit starts with bigger
>> transactions.
>>
>>
>>> browsing the just commited elements opening a new transaction and getting
>>> a new Resource instance, I get around 30 000 objets/sec rate just
>>> iterating thanks to Resource.getAllContents().
>>>
>>>
>> Hehe, this is a sign that client side caching works well:
>> All views and transactions of a single session share (and cache) their
>> object state.
>> Otherwise I'd expect much smaller values.
>> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
>> several thousands objects/sec.
>> But the DBStore (which you used) is not that optimized.
>>
>>
>>> * Second case : I built a big model in the database using the complex
>>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>>> (I did not measured it exactly as it was launched during a night, but it
>>> seems I got around 100 objects/sec rate in writting as I was writting
>>> every 700 objects.
>>>
>>>
>> Sounds not too bad.
>>
>>
>>> Once the model is built the derby database is 222 MB (which - I heard -
>>> is not so big for derby).
>>>
>>>
>> Hmm, I have no extensive experience with Derby.
>> To be honest, I'm really no database expert (although I can write simple
>> SQL statements).
>>
>>
>>> Retrieving the distant resource and calling eAllContents() on it, I get a
>>> 50 Objects/sec rate at best, which mean my eAllContents() call would take
>>> 4 hours !
>>>
>>>
>> Currently I'm not sure what exactly eAllContents() does do (iteration
>> order and so).
>> There are several CDO features that can have a major impact on load rates!
>>
>> - Collections (xrefs and containment) can be loaded lazily. I don't mean
>> the target objects, which are lazy by default anyway, but even the
>> target IDs that are in the collections. We call that "reference
>> chunking" (but search for a better name is ongoing).
>> |*public interface *CDOSession *extends *CDOProtocolSession,
>> |IContainer<CDOView>
>> {
>> *public **int *getReferenceChunkSize();
>>
>> *public **void *setReferenceChunkSize(*int *referenceChunkSize);|
>>
>>
>> - Loading collection elements (target objects) can be batched (the
>> current name is even worse)
>> |*public interface *CDOView *extends *CDOProtocolView, INotifier
>> {
>> *public **int *getLoadRevisionCollectionChunkSize();
>>
>> *public **void *setLoadRevisionCollectionChunkSize(*int
>> *loadRevisionCollectionChunkSize);|
>>
>>
>>
>> - One of the most sophisticated feature is automatic model usage
>> analyzation. The result are fetch rules that are sent to the server.
>> When later objects are loaded from the server, it can answer with
>> additional objects that are likely to be needed by the client in the
>> near future.
>> |*public class *CDOViewImpl *extends
>> |*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
>> |CDOIDProvider,
>> Adapter.Internal
>> {
>> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
>> {
>> *return *featureAnalyzer;
>> }
>>
>> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
>> {
>> *this*.featureAnalyzer = featureAnalyzer == *null *?
>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>> }|
>>
>>
>> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
>> - Caches can be configured
>> - ...
>>
>>
>> Known issues of the DBStore:
>> - When in auditing mode updates are always written as complete inserts
>> (by design)
>> - When configuring toManyReferences to a value different from
>> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
>> - No (few) prepared statements are used (see
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
>> - Maybe others...
>>
>> Please note that the DBStore was not written by me to compete with
>> Hibernate in terms of performance or mapping capabilities.
>> Now that Martin and I, well in the end mostly Martin, provide a
>> HibernateStore and this HibernateStore gets more and more features I
>> expect that there will be a trend away from the DBStore.
>>
>>
>>> This is probably linked to the way the mapping to db is done, here's the
>>> config I used (came from CDO-server example if I recall correctly).
>>>
>>>
>>> <repository name="repo1">
>>> <property name="overrideUUID"
>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>> <property name="supportingAudits" value="true"/>
>>> <property name="verifyingRevisions" value="false"/>
>>> <property name="currentLRUCapacity" value="10000"/>
>>>
>>>
>> I guess this one could be larger.
>>
>>
>>> <property name="revisedLRUCapacity" value="100"/>
>>>
>>> <store type="db">
>>> <!-- type: horizontal | vertical | <any
>>> user-contributed type> --> <mappingStrategy
>>> type="horizontal">
>>> <!-- ONE_TABLE_PER_REFERENCE |
>>> ONE_TABLE_PER_CLASS |
>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>> <property name="toManyReferences"
>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>
>>> <!-- LIKE_ATTRIBUTES |
>>> LIKE_TO_MANY_REFERENCES --> <property
>>> name="toOneReferences"
>>> value="LIKE_ATTRIBUTES"/>
>>>
>>> <!-- MODEL | STRATEGY -->
>>> <property name="mappingPrecedence"
>>> value="MODEL"/>
>>>
>>>
>> This one is obsolete.
>>
>>
>>> </mappingStrategy>
>>>
>>> <dbAdapter name="derby-embedded"/>
>>> <dataSource
>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>> databaseName="/tmp/cdodb1"
>>> createDatabase="create"/>
>>>
>>> </store>
>>> </repository>
>>>
>>>
>>>
>>>
>>> What do you think about that ? What throughput do you think I should
>>> expect ?
>>>
>> As I said that's very difficult to judge.
>> I believe it's more appropriate to compare the actual values with values
>> from other measures (other setups, properties, etc. or even other
>> products) instead of random expectations.
>> Apologies that I didn't have the time so far to provide some reference
>> measures myself. Maybe this gets better now that the team starts to grow
>> slowly ;-)
>>
>>
>>> What are the main reasons fur such figures ?
>>>
>>>
>> Hmm, I *suspect* you don't like the figures? I can find no evidence your
>> assessment ;-)
>>
>> Ahh,one more note:
>> Tracing can also have a significant impact on performance and end-to-end
>> throughput.
>> Turn it off by all means. And please make sure that it's really turned
>> off, not only invisible (i.e. console is not a target).
>>
>> Cheers
>> /Eike
>>
>
>

--------------030500070800010205060903
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Cédric Brun schrieb:
<blockquote cite="mid:g1m91c$i2q$1@build.eclipse.org" type="cite">
<pre wrap="">Eike,

thanks for your detailled answer, I'll digg further and try to profile the
Net4J/CDO stack so that I understand the "50 objects/sec rate" when
retrieving data (which I think is surprisingly low).
</pre>
</blockquote>
Looking forward to new insights!<br>
<br>
<blockquote cite="mid:g1m91c$i2q$1@build.eclipse.org" type="cite">
<pre wrap="">
Concerning the logging, what can I change to be *sure* that no logging will
occurs ?
</pre>
</blockquote>
In Net4j/CDO there's a basic difference between logging and tracing.<br>
Logging is for important production information (I always advise
against using the DEBUG loglevel!) and can't be switched off.<br>
<br>
Tracing can be configured in several dimensions, per bundle, per tracer
hierachy, per trace context (usually == classname).<br>
If you launch an OSGi Framework or Eclipse Application you can control
tracing via the Tracing page of the launch config.<br>
In stand-alone mode call OMPlatform.INSTANCE.setDebugging(false).<br>
<br>
Simply removing all ITraceHandlers is not enough.<br>
If you set a breakpoint in
org.eclipse.net4j.internal.util.bundle.AbstractPlatform.trac e(OMTraceHandlerEvent)
you can be absolutely sure.<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
<blockquote cite="mid:g1m91c$i2q$1@build.eclipse.org" type="cite">
<pre wrap="">
Cheers,

Cédric



Eike Stepper wrote:

</pre>
<blockquote type="cite">
<pre wrap="">Hi Cédric,

That sounds interesting!
Comments inline...


Cédric Brun schrieb:
</pre>
<blockquote type="cite">
<pre wrap="">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex
one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
Features)

The test is a "quick and dirty" one so please do not take these figures
too seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.

</pre>
</blockquote>
<pre wrap="">Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?

</pre>
<blockquote type="cite">
<pre wrap="">* First case : building a small model (10000 elements) with the simple
MM, only adding instances in an empty database :
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.

</pre>
</blockquote>
<pre wrap="">Seems to be consistent with the fact that only for commits there is
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger
transactions.

</pre>
<blockquote type="cite">
<pre wrap="">browsing the just commited elements opening a new transaction and getting
a new Resource instance, I get around 30 000 objets/sec rate just
iterating thanks to Resource.getAllContents().

</pre>
</blockquote>
<pre wrap="">Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) their
object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached rates of
several thousands objects/sec.
But the DBStore (which you used) is not that optimized.

</pre>
<blockquote type="cite">
<pre wrap="">* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely
(I did not measured it exactly as it was launched during a night, but it
seems I got around 100 objects/sec rate in writting as I was writting
every 700 objects.

</pre>
</blockquote>
<pre wrap="">Sounds not too bad.

</pre>
<blockquote type="cite">
<pre wrap="">Once the model is built the derby database is 222 MB (which - I heard -
is not so big for derby).

</pre>
</blockquote>
<pre wrap="">Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write simple
SQL statements).

</pre>
<blockquote type="cite">
<pre wrap="">Retrieving the distant resource and calling eAllContents() on it, I get a
50 Objects/sec rate at best, which mean my eAllContents() call would take
4 hours !

</pre>
</blockquote>
<pre wrap="">Currently I'm not sure what exactly eAllContents() does do (iteration
order and so).
There are several CDO features that can have a major impact on load rates!

- Collections (xrefs and containment) can be loaded lazily. I don't mean
the target objects, which are lazy by default anyway, but even the
target IDs that are in the collections. We call that "reference
chunking" (but search for a better name is ongoing).
|*public interface *CDOSession *extends *CDOProtocolSession,
|IContainer&lt;CDOView&gt;
{
*public **int *getReferenceChunkSize();

*public **void *setReferenceChunkSize(*int *referenceChunkSize);|


- Loading collection elements (target objects) can be batched (the
current name is even worse)
|*public interface *CDOView *extends *CDOProtocolView, INotifier
{
*public **int *getLoadRevisionCollectionChunkSize();

*public **void *setLoadRevisionCollectionChunkSize(*int
*loadRevisionCollectionChunkSize);|



- One of the most sophisticated feature is automatic model usage
analyzation. The result are fetch rules that are sent to the server.
When later objects are loaded from the server, it can answer with
additional objects that are likely to be needed by the client in the
near future.
|*public class *CDOViewImpl *extends
|*org.eclipse.net4j.internal.util.event.Notifier *implements *CDOView,
|CDOIDProvider,
Adapter.Internal
{
*public *CDOFeatureAnalyzer getFeatureAnalyzer()
{
*return *featureAnalyzer;
}

*public **void *setFeatureAnalyzer(CDOFeatureAnalyzer featureAnalyzer)
{
*this*.featureAnalyzer = featureAnalyzer == *null *?
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
}|


- There's a SmartReadAheadThread (if you're curious, please ask Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete inserts
(by design)
- When configuring toManyReferences to a value different from
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see
<a class="moz-txt-link-freetext" href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487">https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487</a>)
- Maybe others...

Please note that the DBStore was not written by me to compete with
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a
HibernateStore and this HibernateStore gets more and more features I
expect that there will be a trend away from the DBStore.

</pre>
<blockquote type="cite">
<pre wrap="">This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name="repo1"&gt;
&lt;property name="overrideUUID"
value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name="supportingAudits" value="true"/&gt;
&lt;property name="verifyingRevisions" value="false"/&gt;
&lt;property name="currentLRUCapacity" value="10000"/&gt;

</pre>
</blockquote>
<pre wrap="">I guess this one could be larger.

</pre>
<blockquote type="cite">
<pre wrap=""> &lt;property name="revisedLRUCapacity" value="100"/&gt;

&lt;store type="db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any
user-contributed type&gt; --&gt; &lt;mappingStrategy
type="horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE |
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES --&gt;
&lt;property name="toManyReferences"
value="ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES |
LIKE_TO_MANY_REFERENCES --&gt; &lt;property
name="toOneReferences"
value="LIKE_ATTRIBUTES"/&gt;

&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name="mappingPrecedence"
value="MODEL"/&gt;

</pre>
</blockquote>
<pre wrap="">This one is obsolete.

</pre>
<blockquote type="cite">
<pre wrap=""> &lt;/mappingStrategy&gt;

&lt;dbAdapter name="derby-embedded"/&gt;
&lt;dataSource
class="org.apache.derby.jdbc.EmbeddedDataSource"
databaseName="/tmp/cdodb1"
createDatabase="create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ?
</pre>
</blockquote>
<pre wrap="">As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with values
from other measures (other setups, properties, etc. or even other
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some reference
measures myself. Maybe this gets better now that the team starts to grow
slowly ;-)

</pre>
<blockquote type="cite">
<pre wrap="">What are the main reasons fur such figures ?

</pre>
</blockquote>
<pre wrap="">Hmm, I *suspect* you don't like the figures? I can find no evidence your
assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and end-to-end
throughput.
Turn it off by all means. And please make sure that it's really turned
off, not only invisible (i.e. console is not a target).

Cheers
/Eike
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
</body>
</html>

--------------030500070800010205060903--
Re: [CDO] reading/writting throughput performances [message #123859 is a reply to message #123770] Thu, 29 May 2008 19:00 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

Eike Stepper schrieb:
> Mark,
>
> Thank you to encourage me ;-)
> RC3 will have the change.
Please cc yourself if you want:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=234702

>
> Cheers
> /Eike
>
>
>
> Mark Geib schrieb:
>> I would vote to make the change. You will be sorry if you miss this
>> opportunity. The users can handle the change I think.
>>
>> Just my thoughts,
>> Mark.
>>
>>
>>
>> Eike Stepper wrote:
>>> Simon McDuff schrieb:
>>>> Good point Eike,
>>>>
>>>> Cedric,
>>>>
>>>> How do you create your CDOSessionIMpl ?
>>>> Are you using your own mechanism ?
>>>>
>>>> Because it could still occured in the case we doesn`t go through
>>>> CDOSessionConfigurationImpl and create directly the CDOSession
>>> You could be right, too. Basically I hate myself because once I
>>> advocated for default legacy support!!! You remember these
>>> discussions? Since several months now I'd really like to change that
>>> (and the checkbox in the OpenSessionDialog is early evidence). I
>>> didn't dare to do it because formerly disableLegacyObjects was a
>>> ctor arg and a semantic change would have broken all clients without
>>> compiler warning. Now that there are no ctor args anymore IO really
>>> consider making this change a late one for Ganymede. Otherwise we'd
>>> have to carry this odd issue for another year and maybe maintain two
>>> different versions of the semantic. What do you think?
>>>
>>>>
>>>> Ex:
>>>>
>>>> CDOSession session = CDOSessionImpl();
>>>>
>>>> By default disablyLegacySystem is false.
>>>>
>>>> In this case Eike, Do we have something else to avoid that ? Maybe
>>>> I`m not aware of other mechanism.
>>> I can add the same check to doBeforeActivate(), too.
>>>
>>> Cheers
>>> /Eike
>>>
>>>>
>>>> Simon
>>>>
>>>> "Eike Stepper" <stepper@sympedia.de <mailto:stepper@sympedia.de>> a
>>>> écrit dans le message de news: 483ED9A4.7010302@sympedia.de
>>>> <mailto:483ED9A4.7010302@sympedia.de>...
>>>>
>>>>
>>>>
>>>> Simon McDuff schrieb:
>>>>> Did you disable the following :
>>>>> CDOSessionConfigurationImpl.setLegacySupportEnabled(true);
>>>>>
>>>>> before opening your session ?
>>>>>
>>>>> This could cause what you are observing ?
>>>>>
>>>>> If your classes are generating with CDOObjectImpl as the super
>>>>> class, you can disableLegacySupport by putting it at true.
>>>>>
>>>> Good point in general!
>>>>
>>>> But I added some logic some time ago that ensures that *session
>>>> legacy support* can only be enabled if the *legacy system* is
>>>> available in general:
>>>>
>>>> | *public **void *setDisableLegacyObjects(*boolean
>>>> *disableLegacyObjects)
>>>> {
>>>> checkInactive();
>>>> *if *(!disableLegacyObjects &&
>>>> !FSMUtil.isLegacySystemAvailable())
>>>> {
>>>> *throw new *LegacySystemNotAvailableException();
>>>> }
>>>>
>>>> *this*.disableLegacyObjects = disableLegacyObjects;
>>>> }|
>>>>
>>>>
>>>> Notice that the whole legacy system is currently (since the work
>>>> on the HibernateStore) broken.
>>>> The needed CDOWeaver is currently not part of the distro anymore
>>>> (also due to issues with the build system).
>>>>
>>>> This altogether seems to exclude the legacy system as root cause
>>>> for performance degradation.
>>>>
>>>> Cheers
>>>> /Eike
>>>>
>>>>
>>>>
>>>>> Simon
>>>>>
>>>>>
>>>>> "Cédric Brun" <cedric.brun@obeo.fr> a écrit dans le message de
>>>>> news: g1mbhe$2cl$1@build.eclipse..org...
>>>>>
>>>>>> Eike,
>>>>>>
>>>>>> As I don't know (yet ;) ) all the internals of CDO I'm not
>>>>>> sure this is
>>>>>> relevant, but in the testcase I'm working on (with the
>>>>>> complex metamodel,
>>>>>> big model in database and 50 o/sec throughput) my profiler
>>>>>> says that most
>>>>>> of the time (like 99.9%) is spent in a readString call from
>>>>>> CDOClassRefImpl :
>>>>>>
>>>>>> public CDOClassRefImpl(ExtendedDataInput in, String
>>>>>> defaultURI) throws
>>>>>> IOException
>>>>>> {
>>>>>> // TODO Optimize transfer of URIs
>>>>>> packageURI = in.readString();
>>>>>> if (packageURI == null)
>>>>>> {
>>>>>> packageURI = defaultURI;
>>>>>> }
>>>>>>
>>>>>> classifierID = in.readInt();
>>>>>> }
>>>>>>
>>>>>> The TODO let me think this seems relevant but I'm not sure,
>>>>>> what do you
>>>>>> think of it ?
>>>>>>
>>>>>> Cédric
>>>>>>
>>>>>>
>>>>>> Eike Stepper wrote:
>>>>>>
>>>>>>
>>>>>>> Hi Cédric,
>>>>>>>
>>>>>>> That sounds interesting!
>>>>>>> Comments inline...
>>>>>>>
>>>>>>>
>>>>>>> Cédric Brun schrieb:
>>>>>>>
>>>>>>>> Hi Eike,
>>>>>>>>
>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>> unit-tests
>>>>>>>> measuring read/write throughput when I use CDO (RC2).
>>>>>>>>
>>>>>>>> I'm using an embeded-derby database, two different
>>>>>>>> metamodels (complex
>>>>>>>> one - 250 EClassifiers/300 features and a simple one - 1
>>>>>>>> Classifier/3
>>>>>>>> Features)
>>>>>>>>
>>>>>>>> The test is a "quick and dirty" one so please do not take
>>>>>>>> these figures
>>>>>>>> too seriously, I would just like to have your input about
>>>>>>>> the "order of
>>>>>>>> magnitude" I should expect or settings affecting seriously
>>>>>>>> these
>>>>>>>> performances. I tried both JVM and TCP acceptor but the
>>>>>>>> performances are
>>>>>>>> quite similar though JVM is a bit faster.
>>>>>>>>
>>>>>>>>
>>>>>>> Looks like a sign that the NIO socket channels are efficient
>>>>>>> ,-)
>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>
>>>>>>>
>>>>>>>> * First case : building a small model (10000 elements) with
>>>>>>>> the simple
>>>>>>>> MM, only adding instances in an empty database :
>>>>>>>> commiting change on every add I get a 2 objects per second
>>>>>>>> rate.
>>>>>>>> commiting changes every 10 adds - I get a 30 objects per
>>>>>>>> second rate.
>>>>>>>>
>>>>>>>>
>>>>>>> Seems to be consistent with the fact that only for commits
>>>>>>> there is
>>>>>>> remote traffic.
>>>>>>> And the backend transaction management is another overhead.
>>>>>>> So the impact of the number objects/commit starts with bigger
>>>>>>> transactions.
>>>>>>>
>>>>>>>
>>>>>>>> browsing the just commited elements opening a new
>>>>>>>> transaction and getting
>>>>>>>> a new Resource instance, I get around 30 000 objets/sec
>>>>>>>> rate just
>>>>>>>> iterating thanks to Resource.getAllContents().
>>>>>>>>
>>>>>>>>
>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>> All views and transactions of a single session share (and
>>>>>>> cache) their
>>>>>>> object state.
>>>>>>> Otherwise I'd expect much smaller values.
>>>>>>> With his ObjectivityStore implementation Simon (cc'ed)
>>>>>>> reached rates of
>>>>>>> several thousands objects/sec.
>>>>>>> But the DBStore (which you used) is not that optimized.
>>>>>>>
>>>>>>>
>>>>>>>> * Second case : I built a big model in the database using
>>>>>>>> the complex
>>>>>>>> metamodel. It contains 700 000 elements. The creation went
>>>>>>>> pretty nicely
>>>>>>>> (I did not measured it exactly as it was launched during a
>>>>>>>> night, but it
>>>>>>>> seems I got around 100 objects/sec rate in writting as I
>>>>>>>> was writting
>>>>>>>> every 700 objects.
>>>>>>>>
>>>>>>>>
>>>>>>> Sounds not too bad.
>>>>>>>
>>>>>>>
>>>>>>>> Once the model is built the derby database is 222 MB (which
>>>>>>>> - I heard -
>>>>>>>> is not so big for derby).
>>>>>>>>
>>>>>>>>
>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>> To be honest, I'm really no database expert (although I can
>>>>>>> write simple
>>>>>>> SQL statements).
>>>>>>>
>>>>>>>
>>>>>>>> Retrieving the distant resource and calling eAllContents()
>>>>>>>> on it, I get a
>>>>>>>> 50 Objects/sec rate at best, which mean my eAllContents()
>>>>>>>> call would take
>>>>>>>> 4 hours !
>>>>>>>>
>>>>>>>>
>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>> (iteration
>>>>>>> order and so).
>>>>>>> There are several CDO features that can have a major impact
>>>>>>> on load rates!
>>>>>>>
>>>>>>> - Collections (xrefs and containment) can be loaded lazily.
>>>>>>> I don't mean
>>>>>>> the target objects, which are lazy by default anyway, but
>>>>>>> even the
>>>>>>> target IDs that are in the collections. We call that "reference
>>>>>>> chunking" (but search for a better name is ongoing).
>>>>>>> |*public interface *CDOSession *extends *CDOProtocolSession,
>>>>>>> |IContainer<CDOView>
>>>>>>> {
>>>>>>> *public **int *getReferenceChunkSize();
>>>>>>>
>>>>>>> *public **void *setReferenceChunkSize(*int
>>>>>>> *referenceChunkSize);|
>>>>>>>
>>>>>>>
>>>>>>> - Loading collection elements (target objects) can be
>>>>>>> batched (the
>>>>>>> current name is even worse)
>>>>>>> |*public interface *CDOView *extends *CDOProtocolView,
>>>>>>> INotifier
>>>>>>> {
>>>>>>> *public **int *getLoadRevisionCollectionChunkSize();
>>>>>>>
>>>>>>> *public **void *setLoadRevisionCollectionChunkSize(*int
>>>>>>> *loadRevisionCollectionChunkSize);|
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> - One of the most sophisticated feature is automatic model
>>>>>>> usage
>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>> server.
>>>>>>> When later objects are loaded from the server, it can answer
>>>>>>> with
>>>>>>> additional objects that are likely to be needed by the
>>>>>>> client in the
>>>>>>> near future.
>>>>>>> |*public class *CDOViewImpl *extends
>>>>>>> |*org.eclipse.net4j.internal.util.event.Notifier *implements
>>>>>>> *CDOView,
>>>>>>> |CDOIDProvider,
>>>>>>> Adapter.Internal
>>>>>>> {
>>>>>>> *public *CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>> {
>>>>>>> *return *featureAnalyzer;
>>>>>>> }
>>>>>>>
>>>>>>> *public **void *setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>> featureAnalyzer)
>>>>>>> {
>>>>>>> *this*.featureAnalyzer = featureAnalyzer == *null *?
>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>> }|
>>>>>>>
>>>>>>>
>>>>>>> - There's a SmartReadAheadThread (if you're curious, please
>>>>>>> ask Simon).
>>>>>>> - Caches can be configured
>>>>>>> - ...
>>>>>>>
>>>>>>>
>>>>>>> Known issues of the DBStore:
>>>>>>> - When in auditing mode updates are always written as
>>>>>>> complete inserts
>>>>>>> (by design)
>>>>>>> - When configuring toManyReferences to a value different from
>>>>>>> LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
>>>>>>> - No (few) prepared statements are used (see
>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487)
>>>>>>> - Maybe others...
>>>>>>>
>>>>>>> Please note that the DBStore was not written by me to
>>>>>>> compete with
>>>>>>> Hibernate in terms of performance or mapping capabilities.
>>>>>>> Now that Martin and I, well in the end mostly Martin, provide a
>>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>>> features I
>>>>>>> expect that there will be a trend away from the DBStore.
>>>>>>>
>>>>>>>
>>>>>>>> This is probably linked to the way the mapping to db is
>>>>>>>> done, here's the
>>>>>>>> config I used (came from CDO-server example if I recall
>>>>>>>> correctly).
>>>>>>>>
>>>>>>>>
>>>>>>>> <repository name="repo1">
>>>>>>>> <property name="overrideUUID"
>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>> <property name="supportingAudits"
>>>>>>>> value="true"/>
>>>>>>>> <property name="verifyingRevisions"
>>>>>>>> value="false"/>
>>>>>>>> <property name="currentLRUCapacity"
>>>>>>>> value="10000"/>
>>>>>>>>
>>>>>>>>
>>>>>>> I guess this one could be larger.
>>>>>>>
>>>>>>>
>>>>>>>> <property name="revisedLRUCapacity"
>>>>>>>> value="100"/>
>>>>>>>>
>>>>>>>> <store type="db">
>>>>>>>> <!-- type: horizontal | vertical |
>>>>>>>> <any
>>>>>>>> user-contributed type> -->
>>>>>>>> <mappingStrategy
>>>>>>>> type="horizontal">
>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>>> LIKE_ATTRIBUTES -->
>>>>>>>> <property
>>>>>>>> name="toManyReferences"
>>>>>>>>
>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>
>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>> <property
>>>>>>>> name="toOneReferences"
>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>
>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>> <property
>>>>>>>> name="mappingPrecedence"
>>>>>>>> value="MODEL"/>
>>>>>>>>
>>>>>>>>
>>>>>>> This one is obsolete.
>>>>>>>
>>>>>>>
>>>>>>>> </mappingStrategy>
>>>>>>>>
>>>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>>>> <dataSource
>>>>>>>>
>>>>>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>>> createDatabase="create"/>
>>>>>>>>
>>>>>>>> </store>
>>>>>>>> </repository>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> What do you think about that ? What throughput do you think
>>>>>>>> I should
>>>>>>>> expect ?
>>>>>>>>
>>>>>>> As I said that's very difficult to judge.
>>>>>>> I believe it's more appropriate to compare the actual values
>>>>>>> with values
>>>>>>> from other measures (other setups, properties, etc. or even
>>>>>>> other
>>>>>>> products) instead of random expectations.
>>>>>>> Apologies that I didn't have the time so far to provide some
>>>>>>> reference
>>>>>>> measures myself. Maybe this gets better now that the team
>>>>>>> starts to grow
>>>>>>> slowly ;-)
>>>>>>>
>>>>>>>
>>>>>>>> What are the main reasons fur such figures ?
>>>>>>>>
>>>>>>>>
>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>> evidence your
>>>>>>> assessment ;-)
>>>>>>>
>>>>>>> Ahh,one more note:
>>>>>>> Tracing can also have a significant impact on performance
>>>>>>> and end-to-end
>>>>>>> throughput.
>>>>>>> Turn it off by all means. And please make sure that it's
>>>>>>> really turned
>>>>>>> off, not only invisible (i.e. console is not a target).
>>>>>>>
>>>>>>> Cheers
>>>>>>> /Eike
>>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
Re: [CDO] reading/writting throughput performances [message #124080 is a reply to message #123651] Fri, 30 May 2008 12:43 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Hi Simon and Eike,

thanks for your feedback, now I know what I could expect in using optimized
implementation, I'll have a try on the hibernate store and see if it is
scaling in a better way.

You gave me many pointers to explain the performances issues but in fact it
seems that the SQL execution is taking so much time (not suprisingly in
fact ;) . My first profile was wrong.

So I'm installing the hibernate store retrieving all the source code from
CVS, and I'm trying to launch the unit tests. I added many jars and
everything gets compiled but most of the tests are failling with "

"
org.hibernate.MappingException: Could not determine type for:
org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType, at
table: cdo_features, for columns: [org.hibernate.mapping.Column(type)]
"

any hint ?

Cédric


Simon McDuff wrote:

> We noticed a performance degradation in the following case:
>
> When we fetch a collection of objects that contains collections that we
> don't want to use. Ex:
>
> Model:
>
> ClassB
> {
> int foo1;
> List childrens1;
> List childrens2;
> List childrens3;
> };
>
> Code:
>
> Resource.contents contains objects of type ClassB.
>
> By fetching instances of classB, we will also fetched some items in the
> list(childrens1, childrens2, childrens3) The problem we had.. is we do not
> know if we want to use it. SO better not to download them.
>
> So In our production(we used our own IStore), we never download any
> objects from collection. I'm working at the moment to put in place all
> feature we used in the current CDO. That one will be part of
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
> with,CDORevisionImpl needs to supports list that are 0 even if
> referenceChunkSize == 0.
>
> It is true that we obtain good performance.
> Worst case :
> 1500 objects /sec (Real fetch from disk. Page that contains the objects,
> wasn't in the cache of the filesystem.)
>
> Best case
> 12 000 objects/Sec (Fetch objects that are already in the case of the
> filesystem)
>
> (These statistics always fetch objects from server to client. The cache
> client isn't used)
>
> We have another optimization one with SmartReadAhead but for now only work
> for UI client. (for now) This is something we will integrate as well in
> CDO. But for now we concentrate on the other things.
>
> I used an Object database. Based on my preliminary test without CDO.
> I compare
>
> Hibernate vs Objectivity/EMF :
> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>
> The worst.. you will get 30 to 240 objects/sec or
> the best... you will get 500 to 4000 objects/sec
>
> Based on your comments... you are getting the worst (with Derby)!! :-)
>
>
> Another comments about insertion.
>
> We found another problem when we insert data(DOn't know if it is still
> true). Resource.Contents is a unique list. Basically each time we insert
> one element, it needs to fetch all the collection to see if we already
> have this element. Basically.. it is time consuming. In our case we are
> not going through this stage to persist our objects... but the objects are
> not accessible through that list.
>
>
>
> If speed is an issue for you!! We (You included :-)) can optimize it. What
> I like is Eike did a really good job doing that framwork and optimizations
> are easy to add. Also you can change your back-end without affecting you
> client side. (Maybe going to an Object database!!) THis was one of the
> purpose of CDO!! :-)
>
>
> Simon
>
>
> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de news:
> 483E9332.6050800@sympedia.de... Hi Cédric,
>
> That sounds interesting!
> Comments inline...
>
>
> Cédric Brun schrieb:
> Hi Eike,
>
> I've been messing around CDO lately and I hacked a few ugly unit-tests
> measuring read/write throughput when I use CDO (RC2).
>
> I'm using an embeded-derby database, two different metamodels (complex one
> - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
> Features)
>
> The test is a "quick and dirty" one so please do not take these figures
> too seriously, I would just like to have your input about the "order of
> magnitude" I should expect or settings affecting seriously these
> performances. I tried both JVM and TCP acceptor but the performances are
> quite similar though JVM is a bit faster.
> Looks like a sign that the NIO socket channels are efficient ,-)
> You used localhost for TCP transport I guess?
>
>
>
> * First case : building a small model (10000 elements) with the simple MM,
> only adding instances in an empty database :
> commiting change on every add I get a 2 objects per second rate.
> commiting changes every 10 adds - I get a 30 objects per second rate.
> Seems to be consistent with the fact that only for commits there is
> remote traffic. And the backend transaction management is another
> overhead. So the impact of the number objects/commit starts with bigger
> transactions.
>
>
> browsing the just commited elements opening a new transaction and getting
> a new Resource instance, I get around 30 000 objets/sec rate just
> iterating thanks to Resource.getAllContents().
> Hehe, this is a sign that client side caching works well:
> All views and transactions of a single session share (and cache) their
> object state. Otherwise I'd expect much smaller values.
> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
> several thousands objects/sec. But the DBStore (which you used) is not
> that optimized.
>
>
> * Second case : I built a big model in the database using the complex
> metamodel. It contains 700 000 elements. The creation went pretty nicely
> (I did not measured it exactly as it was launched during a night, but it
> seems I got around 100 objects/sec rate in writting as I was writting
> every 700 objects.
> Sounds not too bad.
>
>
>
> Once the model is built the derby database is 222 MB (which - I heard - is
> not so big for derby).
> Hmm, I have no extensive experience with Derby.
> To be honest, I'm really no database expert (although I can write simple
> SQL statements).
>
>
> Retrieving the distant resource and calling eAllContents() on it, I get a
> 50 Objects/sec rate at best, which mean my eAllContents() call would take
> 4 hours !
> Currently I'm not sure what exactly eAllContents() does do (iteration
> order and so). There are several CDO features that can have a major
> impact on load rates!
>
> - Collections (xrefs and containment) can be loaded lazily. I don't mean
> the target objects, which are lazy by default anyway, but even the
> target IDs that are in the collections. We call that "reference
> chunking" (but search for a better name is ongoing).
>
> public interface CDOSession extends CDOProtocolSession,
> IContainer<CDOView>
> {
> public int getReferenceChunkSize();
>
> public void setReferenceChunkSize(int referenceChunkSize);
>
>
> - Loading collection elements (target objects) can be batched (the
> current name is even worse)
>
> public interface CDOView extends CDOProtocolView, INotifier
> {
> public int getLoadRevisionCollectionChunkSize();
>
> public void setLoadRevisionCollectionChunkSize(int
> loadRevisionCollectionChunkSize);
>
>
> - One of the most sophisticated feature is automatic model usage
> analyzation. The result are fetch rules that are sent to the server.
> When later objects are loaded from the server, it can answer with
> additional objects that are likely to be needed by the client in the
> near future.
>
> public class CDOViewImpl extends
> org.eclipse.net4j.internal.util.event.Notifier implements CDOView,
> CDOIDProvider, Adapter.Internal
> {
> public CDOFeatureAnalyzer getFeatureAnalyzer()
> {
> return featureAnalyzer;
> }
>
> public void setFeatureAnalyzer(CDOFeatureAnalyzer
> featureAnalyzer)
> {
> this.featureAnalyzer = featureAnalyzer == null ?
> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
> }
>
>
> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
> - Caches can be configured
> - ...
>
>
> Known issues of the DBStore:
> - When in auditing mode updates are always written as complete inserts
> (by design) - When configuring toManyReferences to a value different
> from LIKE_ATTRIBUTES (which is not implemented yet) it is very slow. -
> No (few) prepared statements are used (see
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe others...
>
> Please note that the DBStore was not written by me to compete with
> Hibernate in terms of performance or mapping capabilities. Now that
> Martin and I, well in the end mostly Martin, provide a HibernateStore
> and this HibernateStore gets more and more features I expect that there
> will be a trend away from the DBStore.
>
>
> This is probably linked to the way the mapping to db is done, here's the
> config I used (came from CDO-server example if I recall correctly).
>
>
> <repository name="repo1">
> <property name="overrideUUID"
> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
> <property name="supportingAudits" value="true"/>
> <property name="verifyingRevisions" value="false"/>
> <property name="currentLRUCapacity" value="10000"/>
> I guess this one could be larger.
>
>
> <property name="revisedLRUCapacity" value="100"/>
>
> <store type="db">
> <!-- type: horizontal | vertical | <any
> user-contributed type> --> <mappingStrategy
> type="horizontal">
> <!-- ONE_TABLE_PER_REFERENCE |
> ONE_TABLE_PER_CLASS |
> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
> <property name="toManyReferences"
> value="ONE_TABLE_PER_REFERENCE"/>
>
> <!-- LIKE_ATTRIBUTES |
> LIKE_TO_MANY_REFERENCES --> <property
> name="toOneReferences"
> value="LIKE_ATTRIBUTES"/>
>
> <!-- MODEL | STRATEGY -->
> <property name="mappingPrecedence"
> value="MODEL"/>
> This one is obsolete.
>
>
> </mappingStrategy>
>
> <dbAdapter name="derby-embedded"/>
> <dataSource
> class="org.apache.derby.jdbc.EmbeddedDataSource"
> databaseName="/tmp/cdodb1"
> createDatabase="create"/>
>
> </store>
> </repository>
>
>
>
>
> What do you think about that ? What throughput do you think I should
> expect ? As I said that's very difficult to judge.
> I believe it's more appropriate to compare the actual values with values
> from other measures (other setups, properties, etc. or even other
> products) instead of random expectations. Apologies that I didn't have
> the time so far to provide some reference measures myself. Maybe this
> gets better now that the team starts to grow slowly ;-)
>
>
> What are the main reasons fur such figures ?
> Hmm, I *suspect* you don't like the figures? I can find no evidence your
> assessment ;-)
>
> Ahh,one more note:
> Tracing can also have a significant impact on performance and end-to-end
> throughput. Turn it off by all means. And please make sure that it's
> really turned off, not only invisible (i.e. console is not a target).
>
> Cheers
> /Eike


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #124092 is a reply to message #124080] Fri, 30 May 2008 12:39 Go to previous messageGo to next message
Martin Taal is currently offline Martin TaalFriend
Messages: 5468
Registered: July 2009
Senior Member
Hi Cédric,
Most of the time this exception is thrown because hibernate can't find the class. A common cause is
that the hibernate jar files are located in a separate plugin which can not reach the classes in
other plugins. If you set the eclipse buddy policy of the hibernate plugin to dependent then this
can help.

gr. Martin

Cédric Brun wrote:
> Hi Simon and Eike,
>
> thanks for your feedback, now I know what I could expect in using optimized
> implementation, I'll have a try on the hibernate store and see if it is
> scaling in a better way.
>
> You gave me many pointers to explain the performances issues but in fact it
> seems that the SQL execution is taking so much time (not suprisingly in
> fact ;) . My first profile was wrong.
>
> So I'm installing the hibernate store retrieving all the source code from
> CVS, and I'm trying to launch the unit tests. I added many jars and
> everything gets compiled but most of the tests are failling with "
>
> "
> org.hibernate.MappingException: Could not determine type for:
> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType, at
> table: cdo_features, for columns: [org.hibernate.mapping.Column(type)]
> "
>
> any hint ?
>
> Cédric
>
>
> Simon McDuff wrote:
>
>> We noticed a performance degradation in the following case:
>>
>> When we fetch a collection of objects that contains collections that we
>> don't want to use. Ex:
>>
>> Model:
>>
>> ClassB
>> {
>> int foo1;
>> List childrens1;
>> List childrens2;
>> List childrens3;
>> };
>>
>> Code:
>>
>> Resource.contents contains objects of type ClassB.
>>
>> By fetching instances of classB, we will also fetched some items in the
>> list(childrens1, childrens2, childrens3) The problem we had.. is we do not
>> know if we want to use it. SO better not to download them.
>>
>> So In our production(we used our own IStore), we never download any
>> objects from collection. I'm working at the moment to put in place all
>> feature we used in the current CDO. That one will be part of
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>> with,CDORevisionImpl needs to supports list that are 0 even if
>> referenceChunkSize == 0.
>>
>> It is true that we obtain good performance.
>> Worst case :
>> 1500 objects /sec (Real fetch from disk. Page that contains the objects,
>> wasn't in the cache of the filesystem.)
>>
>> Best case
>> 12 000 objects/Sec (Fetch objects that are already in the case of the
>> filesystem)
>>
>> (These statistics always fetch objects from server to client. The cache
>> client isn't used)
>>
>> We have another optimization one with SmartReadAhead but for now only work
>> for UI client. (for now) This is something we will integrate as well in
>> CDO. But for now we concentrate on the other things.
>>
>> I used an Object database. Based on my preliminary test without CDO.
>> I compare
>>
>> Hibernate vs Objectivity/EMF :
>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>
>> The worst.. you will get 30 to 240 objects/sec or
>> the best... you will get 500 to 4000 objects/sec
>>
>> Based on your comments... you are getting the worst (with Derby)!! :-)
>>
>>
>> Another comments about insertion.
>>
>> We found another problem when we insert data(DOn't know if it is still
>> true). Resource.Contents is a unique list. Basically each time we insert
>> one element, it needs to fetch all the collection to see if we already
>> have this element. Basically.. it is time consuming. In our case we are
>> not going through this stage to persist our objects... but the objects are
>> not accessible through that list.
>>
>>
>>
>> If speed is an issue for you!! We (You included :-)) can optimize it. What
>> I like is Eike did a really good job doing that framwork and optimizations
>> are easy to add. Also you can change your back-end without affecting you
>> client side. (Maybe going to an Object database!!) THis was one of the
>> purpose of CDO!! :-)
>>
>>
>> Simon
>>
>>
>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de news:
>> 483E9332.6050800@sympedia.de... Hi Cédric,
>>
>> That sounds interesting!
>> Comments inline...
>>
>>
>> Cédric Brun schrieb:
>> Hi Eike,
>>
>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>> measuring read/write throughput when I use CDO (RC2).
>>
>> I'm using an embeded-derby database, two different metamodels (complex one
>> - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>> Features)
>>
>> The test is a "quick and dirty" one so please do not take these figures
>> too seriously, I would just like to have your input about the "order of
>> magnitude" I should expect or settings affecting seriously these
>> performances. I tried both JVM and TCP acceptor but the performances are
>> quite similar though JVM is a bit faster.
>> Looks like a sign that the NIO socket channels are efficient ,-)
>> You used localhost for TCP transport I guess?
>>
>>
>>
>> * First case : building a small model (10000 elements) with the simple MM,
>> only adding instances in an empty database :
>> commiting change on every add I get a 2 objects per second rate.
>> commiting changes every 10 adds - I get a 30 objects per second rate.
>> Seems to be consistent with the fact that only for commits there is
>> remote traffic. And the backend transaction management is another
>> overhead. So the impact of the number objects/commit starts with bigger
>> transactions.
>>
>>
>> browsing the just commited elements opening a new transaction and getting
>> a new Resource instance, I get around 30 000 objets/sec rate just
>> iterating thanks to Resource.getAllContents().
>> Hehe, this is a sign that client side caching works well:
>> All views and transactions of a single session share (and cache) their
>> object state. Otherwise I'd expect much smaller values.
>> With his ObjectivityStore implementation Simon (cc'ed) reached rates of
>> several thousands objects/sec. But the DBStore (which you used) is not
>> that optimized.
>>
>>
>> * Second case : I built a big model in the database using the complex
>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>> (I did not measured it exactly as it was launched during a night, but it
>> seems I got around 100 objects/sec rate in writting as I was writting
>> every 700 objects.
>> Sounds not too bad.
>>
>>
>>
>> Once the model is built the derby database is 222 MB (which - I heard - is
>> not so big for derby).
>> Hmm, I have no extensive experience with Derby.
>> To be honest, I'm really no database expert (although I can write simple
>> SQL statements).
>>
>>
>> Retrieving the distant resource and calling eAllContents() on it, I get a
>> 50 Objects/sec rate at best, which mean my eAllContents() call would take
>> 4 hours !
>> Currently I'm not sure what exactly eAllContents() does do (iteration
>> order and so). There are several CDO features that can have a major
>> impact on load rates!
>>
>> - Collections (xrefs and containment) can be loaded lazily. I don't mean
>> the target objects, which are lazy by default anyway, but even the
>> target IDs that are in the collections. We call that "reference
>> chunking" (but search for a better name is ongoing).
>>
>> public interface CDOSession extends CDOProtocolSession,
>> IContainer<CDOView>
>> {
>> public int getReferenceChunkSize();
>>
>> public void setReferenceChunkSize(int referenceChunkSize);
>>
>>
>> - Loading collection elements (target objects) can be batched (the
>> current name is even worse)
>>
>> public interface CDOView extends CDOProtocolView, INotifier
>> {
>> public int getLoadRevisionCollectionChunkSize();
>>
>> public void setLoadRevisionCollectionChunkSize(int
>> loadRevisionCollectionChunkSize);
>>
>>
>> - One of the most sophisticated feature is automatic model usage
>> analyzation. The result are fetch rules that are sent to the server.
>> When later objects are loaded from the server, it can answer with
>> additional objects that are likely to be needed by the client in the
>> near future.
>>
>> public class CDOViewImpl extends
>> org.eclipse.net4j.internal.util.event.Notifier implements CDOView,
>> CDOIDProvider, Adapter.Internal
>> {
>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>> {
>> return featureAnalyzer;
>> }
>>
>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>> featureAnalyzer)
>> {
>> this.featureAnalyzer = featureAnalyzer == null ?
>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>> }
>>
>>
>> - There's a SmartReadAheadThread (if you're curious, please ask Simon).
>> - Caches can be configured
>> - ...
>>
>>
>> Known issues of the DBStore:
>> - When in auditing mode updates are always written as complete inserts
>> (by design) - When configuring toManyReferences to a value different
>> from LIKE_ATTRIBUTES (which is not implemented yet) it is very slow. -
>> No (few) prepared statements are used (see
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe others...
>>
>> Please note that the DBStore was not written by me to compete with
>> Hibernate in terms of performance or mapping capabilities. Now that
>> Martin and I, well in the end mostly Martin, provide a HibernateStore
>> and this HibernateStore gets more and more features I expect that there
>> will be a trend away from the DBStore.
>>
>>
>> This is probably linked to the way the mapping to db is done, here's the
>> config I used (came from CDO-server example if I recall correctly).
>>
>>
>> <repository name="repo1">
>> <property name="overrideUUID"
>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>> <property name="supportingAudits" value="true"/>
>> <property name="verifyingRevisions" value="false"/>
>> <property name="currentLRUCapacity" value="10000"/>
>> I guess this one could be larger.
>>
>>
>> <property name="revisedLRUCapacity" value="100"/>
>>
>> <store type="db">
>> <!-- type: horizontal | vertical | <any
>> user-contributed type> --> <mappingStrategy
>> type="horizontal">
>> <!-- ONE_TABLE_PER_REFERENCE |
>> ONE_TABLE_PER_CLASS |
>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>> <property name="toManyReferences"
>> value="ONE_TABLE_PER_REFERENCE"/>
>>
>> <!-- LIKE_ATTRIBUTES |
>> LIKE_TO_MANY_REFERENCES --> <property
>> name="toOneReferences"
>> value="LIKE_ATTRIBUTES"/>
>>
>> <!-- MODEL | STRATEGY -->
>> <property name="mappingPrecedence"
>> value="MODEL"/>
>> This one is obsolete.
>>
>>
>> </mappingStrategy>
>>
>> <dbAdapter name="derby-embedded"/>
>> <dataSource
>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>> databaseName="/tmp/cdodb1"
>> createDatabase="create"/>
>>
>> </store>
>> </repository>
>>
>>
>>
>>
>> What do you think about that ? What throughput do you think I should
>> expect ? As I said that's very difficult to judge.
>> I believe it's more appropriate to compare the actual values with values
>> from other measures (other setups, properties, etc. or even other
>> products) instead of random expectations. Apologies that I didn't have
>> the time so far to provide some reference measures myself. Maybe this
>> gets better now that the team starts to grow slowly ;-)
>>
>>
>> What are the main reasons fur such figures ?
>> Hmm, I *suspect* you don't like the figures? I can find no evidence your
>> assessment ;-)
>>
>> Ahh,one more note:
>> Tracing can also have a significant impact on performance and end-to-end
>> throughput. Turn it off by all means. And please make sure that it's
>> really turned off, not only invisible (i.e. console is not a target).
>>
>> Cheers
>> /Eike
>


--

With Regards, Martin Taal

Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
Re: [CDO] reading/writting throughput performances [message #124124 is a reply to message #123787] Fri, 30 May 2008 13:08 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
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Performance problem with resource.content
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D234839
"Eike Stepper" <stepper@sympedia.de> a =C3=A9crit dans le message de =
news: g1mp23$pu1$4@build.eclipse.org...
Guys,

Comments inline...


Simon McDuff schrieb:=20
We noticed a performance degradation in the following case:
=20
When we fetch a collection of objects that contains collections that =
we don't want to use.=20
Ex:
=20
Model:
=20
ClassB
{
int foo1;
List childrens1;
List childrens2;
List childrens3;
};
=20
Code:

Resource.contents contains objects of type ClassB.
=20
By fetching instances of classB, we will also fetched some items in =
the list(childrens1, childrens2, childrens3) The problem we had.. is we =
do not know if we want to use it. SO better not to download them.

So In our production(we used our own IStore), we never download any =
objects from collection.=20
I'm working at the moment to put in place all feature we used in the =
current CDO.
That one will be part of=20
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477. To begin =
with,CDORevisionImpl needs to supports list that are 0 even if =
referenceChunkSize =3D=3D 0.
=20
It is true that we obtain good performance.
Worst case :
1500 objects /sec (Real fetch from disk. Page that contains the =
objects, wasn't in the cache of the filesystem.)=20
=20
Best case=20
12 000 objects/Sec (Fetch objects that are already in the case of =
the filesystem)
=20
(These statistics always fetch objects from server to client. The =
cache client isn't used)
=20
We have another optimization one with SmartReadAhead but for now =
only work for UI client. (for now) This is something we will integrate =
as well in CDO. But for now we concentrate on the other things.
=20
I used an Object database. Based on my preliminary test without CDO.
I compare
=20
Hibernate vs Objectivity/EMF :=20
Objectivity/EMF is around 3 to 50 times faster than Hibernate.
=20
The worst.. you will get 30 to 240 objects/sec or
the best... you will get 500 to 4000 objects/sec
=20
Based on your comments... you are getting the worst (with Derby)!! =
:-)

And with the DBStore!!
I'd really like to encourage you to use the HibernateStore.=20
It is much younger than the DBStore but Hibernate itself should do a =
much better job on mapping than the DBStore.

That said, the DBStore will, for multiple reasons, never cease to =
exist in CDO.



=20
Another comments about insertion.
=20
We found another problem when we insert data(DOn't know if it is =
still true). Resource.Contents is a unique list. Basically each time we =
insert one element, it needs to fetch all the collection to see if we =
already have this element. Basically.. it is time consuming. In our case =
we are not going through this stage to persist our objects... but the =
objects are not accessible through that list.

I was not aware of this. Sounds as if we should offer an alternative =
implementation for Resource.Contents.
Could you please open a Bugzilla to discuss/track this?





If speed is an issue for you!! We (You included :-)) can optimize =
it. What I like is Eike did a really good job doing that framwork and =
optimizations are easy to add.
Also you can change your back-end without affecting you client side. =
(Maybe going to an Object database!!)
THis was one of the purpose of CDO!! :-)
Thank you ;-)
Indeed, CDO was intended to focus of the protocol aspects, the =
repository and the client side addition to the EMF concepts.
I feel that this will become clearer the more IStore implementations =
we get that depend on mature 3rd party code for the mapping part.

Cheers
/Eike





Simon


"Eike Stepper" <stepper@sympedia.de> a =C3=A9crit dans le message =
de news: 483E9332.6050800@sympedia.de...
Hi C=C3=A9dric,

That sounds interesting!
Comments inline...


C=C3=A9dric Brun schrieb:=20
Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex =
one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 =
Features)

The test is a "quick and dirty" one so please do not take these figures =
too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
Looks like a sign that the NIO socket channels are efficient ,-)
You used localhost for TCP transport I guess?


* First case : building a small model (10000 elements) with the simple =
MM,
only adding instances in an empty database :=20
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
Seems to be consistent with the fact that only for commits there is =
remote traffic.
And the backend transaction management is another overhead.
So the impact of the number objects/commit starts with bigger =
transactions.


browsing the just commited elements opening a new transaction and =
getting a
new Resource instance, I get around 30 000 objets/sec rate just =
iterating
thanks to Resource.getAllContents().
Hehe, this is a sign that client side caching works well:
All views and transactions of a single session share (and cache) =
their object state.
Otherwise I'd expect much smaller values.
With his ObjectivityStore implementation Simon (cc'ed) reached =
rates of several thousands objects/sec.
But the DBStore (which you used) is not that optimized.


* Second case : I built a big model in the database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely =
(I
did not measured it exactly as it was launched during a night, but it =
seems
I got around 100 objects/sec rate in writting as I was writting every =
700
objects.
Sounds not too bad.


Once the model is built the derby database is 222 MB (which - I heard - =
is
not so big for derby).
Hmm, I have no extensive experience with Derby.
To be honest, I'm really no database expert (although I can write =
simple SQL statements).


Retrieving the distant resource and calling eAllContents() on it, I get =
a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
Currently I'm not sure what exactly eAllContents() does do (iteration =
order and so).
There are several CDO features that can have a major impact on =
load rates!

- Collections (xrefs and containment) can be loaded lazily. I =
don't mean the target objects, which are lazy by default anyway, but =
even the target IDs that are in the collections. We call that "reference =
chunking" (but search for a better name is ongoing).

public interface CDOSession extends CDOProtocolSession, =
IContainer<CDOView>
{
public int getReferenceChunkSize();

public void setReferenceChunkSize(int referenceChunkSize); =
=20


- Loading collection elements (target objects) can be batched (the =
current name is even worse)

public interface CDOView extends CDOProtocolView, INotifier
{
public int getLoadRevisionCollectionChunkSize();

public void setLoadRevisionCollectionChunkSize(int =
loadRevisionCollectionChunkSize); =20


- One of the most sophisticated feature is automatic model usage =
analyzation. The result are fetch rules that are sent to the server. =
When later objects are loaded from the server, it can answer with =
additional objects that are likely to be needed by the client in the =
near future.

public class CDOViewImpl extends =
org.eclipse.net4j.internal.util.event.Notifier implements CDOView, =
CDOIDProvider, Adapter.Internal
{
public CDOFeatureAnalyzer getFeatureAnalyzer()
{
return featureAnalyzer;
}

public void setFeatureAnalyzer(CDOFeatureAnalyzer =
featureAnalyzer)
{
this.featureAnalyzer =3D featureAnalyzer =3D=3D null ? =
CDOFeatureAnalyzer.NOOP : featureAnalyzer;
} =20


- There's a SmartReadAheadThread (if you're curious, please ask =
Simon).
- Caches can be configured
- ...


Known issues of the DBStore:
- When in auditing mode updates are always written as complete =
inserts (by design)
- When configuring toManyReferences to a value different from =
LIKE_ATTRIBUTES (which is not implemented yet) it is very slow.
- No (few) prepared statements are used (see =
https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487)
- Maybe others...

Please note that the DBStore was not written by me to compete with =
Hibernate in terms of performance or mapping capabilities.
Now that Martin and I, well in the end mostly Martin, provide a =
HibernateStore and this HibernateStore gets more and more features I =
expect that there will be a trend away from the DBStore.=20


This is probably linked to the way the mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


<repository name=3D"repo1">
<property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
<property name=3D"supportingAudits" value=3D"true"/>
<property name=3D"verifyingRevisions" value=3D"false"/>
<property name=3D"currentLRUCapacity" value=3D"10000"/>
I guess this one could be larger.


<property name=3D"revisedLRUCapacity" value=3D"100"/>
=20
<store type=3D"db">
<!-- type: horizontal | vertical | <any =
user-contributed type> -->
<mappingStrategy type=3D"horizontal">
<!-- ONE_TABLE_PER_REFERENCE | =
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
<property name=3D"toManyReferences" =
value=3D"ONE_TABLE_PER_REFERENCE"/>

<!-- LIKE_ATTRIBUTES | =
LIKE_TO_MANY_REFERENCES -->
<property name=3D"toOneReferences" =
value=3D"LIKE_ATTRIBUTES"/>
=20
<!-- MODEL | STRATEGY -->
<property name=3D"mappingPrecedence" =
value=3D"MODEL"/>
This one is obsolete.


</mappingStrategy>
=20
<dbAdapter name=3D"derby-embedded"/>
<dataSource =
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"=20
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/>

</store>
</repository>




What do you think about that ? What throughput do you think I should
expect ? As I said that's very difficult to judge.
I believe it's more appropriate to compare the actual values with =
values from other measures (other setups, properties, etc. or even other =
products) instead of random expectations.
Apologies that I didn't have the time so far to provide some =
reference measures myself. Maybe this gets better now that the team =
starts to grow slowly ;-)


What are the main reasons fur such figures ?
Hmm, I *suspect* you don't like the figures? I can find no evidence =
your assessment ;-)

Ahh,one more note:
Tracing can also have a significant impact on performance and =
end-to-end throughput.
Turn it off by all means. And please make sure that it's really =
turned off, not only invisible (i.e. console is not a target).

Cheers
/Eike



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charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

=EF=BB=BF<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<META http-equiv=3DContent-Type content=3Dtext/html;charset=3DUTF-8>
<META content=3D"MSHTML 6.00.6000.16608" name=3DGENERATOR></HEAD>
<BODY text=3D#000000 bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Performance problem with=20
resource.content</FONT></DIV>
<DIV><FONT face=3DArial size=3D2><A=20
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D234839">https://b=
ugs.eclipse.org/bugs/show_bug.cgi?id=3D234839</A></FONT></DIV >
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Eike Stepper" &lt;<A=20
href=3D"mailto:stepper@sympedia.de">stepper@sympedia.de</A>&gt; a =
=C3=A9crit dans le=20
message de news: <A=20
=
href=3D"mailto:g1mp23$pu1$4@build.eclipse.org">g1mp23$pu1$4@build.eclipse=
..org</A>...</DIV>Guys,<BR><BR>Comments=20
inline...<BR><BR><BR>Simon McDuff schrieb:=20
<BLOCKQUOTE cite=3Dmid:g1mkji$h5d$1@build.eclipse.org type=3D"cite">
<META content=3D"MSHTML 6.00.6000.16608" name=3DGENERATOR>
<DIV>We noticed a performance degradation in the following=20
case:<BR>&nbsp;<BR>When we fetch a collection of objects that =
contains=20
collections that we don't want to use.=20
<BR>Ex:<BR>&nbsp;<BR>Model:<BR>&nbsp;<BR>ClassB <BR>{<BR>&nbsp; int=20
foo1;<BR>&nbsp; List childrens1;<BR>&nbsp; List =
childrens2;<BR>&nbsp; List=20
childrens3;<BR>};<BR>&nbsp;<BR>Code:</DIV>
<DIV><BR>Resource.contents contains objects of type =
ClassB.<BR>&nbsp;<BR>By=20
fetching instances of classB, we will also fetched some items in the =

list(childrens1, childrens2, childrens3)&nbsp;<FONT face=3D"Courier =
New"><FONT=20
color=3D#000000>The problem we had.. is we do not know if we want to =
use it.=20
SO better not to download them.</FONT></FONT></DIV>
<DIV><BR><FONT face=3D"Courier New" color=3D#000000>So In our =
production(we used=20
our own IStore), we never download any objects from collection.=20
</FONT><BR><FONT face=3D"Courier New" color=3D#000000>I'm working at =
the moment=20
to put in place all feature we used in the current =
CDO.</FONT><BR><FONT=20
face=3D"Courier New" color=3D#000000>That one will be part of =
</FONT><BR><A=20
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477" =
target=3D_blank=20
moz-do-not-send=3D"true"><FONT=20
=
color=3D#0068cf>https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214477</F=
ONT></A>.=20
To begin with,CDORevisionImpl needs to supports list that are 0 even =
if=20
<FONT face=3D"Courier New" color=3D#000000>referenceChunkSize =3D=3D =

0.</FONT><BR>&nbsp;<BR><FONT face=3D"Courier New" color=3D#000000>It =
is true=20
that we obtain good performance.</FONT><BR><FONT face=3D"Courier =
New"=20
color=3D#000000>Worst case :</FONT><BR><FONT face=3D"Courier New"=20
color=3D#000000>1500 objects /sec (Real fetch from&nbsp;disk. Page =
that=20
contains the objects, wasn't in the cache of the=20
filesystem.)&nbsp;</FONT><BR>&nbsp;<BR><FONT face=3D"Courier New"=20
color=3D#000000>Best case </FONT><BR><FONT face=3D"Courier New" =
color=3D#000000>12=20
000 objects/Sec (Fetch objects that are already in the case of the=20
filesystem)</FONT><BR>&nbsp;<BR>(These statistics always fetch =
objects from=20
server to client. The cache client isn't used)<BR>&nbsp;<BR><FONT=20
face=3D"Courier New" color=3D#000000>We have another optimization =
one with=20
SmartReadAhead but for now only work for UI client. (for now)&nbsp; =
This is=20
something we will integrate as well in CDO. But for now we =
concentrate on=20
the other things.</FONT><BR>&nbsp;<BR><FONT face=3D"Courier New"=20
color=3D#000000>I used an Object database. Based on my preliminary =
test=20
without CDO.</FONT><BR><FONT face=3D"Courier New" color=3D#000000>I=20
compare</FONT><BR>&nbsp;<BR><FONT face=3D"Courier New" =
color=3D#000000>Hibernate=20
vs </FONT><FONT face=3D"Courier New" color=3D#000000>Objectivity/EMF =

:&nbsp;</FONT><BR><FONT face=3D"Courier New" =
color=3D#000000>Objectivity/EMF is=20
around 3 to 50 times faster than =
Hibernate.</FONT><BR>&nbsp;<BR><FONT=20
face=3D"Courier New" color=3D#000000>The worst.. you will get 30 to =
240=20
objects/sec or</FONT><BR><FONT face=3D"Courier New" =
color=3D#000000>the best...=20
you will get 500 to 4000 objects/sec</FONT><BR>&nbsp;<BR><FONT=20
face=3D"Courier New" color=3D#000000>Based on your comments... you =
are getting=20
the worst (with Derby)!! :-)</FONT><BR></DIV></BLOCKQUOTE>And with =
the=20
DBStore!!<BR>I'd really like to encourage you to use the =
HibernateStore.=20
<BR>It is much younger than the DBStore but Hibernate itself should do =
a much=20
better job on mapping than the DBStore.<BR><BR>That said, the DBStore =
will,=20
for multiple reasons, never cease to exist in CDO.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1mkji$h5d$1@build.eclipse.org type=3D"cite">
<DIV><BR>&nbsp;<BR>Another comments about insertion.<BR>&nbsp;<BR>We =
found=20
another problem when we insert data(DOn't know if it is still true). =

Resource.Contents is&nbsp;a unique list. Basically each time we =
insert one=20
element, it needs to fetch all the collection to see if we already =
have this=20
element. Basically.. it is time consuming. In our case we are not =
going=20
through this stage to persist our objects... but the objects are not =

accessible through that list.<BR></DIV></BLOCKQUOTE>I was not aware =
of this.=20
Sounds as if we should offer an alternative implementation for=20
Resource.Contents.<BR>Could you please open a Bugzilla to =
discuss/track=20
this?<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1mkji$h5d$1@build.eclipse.org type=3D"cite">
<DIV>&nbsp;</DIV>
<DIV>&nbsp;</DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>If speed is an issue for you!! We =
(You included=20
:-)) can optimize it. What I like is Eike did a really good job =
doing that=20
framwork and optimizations are easy to add.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Also you can change your back-end =
without=20
affecting you client side. (Maybe going to an Object=20
database!!)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>THis was one of the purpose of =
CDO!!=20
:-)</FONT></DIV></BLOCKQUOTE>Thank you ;-)<BR>Indeed, CDO was =
intended to=20
focus of the protocol aspects, the repository and the client side =
addition to=20
the EMF concepts.<BR>I feel that this will become clearer the more =
IStore=20
implementations we get that depend on mature 3rd party code for the =
mapping=20
part.<BR><BR>Cheers<BR>/Eike<BR><BR><BR>
<BLOCKQUOTE cite=3Dmid:g1mkji$h5d$1@build.eclipse.org type=3D"cite">
<DIV>&nbsp;</DIV>
<DIV><BR>Simon<BR><BR></DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: rgb(0,0,0) 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Eike Stepper" &lt;<A href=3D"mailto:stepper@sympedia.de"=20
moz-do-not-send=3D"true">stepper@sympedia.de</A>&gt; a =C3=A9crit =
dans le message=20
de news: <A href=3D"mailto:483E9332.6050800@sympedia.de"=20
=
moz-do-not-send=3D"true">483E9332.6050800@sympedia.de</A>...</DIV>Hi=20
C=C3=A9dric,<BR><BR>That sounds interesting!<BR>Comments=20
inline...<BR><BR><BR>C=C3=A9dric Brun schrieb:=20
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Hi Eike,

I've been messing around CDO lately and I hacked a few ugly unit-tests
measuring read/write throughput when I use CDO (RC2).

I'm using an embeded-derby database, two different metamodels (complex =
one -
250 EClassifiers/300 features and a simple one - 1 Classifier/3 =
Features)

The test is a "quick and dirty" one so please do not take these figures =
too
seriously, I would just like to have your input about the "order of
magnitude" I should expect or settings affecting seriously these
performances. I tried both JVM and TCP acceptor but the performances are
quite similar though JVM is a bit faster.
</PRE></BLOCKQUOTE>Looks like a sign that the NIO socket channels are=20
efficient ,-)<BR>You used localhost for TCP transport I =
guess?<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">* First case : building a small model =
(10000 elements) with the simple MM,
only adding instances in an empty database :=20
commiting change on every add I get a 2 objects per second rate.
commiting changes every 10 adds - I get a 30 objects per second rate.
</PRE></BLOCKQUOTE>Seems to be consistent with the fact that only for=20
commits there is remote traffic.<BR>And the backend transaction =
management=20
is another overhead.<BR>So the impact of the number objects/commit =
starts=20
with bigger transactions.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">browsing the just commited elements opening =
a new transaction and getting a
new Resource instance, I get around 30 000 objets/sec rate just =
iterating
thanks to Resource.getAllContents().
</PRE></BLOCKQUOTE>Hehe, this is a sign that client side caching works =

well:<BR>All views and transactions of a single session share (and =
cache)=20
their object state.<BR>Otherwise I'd expect much smaller =
values.<BR>With=20
his ObjectivityStore implementation Simon (cc'ed) reached rates of =
several=20
thousands objects/sec.<BR>But the DBStore (which you used) is not =
that=20
optimized.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">* Second case : I built a big model in the =
database using the complex
metamodel. It contains 700 000 elements. The creation went pretty nicely =
(I
did not measured it exactly as it was launched during a night, but it =
seems
I got around 100 objects/sec rate in writting as I was writting every =
700
objects.
</PRE></BLOCKQUOTE>Sounds not too bad.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Once the model is built the derby database =
is 222 MB (which - I heard - is
not so big for derby).
</PRE></BLOCKQUOTE>Hmm, I have no extensive experience with =
Derby.<BR>To=20
be honest, I'm really no database expert (although I can write =
simple SQL=20
statements).<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">Retrieving the distant resource and calling =
eAllContents() on it, I get a 50
Objects/sec rate at best, which mean my eAllContents() call would take 4
hours !
</PRE></BLOCKQUOTE>Currently I'm not sure what exactly eAllContents()=20
does do (iteration order and so).<BR>There are several CDO =
features that=20
can have a major impact on load rates!<BR><BR>- Collections (xrefs =
and=20
containment) can be loaded lazily. I don't mean the target =
objects, which=20
are lazy by default anyway, but even the target IDs that are in =
the=20
collections. We call that "reference chunking" (but search for a =
better=20
name is ongoing).<BR>
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=
color=3D#7f0055><B>public&nbsp;interface&nbsp;</B ></FONT><FONT=20
color=3D#000000>CDOSession&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
=
color=3D#000000> CDOProtocolSession,&nbsp;IContainer&lt;CDOView&g t; </FONT>=
<BR><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>getReferenceChunkSize</FONT><FONT=20
color=3D#000000>()</FONT><FONT =
color=3D#000000>;</FONT><BR><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setReferenceChunkSize</FONT><FONT=20
color=3D#000000>(</FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>referenceChunkSize</FONT><FONT=20
color=3D#000000>)</FONT><FONT =
color=3D#000000>;</FONT></CODE> </TD><!-- end source code =
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=3D=3D=3D=3D=3D=3D -->-=20
Loading collection elements (target objects) can be batched (the =
current=20
name is even worse)<BR>
<STYLE type=3Dtext/css>
<!--code { font-family: Courier New, Courier; font-size: 10pt; =
margin: 0px; }-->
</STYLE>
<!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
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<DIV class=3Djava align=3Dleft>
<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff =
border=3D0>
<TBODY>
<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
=
color=3D#7f0055><B>public&nbsp;interface&nbsp;</B ></FONT><FONT=20
color=3D#000000>CDOView&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
=
color=3D#000000>CDOProtocolView,&nbsp;INotifier</FONT> <BR><FONT=20
color=3D#000000>{</FONT><BR><FONT color=3D#ffffff>&nbsp; =
</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
=
color=3D#000000>getLoadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>()</FONT><FONT =
color=3D#000000>;</FONT><BR><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
=
color=3D#000000>setLoadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>(</FONT><FONT=20
color=3D#7f0055><B>int&nbsp;</B></FONT><FONT=20
color=3D#000000>loadRevisionCollectionChunkSize</FONT><FONT=20
color=3D#000000>)</FONT><FONT =
color=3D#000000>;</FONT></CODE> </TD><!-- end source code =
--></TR></TBODY></TABLE></DIV><!-- =3D END of automatically =
generated HTML code =3D --><!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D --><BR>-=20
One of the most sophisticated feature is automatic model usage=20
analyzation. The result are fetch rules that are sent to the =
server. When=20
later objects are loaded from the server, it can answer with =
additional=20
objects that are likely to be needed by the client in the near =
future.<BR>
<STYLE type=3Dtext/css>
<!--code { font-family: Courier New, Courier; font-size: 10pt; =
margin: 0px; }-->
</STYLE>
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
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converted code =3D --><!-- =3D Java2Html Converter 5.0 [2006-02-26] by =
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<DIV class=3Djava align=3Dleft>
<TABLE cellSpacing=3D0 cellPadding=3D3 bgColor=3D#ffffff =
border=3D0>
<TBODY>
<TR><!-- start source code -->
<TD vAlign=3Dtop noWrap align=3Dleft><CODE><FONT=20
color=3D#7f0055><B>public&nbsp;class&nbsp;</B></FONT ><FONT=20
color=3D#000000>CDOViewImpl&nbsp;</FONT><FONT=20
color=3D#7f0055><B>extends&nbsp;</B></FONT><FONT=20
=
color=3D#000000>org.eclipse.net4j.internal.util.event.Notifier&nbsp; </FON=
T><FONT=20
color=3D#7f0055><B>implements&nbsp;</B></FONT><FONT=20
color=3D#000000>CDOView,&nbsp;CDOIDProvider,</FONT> <FONT=20
color=3D#000000>Adapter.Internal</FONT><BR><FONT=20
color=3D#000000>{</FONT><BR><FONT color=3D#ffffff>&nbsp; =
</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
=
color=3D#000000>CDOFeatureAnalyzer&nbsp;getFeatureAnalyzer </FONT><FONT=20
color=3D#000000>()</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>return&nbsp;</B></FONT><FONT=20
color=3D#000000>featureAnalyzer;</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>}</FONT><BR><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#7f0055><B>public&nbsp;</B></FONT><FONT=20
color=3D#7f0055><B>void&nbsp;</B></FONT><FONT=20
color=3D#000000>setFeatureAnalyzer</FONT><FONT=20
color=3D#000000>(</FONT><FONT=20
=
color=3D#000000>CDOFeatureAnalyzer&nbsp;featureAnalyzer </FONT><FONT=20
color=3D#000000>)</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT=20
color=3D#000000>{</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;&nbsp;&nbsp;</FONT ><FONT=20
color=3D#7f0055><B>this</B></FONT><FONT=20
=
color=3D#000000> .featureAnalyzer&nbsp;=3D&nbsp;featureAnalyzer&n bsp;=3D=3D=
&nbsp;</FONT><FONT=20
color=3D#7f0055><B>null&nbsp;</B></FONT><FONT=20
=
color=3D#000000> ?&nbsp;CDOFeatureAnalyzer.NOOP&nbsp;:&nbsp;featu reAnalyze=
r;</FONT><BR><FONT=20
color=3D#ffffff>&nbsp;&nbsp;</FONT><FONT =
color=3D#000000>}</FONT></CODE>=20
</TD><!-- end source code --></TR></TBODY></TABLE></DIV><!-- =
=3D END of automatically generated HTML code =3D --><!-- =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D --><BR>-=20
There's a SmartReadAheadThread (if you're curious, please ask =
Simon).<BR>-=20
Caches can be configured<BR>- ...<BR><BR><BR>Known issues of the=20
DBStore:<BR>- When in auditing mode updates are always written as =
complete=20
inserts (by design)<BR>- When configuring toManyReferences to a =
value=20
different from LIKE_ATTRIBUTES (which is not implemented yet) it =
is very=20
slow.<BR>- No (few) prepared statements are used (see <A=20
class=3Dmoz-txt-link-freetext=20
href=3D"https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D214487"=20
=
moz-do-not-send=3D"true">https://bugs.eclipse.org/bugs/show_bug.cgi?id=3D=
214487</A>)<BR>-=20
Maybe others...<BR><BR>Please note that the DBStore was not =
written by me=20
to compete with Hibernate in terms of performance or mapping=20
capabilities.<BR>Now that Martin and I, well in the end mostly =
Martin,=20
provide a HibernateStore and this HibernateStore gets more and =
more=20
features I expect that there will be a trend away from the =
DBStore.=20
<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">This is probably linked to the way the =
mapping to db is done, here's the
config I used (came from CDO-server example if I recall correctly).


&lt;repository name=3D"repo1"&gt;
&lt;property name=3D"overrideUUID"
value=3D"1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/&gt;
&lt;property name=3D"supportingAudits" =
value=3D"true"/&gt;
&lt;property name=3D"verifyingRevisions" =
value=3D"false"/&gt;
&lt;property name=3D"currentLRUCapacity" =
value=3D"10000"/&gt;
</PRE></BLOCKQUOTE>I guess this one could be larger.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D""> &lt;property =
name=3D"revisedLRUCapacity" value=3D"100"/&gt;
=20
&lt;store type=3D"db"&gt;
&lt;!-- type: horizontal | vertical | &lt;any =
user-contributed type&gt; --&gt;
&lt;mappingStrategy type=3D"horizontal"&gt;
&lt;!-- ONE_TABLE_PER_REFERENCE | =
ONE_TABLE_PER_CLASS |
ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES =
--&gt;
&lt;property name=3D"toManyReferences" =
value=3D"ONE_TABLE_PER_REFERENCE"/&gt;

&lt;!-- LIKE_ATTRIBUTES | =
LIKE_TO_MANY_REFERENCES --&gt;
&lt;property name=3D"toOneReferences" =
value=3D"LIKE_ATTRIBUTES"/&gt;
=20
&lt;!-- MODEL | STRATEGY --&gt;
&lt;property name=3D"mappingPrecedence" =
value=3D"MODEL"/&gt;
</PRE></BLOCKQUOTE>This one is obsolete.<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D""> =
&lt;/mappingStrategy&gt;
=20
&lt;dbAdapter name=3D"derby-embedded"/&gt;
&lt;dataSource =
class=3D"org.apache.derby.jdbc.EmbeddedDataSource"=20
databaseName=3D"/tmp/cdodb1"
createDatabase=3D"create"/&gt;

&lt;/store&gt;
&lt;/repository&gt;




What do you think about that ? What throughput do you think I should
expect ? </PRE></BLOCKQUOTE>As I said that's very difficult to=20
judge.<BR>I believe it's more appropriate to compare the actual =
values=20
with values from other measures (other setups, properties, etc. or =
even=20
other products) instead of random expectations.<BR>Apologies that =
I didn't=20
have the time so far to provide some reference measures myself. =
Maybe this=20
gets better now that the team starts to grow slowly ;-)<BR><BR>
<BLOCKQUOTE cite=3Dmid:g1lvjh$jd7$1@build.eclipse.org =
type=3D"cite"><PRE wrap=3D"">What are the main reasons fur such figures =
?
</PRE></BLOCKQUOTE>Hmm, I *suspect* you don't like the figures? I can=20
find no evidence your assessment ;-)<BR><BR>Ahh,one more =
note:<BR>Tracing=20
can also have a significant impact on performance and end-to-end=20
throughput.<BR>Turn it off by all means. And please make sure that =
it's=20
really turned off, not only invisible (i.e. console is not a=20
=
target).<BR><BR>Cheers<BR>/Eike<BR><BR><BR></BLOCKQUOTE ></BLOCKQUOTE></BL=
OCKQUOTE></BODY></HTML>

------=_NextPart_000_0540_01C8C234.B8DE3F40--
Re: [CDO] reading/writting throughput performances [message #124150 is a reply to message #124092] Fri, 30 May 2008 13:19 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Hi Martin,

and thanks for your quick answer ! what I did is the following :

I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and added
that :

Bundle-ClassPath: lib/hibernate3.jar,
lib/cglib-2.1.3.jar,
lib/commons-collections-2.1.1.jar,
lib/dom4j.jar,
lib/jta.jar
lib/asm-3.0.jar

and this directive :

Eclipse-BuddyPolicy: dependent

as stated in
http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries

Then I don't get the same error, now when I start my own plugin (JUnit
plugin test) depending on org.eclipse.emf.cdo.server.hibernate.libraries I
get :

java.lang.NoClassDefFoundError: org/objectweb/asm/Type
at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
at
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)

These jars are such a headache ! Do you know - by chance - what's going
on ?


Cédric


Martin Taal wrote:

> Hi Cédric,
> Most of the time this exception is thrown because hibernate can't find the
> class. A common cause is that the hibernate jar files are located in a
> separate plugin which can not reach the classes in other plugins. If you
> set the eclipse buddy policy of the hibernate plugin to dependent then
> this can help.
>
> gr. Martin
>
> Cédric Brun wrote:
>> Hi Simon and Eike,
>>
>> thanks for your feedback, now I know what I could expect in using
>> optimized implementation, I'll have a try on the hibernate store and see
>> if it is scaling in a better way.
>>
>> You gave me many pointers to explain the performances issues but in fact
>> it seems that the SQL execution is taking so much time (not suprisingly
>> in fact ;) . My first profile was wrong.
>>
>> So I'm installing the hibernate store retrieving all the source code from
>> CVS, and I'm trying to launch the unit tests. I added many jars and
>> everything gets compiled but most of the tests are failling with "
>>
>> "
>> org.hibernate.MappingException: Could not determine type for:
>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>> at table: cdo_features, for columns: [org.hibernate.mapping.Column(type)]
>> "
>>
>> any hint ?
>>
>> Cédric
>>
>>
>> Simon McDuff wrote:
>>
>>> We noticed a performance degradation in the following case:
>>>
>>> When we fetch a collection of objects that contains collections that we
>>> don't want to use. Ex:
>>>
>>> Model:
>>>
>>> ClassB
>>> {
>>> int foo1;
>>> List childrens1;
>>> List childrens2;
>>> List childrens3;
>>> };
>>>
>>> Code:
>>>
>>> Resource.contents contains objects of type ClassB.
>>>
>>> By fetching instances of classB, we will also fetched some items in the
>>> list(childrens1, childrens2, childrens3) The problem we had.. is we do
>>> not know if we want to use it. SO better not to download them.
>>>
>>> So In our production(we used our own IStore), we never download any
>>> objects from collection. I'm working at the moment to put in place all
>>> feature we used in the current CDO. That one will be part of
>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>> referenceChunkSize == 0.
>>>
>>> It is true that we obtain good performance.
>>> Worst case :
>>> 1500 objects /sec (Real fetch from disk. Page that contains the objects,
>>> wasn't in the cache of the filesystem.)
>>>
>>> Best case
>>> 12 000 objects/Sec (Fetch objects that are already in the case of the
>>> filesystem)
>>>
>>> (These statistics always fetch objects from server to client. The cache
>>> client isn't used)
>>>
>>> We have another optimization one with SmartReadAhead but for now only
>>> work
>>> for UI client. (for now) This is something we will integrate as well in
>>> CDO. But for now we concentrate on the other things.
>>>
>>> I used an Object database. Based on my preliminary test without CDO.
>>> I compare
>>>
>>> Hibernate vs Objectivity/EMF :
>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>
>>> The worst.. you will get 30 to 240 objects/sec or
>>> the best... you will get 500 to 4000 objects/sec
>>>
>>> Based on your comments... you are getting the worst (with Derby)!! :-)
>>>
>>>
>>> Another comments about insertion.
>>>
>>> We found another problem when we insert data(DOn't know if it is still
>>> true). Resource.Contents is a unique list. Basically each time we insert
>>> one element, it needs to fetch all the collection to see if we already
>>> have this element. Basically.. it is time consuming. In our case we are
>>> not going through this stage to persist our objects... but the objects
>>> are not accessible through that list.
>>>
>>>
>>>
>>> If speed is an issue for you!! We (You included :-)) can optimize it.
>>> What I like is Eike did a really good job doing that framwork and
>>> optimizations are easy to add. Also you can change your back-end without
>>> affecting you client side. (Maybe going to an Object database!!) THis
>>> was one of the purpose of CDO!! :-)
>>>
>>>
>>> Simon
>>>
>>>
>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de news:
>>> 483E9332.6050800@sympedia.de... Hi Cédric,
>>>
>>> That sounds interesting!
>>> Comments inline...
>>>
>>>
>>> Cédric Brun schrieb:
>>> Hi Eike,
>>>
>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>> measuring read/write throughput when I use CDO (RC2).
>>>
>>> I'm using an embeded-derby database, two different metamodels (complex
>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>> Features)
>>>
>>> The test is a "quick and dirty" one so please do not take these figures
>>> too seriously, I would just like to have your input about the "order of
>>> magnitude" I should expect or settings affecting seriously these
>>> performances. I tried both JVM and TCP acceptor but the performances are
>>> quite similar though JVM is a bit faster.
>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>> You used localhost for TCP transport I guess?
>>>
>>>
>>>
>>> * First case : building a small model (10000 elements) with the simple
>>> MM, only adding instances in an empty database :
>>> commiting change on every add I get a 2 objects per second rate.
>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>> Seems to be consistent with the fact that only for commits there is
>>> remote traffic. And the backend transaction management is another
>>> overhead. So the impact of the number objects/commit starts with
>>> bigger transactions.
>>>
>>>
>>> browsing the just commited elements opening a new transaction and
>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>> just iterating thanks to Resource.getAllContents().
>>> Hehe, this is a sign that client side caching works well:
>>> All views and transactions of a single session share (and cache) their
>>> object state. Otherwise I'd expect much smaller values.
>>> With his ObjectivityStore implementation Simon (cc'ed) reached rates
>>> of several thousands objects/sec. But the DBStore (which you used) is
>>> not that optimized.
>>>
>>>
>>> * Second case : I built a big model in the database using the complex
>>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>>> (I did not measured it exactly as it was launched during a night, but it
>>> seems I got around 100 objects/sec rate in writting as I was writting
>>> every 700 objects.
>>> Sounds not too bad.
>>>
>>>
>>>
>>> Once the model is built the derby database is 222 MB (which - I heard -
>>> is not so big for derby).
>>> Hmm, I have no extensive experience with Derby.
>>> To be honest, I'm really no database expert (although I can write
>>> simple SQL statements).
>>>
>>>
>>> Retrieving the distant resource and calling eAllContents() on it, I get
>>> a 50 Objects/sec rate at best, which mean my eAllContents() call would
>>> take 4 hours !
>>> Currently I'm not sure what exactly eAllContents() does do (iteration
>>> order and so). There are several CDO features that can have a major
>>> impact on load rates!
>>>
>>> - Collections (xrefs and containment) can be loaded lazily. I don't
>>> mean the target objects, which are lazy by default anyway, but even
>>> the target IDs that are in the collections. We call that "reference
>>> chunking" (but search for a better name is ongoing).
>>>
>>> public interface CDOSession extends CDOProtocolSession,
>>> IContainer<CDOView>
>>> {
>>> public int getReferenceChunkSize();
>>>
>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>
>>>
>>> - Loading collection elements (target objects) can be batched (the
>>> current name is even worse)
>>>
>>> public interface CDOView extends CDOProtocolView, INotifier
>>> {
>>> public int getLoadRevisionCollectionChunkSize();
>>>
>>> public void setLoadRevisionCollectionChunkSize(int
>>> loadRevisionCollectionChunkSize);
>>>
>>>
>>> - One of the most sophisticated feature is automatic model usage
>>> analyzation. The result are fetch rules that are sent to the server.
>>> When later objects are loaded from the server, it can answer with
>>> additional objects that are likely to be needed by the client in the
>>> near future.
>>>
>>> public class CDOViewImpl extends
>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>> CDOView, CDOIDProvider, Adapter.Internal
>>> {
>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>> {
>>> return featureAnalyzer;
>>> }
>>>
>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>> featureAnalyzer)
>>> {
>>> this.featureAnalyzer = featureAnalyzer == null ?
>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>> }
>>>
>>>
>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>> Simon). - Caches can be configured
>>> - ...
>>>
>>>
>>> Known issues of the DBStore:
>>> - When in auditing mode updates are always written as complete inserts
>>> (by design) - When configuring toManyReferences to a value different
>>> from LIKE_ATTRIBUTES (which is not implemented yet) it is very slow. -
>>> No (few) prepared statements are used (see
>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>> others...
>>>
>>> Please note that the DBStore was not written by me to compete with
>>> Hibernate in terms of performance or mapping capabilities. Now that
>>> Martin and I, well in the end mostly Martin, provide a HibernateStore
>>> and this HibernateStore gets more and more features I expect that
>>> there will be a trend away from the DBStore.
>>>
>>>
>>> This is probably linked to the way the mapping to db is done, here's the
>>> config I used (came from CDO-server example if I recall correctly).
>>>
>>>
>>> <repository name="repo1">
>>> <property name="overrideUUID"
>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>> <property name="supportingAudits" value="true"/>
>>> <property name="verifyingRevisions" value="false"/>
>>> <property name="currentLRUCapacity" value="10000"/>
>>> I guess this one could be larger.
>>>
>>>
>>> <property name="revisedLRUCapacity" value="100"/>
>>>
>>> <store type="db">
>>> <!-- type: horizontal | vertical | <any
>>> user-contributed type> --> <mappingStrategy
>>> type="horizontal">
>>> <!-- ONE_TABLE_PER_REFERENCE |
>>> ONE_TABLE_PER_CLASS |
>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>> <property name="toManyReferences"
>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>
>>> <!-- LIKE_ATTRIBUTES |
>>> LIKE_TO_MANY_REFERENCES --> <property
>>> name="toOneReferences"
>>> value="LIKE_ATTRIBUTES"/>
>>>
>>> <!-- MODEL | STRATEGY -->
>>> <property name="mappingPrecedence"
>>> value="MODEL"/>
>>> This one is obsolete.
>>>
>>>
>>> </mappingStrategy>
>>>
>>> <dbAdapter name="derby-embedded"/>
>>> <dataSource
>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>> databaseName="/tmp/cdodb1"
>>> createDatabase="create"/>
>>>
>>> </store>
>>> </repository>
>>>
>>>
>>>
>>>
>>> What do you think about that ? What throughput do you think I should
>>> expect ? As I said that's very difficult to judge.
>>> I believe it's more appropriate to compare the actual values with
>>> values from other measures (other setups, properties, etc. or even
>>> other products) instead of random expectations. Apologies that I
>>> didn't have the time so far to provide some reference measures myself.
>>> Maybe this gets better now that the team starts to grow slowly ;-)
>>>
>>>
>>> What are the main reasons fur such figures ?
>>> Hmm, I *suspect* you don't like the figures? I can find no evidence
>>> your assessment ;-)
>>>
>>> Ahh,one more note:
>>> Tracing can also have a significant impact on performance and
>>> end-to-end throughput. Turn it off by all means. And please make sure
>>> that it's really turned off, not only invisible (i.e. console is not a
>>> target).
>>>
>>> Cheers
>>> /Eike
>>
>
>


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #124164 is a reply to message #124150] Fri, 30 May 2008 13:21 Go to previous messageGo to next message
Martin Taal is currently offline Martin TaalFriend
Messages: 5468
Registered: July 2009
Senior Member
Hmm, I can understand your headache. Classpath issues are the most annoying errors...

In your junit test source file, what happens when you enter the org.objectweb.asm.Type, can you
source file see this class?
Do you have cglib in some other plugin which does not have asm?

What I also find slightly strange is that cglib is used in this case because normally cdo objects
are not proxied using cglib. Can you post the generated mapping?
How does your cdo initialization code look like?

gr. Martin

Cédric Brun wrote:
> Hi Martin,
>
> and thanks for your quick answer ! what I did is the following :
>
> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and added
> that :
>
> Bundle-ClassPath: lib/hibernate3.jar,
> lib/cglib-2.1.3.jar,
> lib/commons-collections-2.1.1.jar,
> lib/dom4j.jar,
> lib/jta.jar
> lib/asm-3.0.jar
>
> and this directive :
>
> Eclipse-BuddyPolicy: dependent
>
> as stated in
> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>
> Then I don't get the same error, now when I start my own plugin (JUnit
> plugin test) depending on org.eclipse.emf.cdo.server.hibernate.libraries I
> get :
>
> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
> at
> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>
> These jars are such a headache ! Do you know - by chance - what's going
> on ?
>
>
> Cédric
>
>
> Martin Taal wrote:
>
>> Hi Cédric,
>> Most of the time this exception is thrown because hibernate can't find the
>> class. A common cause is that the hibernate jar files are located in a
>> separate plugin which can not reach the classes in other plugins. If you
>> set the eclipse buddy policy of the hibernate plugin to dependent then
>> this can help.
>>
>> gr. Martin
>>
>> Cédric Brun wrote:
>>> Hi Simon and Eike,
>>>
>>> thanks for your feedback, now I know what I could expect in using
>>> optimized implementation, I'll have a try on the hibernate store and see
>>> if it is scaling in a better way.
>>>
>>> You gave me many pointers to explain the performances issues but in fact
>>> it seems that the SQL execution is taking so much time (not suprisingly
>>> in fact ;) . My first profile was wrong.
>>>
>>> So I'm installing the hibernate store retrieving all the source code from
>>> CVS, and I'm trying to launch the unit tests. I added many jars and
>>> everything gets compiled but most of the tests are failling with "
>>>
>>> "
>>> org.hibernate.MappingException: Could not determine type for:
>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>> at table: cdo_features, for columns: [org.hibernate.mapping.Column(type)]
>>> "
>>>
>>> any hint ?
>>>
>>> Cédric
>>>
>>>
>>> Simon McDuff wrote:
>>>
>>>> We noticed a performance degradation in the following case:
>>>>
>>>> When we fetch a collection of objects that contains collections that we
>>>> don't want to use. Ex:
>>>>
>>>> Model:
>>>>
>>>> ClassB
>>>> {
>>>> int foo1;
>>>> List childrens1;
>>>> List childrens2;
>>>> List childrens3;
>>>> };
>>>>
>>>> Code:
>>>>
>>>> Resource.contents contains objects of type ClassB.
>>>>
>>>> By fetching instances of classB, we will also fetched some items in the
>>>> list(childrens1, childrens2, childrens3) The problem we had.. is we do
>>>> not know if we want to use it. SO better not to download them.
>>>>
>>>> So In our production(we used our own IStore), we never download any
>>>> objects from collection. I'm working at the moment to put in place all
>>>> feature we used in the current CDO. That one will be part of
>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>> referenceChunkSize == 0.
>>>>
>>>> It is true that we obtain good performance.
>>>> Worst case :
>>>> 1500 objects /sec (Real fetch from disk. Page that contains the objects,
>>>> wasn't in the cache of the filesystem.)
>>>>
>>>> Best case
>>>> 12 000 objects/Sec (Fetch objects that are already in the case of the
>>>> filesystem)
>>>>
>>>> (These statistics always fetch objects from server to client. The cache
>>>> client isn't used)
>>>>
>>>> We have another optimization one with SmartReadAhead but for now only
>>>> work
>>>> for UI client. (for now) This is something we will integrate as well in
>>>> CDO. But for now we concentrate on the other things.
>>>>
>>>> I used an Object database. Based on my preliminary test without CDO.
>>>> I compare
>>>>
>>>> Hibernate vs Objectivity/EMF :
>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>
>>>> The worst.. you will get 30 to 240 objects/sec or
>>>> the best... you will get 500 to 4000 objects/sec
>>>>
>>>> Based on your comments... you are getting the worst (with Derby)!! :-)
>>>>
>>>>
>>>> Another comments about insertion.
>>>>
>>>> We found another problem when we insert data(DOn't know if it is still
>>>> true). Resource.Contents is a unique list. Basically each time we insert
>>>> one element, it needs to fetch all the collection to see if we already
>>>> have this element. Basically.. it is time consuming. In our case we are
>>>> not going through this stage to persist our objects... but the objects
>>>> are not accessible through that list.
>>>>
>>>>
>>>>
>>>> If speed is an issue for you!! We (You included :-)) can optimize it.
>>>> What I like is Eike did a really good job doing that framwork and
>>>> optimizations are easy to add. Also you can change your back-end without
>>>> affecting you client side. (Maybe going to an Object database!!) THis
>>>> was one of the purpose of CDO!! :-)
>>>>
>>>>
>>>> Simon
>>>>
>>>>
>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de news:
>>>> 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>
>>>> That sounds interesting!
>>>> Comments inline...
>>>>
>>>>
>>>> Cédric Brun schrieb:
>>>> Hi Eike,
>>>>
>>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>>> measuring read/write throughput when I use CDO (RC2).
>>>>
>>>> I'm using an embeded-derby database, two different metamodels (complex
>>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>>> Features)
>>>>
>>>> The test is a "quick and dirty" one so please do not take these figures
>>>> too seriously, I would just like to have your input about the "order of
>>>> magnitude" I should expect or settings affecting seriously these
>>>> performances. I tried both JVM and TCP acceptor but the performances are
>>>> quite similar though JVM is a bit faster.
>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>> You used localhost for TCP transport I guess?
>>>>
>>>>
>>>>
>>>> * First case : building a small model (10000 elements) with the simple
>>>> MM, only adding instances in an empty database :
>>>> commiting change on every add I get a 2 objects per second rate.
>>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>> Seems to be consistent with the fact that only for commits there is
>>>> remote traffic. And the backend transaction management is another
>>>> overhead. So the impact of the number objects/commit starts with
>>>> bigger transactions.
>>>>
>>>>
>>>> browsing the just commited elements opening a new transaction and
>>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>>> just iterating thanks to Resource.getAllContents().
>>>> Hehe, this is a sign that client side caching works well:
>>>> All views and transactions of a single session share (and cache) their
>>>> object state. Otherwise I'd expect much smaller values.
>>>> With his ObjectivityStore implementation Simon (cc'ed) reached rates
>>>> of several thousands objects/sec. But the DBStore (which you used) is
>>>> not that optimized.
>>>>
>>>>
>>>> * Second case : I built a big model in the database using the complex
>>>> metamodel. It contains 700 000 elements. The creation went pretty nicely
>>>> (I did not measured it exactly as it was launched during a night, but it
>>>> seems I got around 100 objects/sec rate in writting as I was writting
>>>> every 700 objects.
>>>> Sounds not too bad.
>>>>
>>>>
>>>>
>>>> Once the model is built the derby database is 222 MB (which - I heard -
>>>> is not so big for derby).
>>>> Hmm, I have no extensive experience with Derby.
>>>> To be honest, I'm really no database expert (although I can write
>>>> simple SQL statements).
>>>>
>>>>
>>>> Retrieving the distant resource and calling eAllContents() on it, I get
>>>> a 50 Objects/sec rate at best, which mean my eAllContents() call would
>>>> take 4 hours !
>>>> Currently I'm not sure what exactly eAllContents() does do (iteration
>>>> order and so). There are several CDO features that can have a major
>>>> impact on load rates!
>>>>
>>>> - Collections (xrefs and containment) can be loaded lazily. I don't
>>>> mean the target objects, which are lazy by default anyway, but even
>>>> the target IDs that are in the collections. We call that "reference
>>>> chunking" (but search for a better name is ongoing).
>>>>
>>>> public interface CDOSession extends CDOProtocolSession,
>>>> IContainer<CDOView>
>>>> {
>>>> public int getReferenceChunkSize();
>>>>
>>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>>
>>>>
>>>> - Loading collection elements (target objects) can be batched (the
>>>> current name is even worse)
>>>>
>>>> public interface CDOView extends CDOProtocolView, INotifier
>>>> {
>>>> public int getLoadRevisionCollectionChunkSize();
>>>>
>>>> public void setLoadRevisionCollectionChunkSize(int
>>>> loadRevisionCollectionChunkSize);
>>>>
>>>>
>>>> - One of the most sophisticated feature is automatic model usage
>>>> analyzation. The result are fetch rules that are sent to the server.
>>>> When later objects are loaded from the server, it can answer with
>>>> additional objects that are likely to be needed by the client in the
>>>> near future.
>>>>
>>>> public class CDOViewImpl extends
>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>> {
>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>> {
>>>> return featureAnalyzer;
>>>> }
>>>>
>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>> featureAnalyzer)
>>>> {
>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>> }
>>>>
>>>>
>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>> Simon). - Caches can be configured
>>>> - ...
>>>>
>>>>
>>>> Known issues of the DBStore:
>>>> - When in auditing mode updates are always written as complete inserts
>>>> (by design) - When configuring toManyReferences to a value different
>>>> from LIKE_ATTRIBUTES (which is not implemented yet) it is very slow. -
>>>> No (few) prepared statements are used (see
>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>> others...
>>>>
>>>> Please note that the DBStore was not written by me to compete with
>>>> Hibernate in terms of performance or mapping capabilities. Now that
>>>> Martin and I, well in the end mostly Martin, provide a HibernateStore
>>>> and this HibernateStore gets more and more features I expect that
>>>> there will be a trend away from the DBStore.
>>>>
>>>>
>>>> This is probably linked to the way the mapping to db is done, here's the
>>>> config I used (came from CDO-server example if I recall correctly).
>>>>
>>>>
>>>> <repository name="repo1">
>>>> <property name="overrideUUID"
>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>> <property name="supportingAudits" value="true"/>
>>>> <property name="verifyingRevisions" value="false"/>
>>>> <property name="currentLRUCapacity" value="10000"/>
>>>> I guess this one could be larger.
>>>>
>>>>
>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>
>>>> <store type="db">
>>>> <!-- type: horizontal | vertical | <any
>>>> user-contributed type> --> <mappingStrategy
>>>> type="horizontal">
>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>> ONE_TABLE_PER_CLASS |
>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>>> <property name="toManyReferences"
>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>
>>>> <!-- LIKE_ATTRIBUTES |
>>>> LIKE_TO_MANY_REFERENCES --> <property
>>>> name="toOneReferences"
>>>> value="LIKE_ATTRIBUTES"/>
>>>>
>>>> <!-- MODEL | STRATEGY -->
>>>> <property name="mappingPrecedence"
>>>> value="MODEL"/>
>>>> This one is obsolete.
>>>>
>>>>
>>>> </mappingStrategy>
>>>>
>>>> <dbAdapter name="derby-embedded"/>
>>>> <dataSource
>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>> databaseName="/tmp/cdodb1"
>>>> createDatabase="create"/>
>>>>
>>>> </store>
>>>> </repository>
>>>>
>>>>
>>>>
>>>>
>>>> What do you think about that ? What throughput do you think I should
>>>> expect ? As I said that's very difficult to judge.
>>>> I believe it's more appropriate to compare the actual values with
>>>> values from other measures (other setups, properties, etc. or even
>>>> other products) instead of random expectations. Apologies that I
>>>> didn't have the time so far to provide some reference measures myself.
>>>> Maybe this gets better now that the team starts to grow slowly ;-)
>>>>
>>>>
>>>> What are the main reasons fur such figures ?
>>>> Hmm, I *suspect* you don't like the figures? I can find no evidence
>>>> your assessment ;-)
>>>>
>>>> Ahh,one more note:
>>>> Tracing can also have a significant impact on performance and
>>>> end-to-end throughput. Turn it off by all means. And please make sure
>>>> that it's really turned off, not only invisible (i.e. console is not a
>>>> target).
>>>>
>>>> Cheers
>>>> /Eike
>>
>


--

With Regards, Martin Taal

Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
Re: [CDO] reading/writting throughput performances [message #124231 is a reply to message #124164] Fri, 30 May 2008 14:34 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
I tried to do the same things as in the CDO/Hibernate unit tests.

Here's a zipped project trying to launch an HibernateServer with a unit test
adding elements.
( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip) The
libs I found are included in the same project, but I still have no luck and
failling at :

at
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
... 62 more
Caused by: java.lang.NoClassDefFoundError:
org/hibernate/proxy/HibernateProxy
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
... 68 more

please note that the test project I provide really is a "quick and ugly" one
^^


Cédric



Martin Taal wrote:

> Hmm, I can understand your headache. Classpath issues are the most
> annoying errors...
>
> In your junit test source file, what happens when you enter the
> org.objectweb.asm.Type, can you source file see this class?
> Do you have cglib in some other plugin which does not have asm?
>
> What I also find slightly strange is that cglib is used in this case
> because normally cdo objects are not proxied using cglib. Can you post the
> generated mapping? How does your cdo initialization code look like?
>
> gr. Martin
>
> Cédric Brun wrote:
>> Hi Martin,
>>
>> and thanks for your quick answer ! what I did is the following :
>>
>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and
>> added that :
>>
>> Bundle-ClassPath: lib/hibernate3.jar,
>> lib/cglib-2.1.3.jar,
>> lib/commons-collections-2.1.1.jar,
>> lib/dom4j.jar,
>> lib/jta.jar
>> lib/asm-3.0.jar
>>
>> and this directive :
>>
>> Eclipse-BuddyPolicy: dependent
>>
>> as stated in
>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>
>> Then I don't get the same error, now when I start my own plugin (JUnit
>> plugin test) depending on org.eclipse.emf.cdo.server.hibernate.libraries
>> I get :
>>
>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>> at
>>
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>
>> These jars are such a headache ! Do you know - by chance - what's going
>> on ?
>>
>>
>> Cédric
>>
>>
>> Martin Taal wrote:
>>
>>> Hi Cédric,
>>> Most of the time this exception is thrown because hibernate can't find
>>> the class. A common cause is that the hibernate jar files are located in
>>> a separate plugin which can not reach the classes in other plugins. If
>>> you set the eclipse buddy policy of the hibernate plugin to dependent
>>> then this can help.
>>>
>>> gr. Martin
>>>
>>> Cédric Brun wrote:
>>>> Hi Simon and Eike,
>>>>
>>>> thanks for your feedback, now I know what I could expect in using
>>>> optimized implementation, I'll have a try on the hibernate store and
>>>> see if it is scaling in a better way.
>>>>
>>>> You gave me many pointers to explain the performances issues but in
>>>> fact it seems that the SQL execution is taking so much time (not
>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>
>>>> So I'm installing the hibernate store retrieving all the source code
>>>> from CVS, and I'm trying to launch the unit tests. I added many jars
>>>> and everything gets compiled but most of the tests are failling with "
>>>>
>>>> "
>>>> org.hibernate.MappingException: Could not determine type for:
>>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>> at table: cdo_features, for columns:
>>>> [org.hibernate.mapping.Column(type)] "
>>>>
>>>> any hint ?
>>>>
>>>> Cédric
>>>>
>>>>
>>>> Simon McDuff wrote:
>>>>
>>>>> We noticed a performance degradation in the following case:
>>>>>
>>>>> When we fetch a collection of objects that contains collections that
>>>>> we don't want to use. Ex:
>>>>>
>>>>> Model:
>>>>>
>>>>> ClassB
>>>>> {
>>>>> int foo1;
>>>>> List childrens1;
>>>>> List childrens2;
>>>>> List childrens3;
>>>>> };
>>>>>
>>>>> Code:
>>>>>
>>>>> Resource.contents contains objects of type ClassB.
>>>>>
>>>>> By fetching instances of classB, we will also fetched some items in
>>>>> the list(childrens1, childrens2, childrens3) The problem we had.. is
>>>>> we do not know if we want to use it. SO better not to download them.
>>>>>
>>>>> So In our production(we used our own IStore), we never download any
>>>>> objects from collection. I'm working at the moment to put in place all
>>>>> feature we used in the current CDO. That one will be part of
>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>> referenceChunkSize == 0.
>>>>>
>>>>> It is true that we obtain good performance.
>>>>> Worst case :
>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>
>>>>> Best case
>>>>> 12 000 objects/Sec (Fetch objects that are already in the case of the
>>>>> filesystem)
>>>>>
>>>>> (These statistics always fetch objects from server to client. The
>>>>> cache client isn't used)
>>>>>
>>>>> We have another optimization one with SmartReadAhead but for now only
>>>>> work
>>>>> for UI client. (for now) This is something we will integrate as well
>>>>> in CDO. But for now we concentrate on the other things.
>>>>>
>>>>> I used an Object database. Based on my preliminary test without CDO.
>>>>> I compare
>>>>>
>>>>> Hibernate vs Objectivity/EMF :
>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>
>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>
>>>>> Based on your comments... you are getting the worst (with Derby)!! :-)
>>>>>
>>>>>
>>>>> Another comments about insertion.
>>>>>
>>>>> We found another problem when we insert data(DOn't know if it is still
>>>>> true). Resource.Contents is a unique list. Basically each time we
>>>>> insert one element, it needs to fetch all the collection to see if we
>>>>> already have this element. Basically.. it is time consuming. In our
>>>>> case we are not going through this stage to persist our objects... but
>>>>> the objects are not accessible through that list.
>>>>>
>>>>>
>>>>>
>>>>> If speed is an issue for you!! We (You included :-)) can optimize it.
>>>>> What I like is Eike did a really good job doing that framwork and
>>>>> optimizations are easy to add. Also you can change your back-end
>>>>> without affecting you client side. (Maybe going to an Object
>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>
>>>>>
>>>>> Simon
>>>>>
>>>>>
>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de
>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>
>>>>> That sounds interesting!
>>>>> Comments inline...
>>>>>
>>>>>
>>>>> Cédric Brun schrieb:
>>>>> Hi Eike,
>>>>>
>>>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>>>> measuring read/write throughput when I use CDO (RC2).
>>>>>
>>>>> I'm using an embeded-derby database, two different metamodels (complex
>>>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>>>> Features)
>>>>>
>>>>> The test is a "quick and dirty" one so please do not take these
>>>>> figures too seriously, I would just like to have your input about the
>>>>> "order of magnitude" I should expect or settings affecting seriously
>>>>> these performances. I tried both JVM and TCP acceptor but the
>>>>> performances are quite similar though JVM is a bit faster.
>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>> You used localhost for TCP transport I guess?
>>>>>
>>>>>
>>>>>
>>>>> * First case : building a small model (10000 elements) with the simple
>>>>> MM, only adding instances in an empty database :
>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>>> Seems to be consistent with the fact that only for commits there is
>>>>> remote traffic. And the backend transaction management is another
>>>>> overhead. So the impact of the number objects/commit starts with
>>>>> bigger transactions.
>>>>>
>>>>>
>>>>> browsing the just commited elements opening a new transaction and
>>>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>>>> just iterating thanks to Resource.getAllContents().
>>>>> Hehe, this is a sign that client side caching works well:
>>>>> All views and transactions of a single session share (and cache)
>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached rates
>>>>> of several thousands objects/sec. But the DBStore (which you used)
>>>>> is not that optimized.
>>>>>
>>>>>
>>>>> * Second case : I built a big model in the database using the complex
>>>>> metamodel. It contains 700 000 elements. The creation went pretty
>>>>> nicely (I did not measured it exactly as it was launched during a
>>>>> night, but it seems I got around 100 objects/sec rate in writting as I
>>>>> was writting every 700 objects.
>>>>> Sounds not too bad.
>>>>>
>>>>>
>>>>>
>>>>> Once the model is built the derby database is 222 MB (which - I heard
>>>>> - is not so big for derby).
>>>>> Hmm, I have no extensive experience with Derby.
>>>>> To be honest, I'm really no database expert (although I can write
>>>>> simple SQL statements).
>>>>>
>>>>>
>>>>> Retrieving the distant resource and calling eAllContents() on it, I
>>>>> get a 50 Objects/sec rate at best, which mean my eAllContents() call
>>>>> would take 4 hours !
>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>> (iteration order and so). There are several CDO features that can
>>>>> have a major impact on load rates!
>>>>>
>>>>> - Collections (xrefs and containment) can be loaded lazily. I don't
>>>>> mean the target objects, which are lazy by default anyway, but even
>>>>> the target IDs that are in the collections. We call that "reference
>>>>> chunking" (but search for a better name is ongoing).
>>>>>
>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>> IContainer<CDOView>
>>>>> {
>>>>> public int getReferenceChunkSize();
>>>>>
>>>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>>>
>>>>>
>>>>> - Loading collection elements (target objects) can be batched (the
>>>>> current name is even worse)
>>>>>
>>>>> public interface CDOView extends CDOProtocolView, INotifier
>>>>> {
>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>
>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>> loadRevisionCollectionChunkSize);
>>>>>
>>>>>
>>>>> - One of the most sophisticated feature is automatic model usage
>>>>> analyzation. The result are fetch rules that are sent to the server.
>>>>> When later objects are loaded from the server, it can answer with
>>>>> additional objects that are likely to be needed by the client in the
>>>>> near future.
>>>>>
>>>>> public class CDOViewImpl extends
>>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>> {
>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>> {
>>>>> return featureAnalyzer;
>>>>> }
>>>>>
>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>> featureAnalyzer)
>>>>> {
>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>> }
>>>>>
>>>>>
>>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>>> Simon). - Caches can be configured
>>>>> - ...
>>>>>
>>>>>
>>>>> Known issues of the DBStore:
>>>>> - When in auditing mode updates are always written as complete
>>>>> inserts (by design) - When configuring toManyReferences to a value
>>>>> different from LIKE_ATTRIBUTES (which is not implemented yet) it is
>>>>> very slow. - No (few) prepared statements are used (see
>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>> others...
>>>>>
>>>>> Please note that the DBStore was not written by me to compete with
>>>>> Hibernate in terms of performance or mapping capabilities. Now that
>>>>> Martin and I, well in the end mostly Martin, provide a
>>>>> HibernateStore and this HibernateStore gets more and more features I
>>>>> expect that there will be a trend away from the DBStore.
>>>>>
>>>>>
>>>>> This is probably linked to the way the mapping to db is done, here's
>>>>> the config I used (came from CDO-server example if I recall
>>>>> correctly).
>>>>>
>>>>>
>>>>> <repository name="repo1">
>>>>> <property name="overrideUUID"
>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>> <property name="supportingAudits" value="true"/>
>>>>> <property name="verifyingRevisions" value="false"/>
>>>>> <property name="currentLRUCapacity" value="10000"/>
>>>>> I guess this one could be larger.
>>>>>
>>>>>
>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>
>>>>> <store type="db">
>>>>> <!-- type: horizontal | vertical | <any
>>>>> user-contributed type> --> <mappingStrategy
>>>>> type="horizontal">
>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>> ONE_TABLE_PER_CLASS |
>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>>>> <property name="toManyReferences"
>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>
>>>>> <!-- LIKE_ATTRIBUTES |
>>>>> LIKE_TO_MANY_REFERENCES --> <property
>>>>> name="toOneReferences"
>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>
>>>>> <!-- MODEL | STRATEGY -->
>>>>> <property name="mappingPrecedence"
>>>>> value="MODEL"/>
>>>>> This one is obsolete.
>>>>>
>>>>>
>>>>> </mappingStrategy>
>>>>>
>>>>> <dbAdapter name="derby-embedded"/>
>>>>> <dataSource
>>>>>
class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>> databaseName="/tmp/cdodb1"
>>>>> createDatabase="create"/>
>>>>>
>>>>> </store>
>>>>> </repository>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> What do you think about that ? What throughput do you think I should
>>>>> expect ? As I said that's very difficult to judge.
>>>>> I believe it's more appropriate to compare the actual values with
>>>>> values from other measures (other setups, properties, etc. or even
>>>>> other products) instead of random expectations. Apologies that I
>>>>> didn't have the time so far to provide some reference measures
>>>>> myself. Maybe this gets better now that the team starts to grow
>>>>> slowly ;-)
>>>>>
>>>>>
>>>>> What are the main reasons fur such figures ?
>>>>> Hmm, I *suspect* you don't like the figures? I can find no evidence
>>>>> your assessment ;-)
>>>>>
>>>>> Ahh,one more note:
>>>>> Tracing can also have a significant impact on performance and
>>>>> end-to-end throughput. Turn it off by all means. And please make
>>>>> sure that it's really turned off, not only invisible (i.e. console
>>>>> is not a target).
>>>>>
>>>>> Cheers
>>>>> /Eike
>>>
>>
>
>


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #124246 is a reply to message #124231] Fri, 30 May 2008 14:30 Go to previous messageGo to next message
Martin Taal is currently offline Martin TaalFriend
Messages: 5468
Registered: July 2009
Senior Member
I am downloading your zip-file. I don't have time to look at it right away but I will do my best
later this evening.

gr. Martin

Cédric Brun wrote:
> I tried to do the same things as in the CDO/Hibernate unit tests.
>
> Here's a zipped project trying to launch an HibernateServer with a unit test
> adding elements.
> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip) The
> libs I found are included in the same project, but I still have no luck and
> failling at :
>
> at
> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
> ... 62 more
> Caused by: java.lang.NoClassDefFoundError:
> org/hibernate/proxy/HibernateProxy
> at java.lang.ClassLoader.defineClass1(Native Method)
> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
> ... 68 more
>
> please note that the test project I provide really is a "quick and ugly" one
> ^^
>
>
> Cédric
>
>
>
> Martin Taal wrote:
>
>> Hmm, I can understand your headache. Classpath issues are the most
>> annoying errors...
>>
>> In your junit test source file, what happens when you enter the
>> org.objectweb.asm.Type, can you source file see this class?
>> Do you have cglib in some other plugin which does not have asm?
>>
>> What I also find slightly strange is that cglib is used in this case
>> because normally cdo objects are not proxied using cglib. Can you post the
>> generated mapping? How does your cdo initialization code look like?
>>
>> gr. Martin
>>
>> Cédric Brun wrote:
>>> Hi Martin,
>>>
>>> and thanks for your quick answer ! what I did is the following :
>>>
>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and
>>> added that :
>>>
>>> Bundle-ClassPath: lib/hibernate3.jar,
>>> lib/cglib-2.1.3.jar,
>>> lib/commons-collections-2.1.1.jar,
>>> lib/dom4j.jar,
>>> lib/jta.jar
>>> lib/asm-3.0.jar
>>>
>>> and this directive :
>>>
>>> Eclipse-BuddyPolicy: dependent
>>>
>>> as stated in
>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>
>>> Then I don't get the same error, now when I start my own plugin (JUnit
>>> plugin test) depending on org.eclipse.emf.cdo.server.hibernate.libraries
>>> I get :
>>>
>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>> at
>>>
> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>> These jars are such a headache ! Do you know - by chance - what's going
>>> on ?
>>>
>>>
>>> Cédric
>>>
>>>
>>> Martin Taal wrote:
>>>
>>>> Hi Cédric,
>>>> Most of the time this exception is thrown because hibernate can't find
>>>> the class. A common cause is that the hibernate jar files are located in
>>>> a separate plugin which can not reach the classes in other plugins. If
>>>> you set the eclipse buddy policy of the hibernate plugin to dependent
>>>> then this can help.
>>>>
>>>> gr. Martin
>>>>
>>>> Cédric Brun wrote:
>>>>> Hi Simon and Eike,
>>>>>
>>>>> thanks for your feedback, now I know what I could expect in using
>>>>> optimized implementation, I'll have a try on the hibernate store and
>>>>> see if it is scaling in a better way.
>>>>>
>>>>> You gave me many pointers to explain the performances issues but in
>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>
>>>>> So I'm installing the hibernate store retrieving all the source code
>>>>> from CVS, and I'm trying to launch the unit tests. I added many jars
>>>>> and everything gets compiled but most of the tests are failling with "
>>>>>
>>>>> "
>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>> at table: cdo_features, for columns:
>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>
>>>>> any hint ?
>>>>>
>>>>> Cédric
>>>>>
>>>>>
>>>>> Simon McDuff wrote:
>>>>>
>>>>>> We noticed a performance degradation in the following case:
>>>>>>
>>>>>> When we fetch a collection of objects that contains collections that
>>>>>> we don't want to use. Ex:
>>>>>>
>>>>>> Model:
>>>>>>
>>>>>> ClassB
>>>>>> {
>>>>>> int foo1;
>>>>>> List childrens1;
>>>>>> List childrens2;
>>>>>> List childrens3;
>>>>>> };
>>>>>>
>>>>>> Code:
>>>>>>
>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>
>>>>>> By fetching instances of classB, we will also fetched some items in
>>>>>> the list(childrens1, childrens2, childrens3) The problem we had.. is
>>>>>> we do not know if we want to use it. SO better not to download them.
>>>>>>
>>>>>> So In our production(we used our own IStore), we never download any
>>>>>> objects from collection. I'm working at the moment to put in place all
>>>>>> feature we used in the current CDO. That one will be part of
>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>> referenceChunkSize == 0.
>>>>>>
>>>>>> It is true that we obtain good performance.
>>>>>> Worst case :
>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>
>>>>>> Best case
>>>>>> 12 000 objects/Sec (Fetch objects that are already in the case of the
>>>>>> filesystem)
>>>>>>
>>>>>> (These statistics always fetch objects from server to client. The
>>>>>> cache client isn't used)
>>>>>>
>>>>>> We have another optimization one with SmartReadAhead but for now only
>>>>>> work
>>>>>> for UI client. (for now) This is something we will integrate as well
>>>>>> in CDO. But for now we concentrate on the other things.
>>>>>>
>>>>>> I used an Object database. Based on my preliminary test without CDO.
>>>>>> I compare
>>>>>>
>>>>>> Hibernate vs Objectivity/EMF :
>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>
>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>
>>>>>> Based on your comments... you are getting the worst (with Derby)!! :-)
>>>>>>
>>>>>>
>>>>>> Another comments about insertion.
>>>>>>
>>>>>> We found another problem when we insert data(DOn't know if it is still
>>>>>> true). Resource.Contents is a unique list. Basically each time we
>>>>>> insert one element, it needs to fetch all the collection to see if we
>>>>>> already have this element. Basically.. it is time consuming. In our
>>>>>> case we are not going through this stage to persist our objects... but
>>>>>> the objects are not accessible through that list.
>>>>>>
>>>>>>
>>>>>>
>>>>>> If speed is an issue for you!! We (You included :-)) can optimize it.
>>>>>> What I like is Eike did a really good job doing that framwork and
>>>>>> optimizations are easy to add. Also you can change your back-end
>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>
>>>>>>
>>>>>> Simon
>>>>>>
>>>>>>
>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de
>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>
>>>>>> That sounds interesting!
>>>>>> Comments inline...
>>>>>>
>>>>>>
>>>>>> Cédric Brun schrieb:
>>>>>> Hi Eike,
>>>>>>
>>>>>> I've been messing around CDO lately and I hacked a few ugly unit-tests
>>>>>> measuring read/write throughput when I use CDO (RC2).
>>>>>>
>>>>>> I'm using an embeded-derby database, two different metamodels (complex
>>>>>> one - 250 EClassifiers/300 features and a simple one - 1 Classifier/3
>>>>>> Features)
>>>>>>
>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>> figures too seriously, I would just like to have your input about the
>>>>>> "order of magnitude" I should expect or settings affecting seriously
>>>>>> these performances. I tried both JVM and TCP acceptor but the
>>>>>> performances are quite similar though JVM is a bit faster.
>>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>>> You used localhost for TCP transport I guess?
>>>>>>
>>>>>>
>>>>>>
>>>>>> * First case : building a small model (10000 elements) with the simple
>>>>>> MM, only adding instances in an empty database :
>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>> commiting changes every 10 adds - I get a 30 objects per second rate.
>>>>>> Seems to be consistent with the fact that only for commits there is
>>>>>> remote traffic. And the backend transaction management is another
>>>>>> overhead. So the impact of the number objects/commit starts with
>>>>>> bigger transactions.
>>>>>>
>>>>>>
>>>>>> browsing the just commited elements opening a new transaction and
>>>>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>> All views and transactions of a single session share (and cache)
>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached rates
>>>>>> of several thousands objects/sec. But the DBStore (which you used)
>>>>>> is not that optimized.
>>>>>>
>>>>>>
>>>>>> * Second case : I built a big model in the database using the complex
>>>>>> metamodel. It contains 700 000 elements. The creation went pretty
>>>>>> nicely (I did not measured it exactly as it was launched during a
>>>>>> night, but it seems I got around 100 objects/sec rate in writting as I
>>>>>> was writting every 700 objects.
>>>>>> Sounds not too bad.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Once the model is built the derby database is 222 MB (which - I heard
>>>>>> - is not so big for derby).
>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>> To be honest, I'm really no database expert (although I can write
>>>>>> simple SQL statements).
>>>>>>
>>>>>>
>>>>>> Retrieving the distant resource and calling eAllContents() on it, I
>>>>>> get a 50 Objects/sec rate at best, which mean my eAllContents() call
>>>>>> would take 4 hours !
>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>> (iteration order and so). There are several CDO features that can
>>>>>> have a major impact on load rates!
>>>>>>
>>>>>> - Collections (xrefs and containment) can be loaded lazily. I don't
>>>>>> mean the target objects, which are lazy by default anyway, but even
>>>>>> the target IDs that are in the collections. We call that "reference
>>>>>> chunking" (but search for a better name is ongoing).
>>>>>>
>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>> IContainer<CDOView>
>>>>>> {
>>>>>> public int getReferenceChunkSize();
>>>>>>
>>>>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>>>>
>>>>>>
>>>>>> - Loading collection elements (target objects) can be batched (the
>>>>>> current name is even worse)
>>>>>>
>>>>>> public interface CDOView extends CDOProtocolView, INotifier
>>>>>> {
>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>
>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>> loadRevisionCollectionChunkSize);
>>>>>>
>>>>>>
>>>>>> - One of the most sophisticated feature is automatic model usage
>>>>>> analyzation. The result are fetch rules that are sent to the server.
>>>>>> When later objects are loaded from the server, it can answer with
>>>>>> additional objects that are likely to be needed by the client in the
>>>>>> near future.
>>>>>>
>>>>>> public class CDOViewImpl extends
>>>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>> {
>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>> {
>>>>>> return featureAnalyzer;
>>>>>> }
>>>>>>
>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>> featureAnalyzer)
>>>>>> {
>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>> }
>>>>>>
>>>>>>
>>>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>>>> Simon). - Caches can be configured
>>>>>> - ...
>>>>>>
>>>>>>
>>>>>> Known issues of the DBStore:
>>>>>> - When in auditing mode updates are always written as complete
>>>>>> inserts (by design) - When configuring toManyReferences to a value
>>>>>> different from LIKE_ATTRIBUTES (which is not implemented yet) it is
>>>>>> very slow. - No (few) prepared statements are used (see
>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>> others...
>>>>>>
>>>>>> Please note that the DBStore was not written by me to compete with
>>>>>> Hibernate in terms of performance or mapping capabilities. Now that
>>>>>> Martin and I, well in the end mostly Martin, provide a
>>>>>> HibernateStore and this HibernateStore gets more and more features I
>>>>>> expect that there will be a trend away from the DBStore.
>>>>>>
>>>>>>
>>>>>> This is probably linked to the way the mapping to db is done, here's
>>>>>> the config I used (came from CDO-server example if I recall
>>>>>> correctly).
>>>>>>
>>>>>>
>>>>>> <repository name="repo1">
>>>>>> <property name="overrideUUID"
>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>> <property name="supportingAudits" value="true"/>
>>>>>> <property name="verifyingRevisions" value="false"/>
>>>>>> <property name="currentLRUCapacity" value="10000"/>
>>>>>> I guess this one could be larger.
>>>>>>
>>>>>>
>>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>>
>>>>>> <store type="db">
>>>>>> <!-- type: horizontal | vertical | <any
>>>>>> user-contributed type> --> <mappingStrategy
>>>>>> type="horizontal">
>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>> ONE_TABLE_PER_CLASS |
>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES -->
>>>>>> <property name="toManyReferences"
>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>
>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>> LIKE_TO_MANY_REFERENCES --> <property
>>>>>> name="toOneReferences"
>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>
>>>>>> <!-- MODEL | STRATEGY -->
>>>>>> <property name="mappingPrecedence"
>>>>>> value="MODEL"/>
>>>>>> This one is obsolete.
>>>>>>
>>>>>>
>>>>>> </mappingStrategy>
>>>>>>
>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>> <dataSource
>>>>>>
> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>> databaseName="/tmp/cdodb1"
>>>>>> createDatabase="create"/>
>>>>>>
>>>>>> </store>
>>>>>> </repository>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> What do you think about that ? What throughput do you think I should
>>>>>> expect ? As I said that's very difficult to judge.
>>>>>> I believe it's more appropriate to compare the actual values with
>>>>>> values from other measures (other setups, properties, etc. or even
>>>>>> other products) instead of random expectations. Apologies that I
>>>>>> didn't have the time so far to provide some reference measures
>>>>>> myself. Maybe this gets better now that the team starts to grow
>>>>>> slowly ;-)
>>>>>>
>>>>>>
>>>>>> What are the main reasons fur such figures ?
>>>>>> Hmm, I *suspect* you don't like the figures? I can find no evidence
>>>>>> your assessment ;-)
>>>>>>
>>>>>> Ahh,one more note:
>>>>>> Tracing can also have a significant impact on performance and
>>>>>> end-to-end throughput. Turn it off by all means. And please make
>>>>>> sure that it's really turned off, not only invisible (i.e. console
>>>>>> is not a target).
>>>>>>
>>>>>> Cheers
>>>>>> /Eike
>>
>


--

With Regards, Martin Taal

Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
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Re: [CDO] reading/writting throughput performances [message #124260 is a reply to message #124246] Fri, 30 May 2008 14:52 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Thanks a lot ! I'm looking forward to your advices !

Cédric

Martin Taal wrote:

> I am downloading your zip-file. I don't have time to look at it right away
> but I will do my best later this evening.
>
> gr. Martin
>
> Cédric Brun wrote:
>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>
>> Here's a zipped project trying to launch an HibernateServer with a unit
>> test adding elements.
>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip) The
>> libs I found are included in the same project, but I still have no luck
>> and failling at :
>>
>> at
>>
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>> ... 62 more
>> Caused by: java.lang.NoClassDefFoundError:
>> org/hibernate/proxy/HibernateProxy
>> at java.lang.ClassLoader.defineClass1(Native Method)
>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>> ... 68 more
>>
>> please note that the test project I provide really is a "quick and ugly"
>> one ^^
>>
>>
>> Cédric
>>
>>
>>
>> Martin Taal wrote:
>>
>>> Hmm, I can understand your headache. Classpath issues are the most
>>> annoying errors...
>>>
>>> In your junit test source file, what happens when you enter the
>>> org.objectweb.asm.Type, can you source file see this class?
>>> Do you have cglib in some other plugin which does not have asm?
>>>
>>> What I also find slightly strange is that cglib is used in this case
>>> because normally cdo objects are not proxied using cglib. Can you post
>>> the generated mapping? How does your cdo initialization code look like?
>>>
>>> gr. Martin
>>>
>>> Cédric Brun wrote:
>>>> Hi Martin,
>>>>
>>>> and thanks for your quick answer ! what I did is the following :
>>>>
>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and
>>>> added that :
>>>>
>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>> lib/cglib-2.1.3.jar,
>>>> lib/commons-collections-2.1.1.jar,
>>>> lib/dom4j.jar,
>>>> lib/jta.jar
>>>> lib/asm-3.0.jar
>>>>
>>>> and this directive :
>>>>
>>>> Eclipse-BuddyPolicy: dependent
>>>>
>>>> as stated in
>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>
>>>> Then I don't get the same error, now when I start my own plugin (JUnit
>>>> plugin test) depending on
>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>
>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>> at
>>>>
>>
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>> These jars are such a headache ! Do you know - by chance - what's
>>>> going on ?
>>>>
>>>>
>>>> Cédric
>>>>
>>>>
>>>> Martin Taal wrote:
>>>>
>>>>> Hi Cédric,
>>>>> Most of the time this exception is thrown because hibernate can't find
>>>>> the class. A common cause is that the hibernate jar files are located
>>>>> in a separate plugin which can not reach the classes in other plugins.
>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>> dependent then this can help.
>>>>>
>>>>> gr. Martin
>>>>>
>>>>> Cédric Brun wrote:
>>>>>> Hi Simon and Eike,
>>>>>>
>>>>>> thanks for your feedback, now I know what I could expect in using
>>>>>> optimized implementation, I'll have a try on the hibernate store and
>>>>>> see if it is scaling in a better way.
>>>>>>
>>>>>> You gave me many pointers to explain the performances issues but in
>>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>
>>>>>> So I'm installing the hibernate store retrieving all the source code
>>>>>> from CVS, and I'm trying to launch the unit tests. I added many jars
>>>>>> and everything gets compiled but most of the tests are failling with
>>>>>> "
>>>>>>
>>>>>> "
>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>> at table: cdo_features, for columns:
>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>
>>>>>> any hint ?
>>>>>>
>>>>>> Cédric
>>>>>>
>>>>>>
>>>>>> Simon McDuff wrote:
>>>>>>
>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>
>>>>>>> When we fetch a collection of objects that contains collections that
>>>>>>> we don't want to use. Ex:
>>>>>>>
>>>>>>> Model:
>>>>>>>
>>>>>>> ClassB
>>>>>>> {
>>>>>>> int foo1;
>>>>>>> List childrens1;
>>>>>>> List childrens2;
>>>>>>> List childrens3;
>>>>>>> };
>>>>>>>
>>>>>>> Code:
>>>>>>>
>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>
>>>>>>> By fetching instances of classB, we will also fetched some items in
>>>>>>> the list(childrens1, childrens2, childrens3) The problem we had.. is
>>>>>>> we do not know if we want to use it. SO better not to download them.
>>>>>>>
>>>>>>> So In our production(we used our own IStore), we never download any
>>>>>>> objects from collection. I'm working at the moment to put in place
>>>>>>> all feature we used in the current CDO. That one will be part of
>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>> referenceChunkSize == 0.
>>>>>>>
>>>>>>> It is true that we obtain good performance.
>>>>>>> Worst case :
>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>
>>>>>>> Best case
>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the case of
>>>>>>> the filesystem)
>>>>>>>
>>>>>>> (These statistics always fetch objects from server to client. The
>>>>>>> cache client isn't used)
>>>>>>>
>>>>>>> We have another optimization one with SmartReadAhead but for now
>>>>>>> only work
>>>>>>> for UI client. (for now) This is something we will integrate as
>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>
>>>>>>> I used an Object database. Based on my preliminary test without CDO.
>>>>>>> I compare
>>>>>>>
>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>
>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>
>>>>>>> Based on your comments... you are getting the worst (with Derby)!!
>>>>>>> :-)
>>>>>>>
>>>>>>>
>>>>>>> Another comments about insertion.
>>>>>>>
>>>>>>> We found another problem when we insert data(DOn't know if it is
>>>>>>> still true). Resource.Contents is a unique list. Basically each time
>>>>>>> we insert one element, it needs to fetch all the collection to see
>>>>>>> if we already have this element. Basically.. it is time consuming.
>>>>>>> In our case we are not going through this stage to persist our
>>>>>>> objects... but the objects are not accessible through that list.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> If speed is an issue for you!! We (You included :-)) can optimize
>>>>>>> it. What I like is Eike did a really good job doing that framwork
>>>>>>> and optimizations are easy to add. Also you can change your back-end
>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>
>>>>>>>
>>>>>>> Simon
>>>>>>>
>>>>>>>
>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de
>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>
>>>>>>> That sounds interesting!
>>>>>>> Comments inline...
>>>>>>>
>>>>>>>
>>>>>>> Cédric Brun schrieb:
>>>>>>> Hi Eike,
>>>>>>>
>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>> unit-tests measuring read/write throughput when I use CDO (RC2).
>>>>>>>
>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>> (complex one - 250 EClassifiers/300 features and a simple one - 1
>>>>>>> Classifier/3 Features)
>>>>>>>
>>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>>> figures too seriously, I would just like to have your input about
>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>> seriously these performances. I tried both JVM and TCP acceptor but
>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> * First case : building a small model (10000 elements) with the
>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>>> commiting changes every 10 adds - I get a 30 objects per second
>>>>>>> rate.
>>>>>>> Seems to be consistent with the fact that only for commits there
>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>> starts with bigger transactions.
>>>>>>>
>>>>>>>
>>>>>>> browsing the just commited elements opening a new transaction and
>>>>>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>> All views and transactions of a single session share (and cache)
>>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached
>>>>>>> rates of several thousands objects/sec. But the DBStore (which you
>>>>>>> used) is not that optimized.
>>>>>>>
>>>>>>>
>>>>>>> * Second case : I built a big model in the database using the
>>>>>>> complex metamodel. It contains 700 000 elements. The creation went
>>>>>>> pretty nicely (I did not measured it exactly as it was launched
>>>>>>> during a night, but it seems I got around 100 objects/sec rate in
>>>>>>> writting as I was writting every 700 objects.
>>>>>>> Sounds not too bad.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Once the model is built the derby database is 222 MB (which - I
>>>>>>> heard - is not so big for derby).
>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>> To be honest, I'm really no database expert (although I can write
>>>>>>> simple SQL statements).
>>>>>>>
>>>>>>>
>>>>>>> Retrieving the distant resource and calling eAllContents() on it, I
>>>>>>> get a 50 Objects/sec rate at best, which mean my eAllContents() call
>>>>>>> would take 4 hours !
>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>> (iteration order and so). There are several CDO features that can
>>>>>>> have a major impact on load rates!
>>>>>>>
>>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>>> don't mean the target objects, which are lazy by default anyway,
>>>>>>> but even the target IDs that are in the collections. We call that
>>>>>>> "reference chunking" (but search for a better name is ongoing).
>>>>>>>
>>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>>> IContainer<CDOView>
>>>>>>> {
>>>>>>> public int getReferenceChunkSize();
>>>>>>>
>>>>>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>>>>>
>>>>>>>
>>>>>>> - Loading collection elements (target objects) can be batched (the
>>>>>>> current name is even worse)
>>>>>>>
>>>>>>> public interface CDOView extends CDOProtocolView, INotifier
>>>>>>> {
>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>
>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>
>>>>>>>
>>>>>>> - One of the most sophisticated feature is automatic model usage
>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>> server. When later objects are loaded from the server, it can
>>>>>>> answer with additional objects that are likely to be needed by the
>>>>>>> client in the near future.
>>>>>>>
>>>>>>> public class CDOViewImpl extends
>>>>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>> {
>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>> {
>>>>>>> return featureAnalyzer;
>>>>>>> }
>>>>>>>
>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>> featureAnalyzer)
>>>>>>> {
>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>> }
>>>>>>>
>>>>>>>
>>>>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>>>>> Simon). - Caches can be configured
>>>>>>> - ...
>>>>>>>
>>>>>>>
>>>>>>> Known issues of the DBStore:
>>>>>>> - When in auditing mode updates are always written as complete
>>>>>>> inserts (by design) - When configuring toManyReferences to a value
>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented yet) it
>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>>> others...
>>>>>>>
>>>>>>> Please note that the DBStore was not written by me to compete with
>>>>>>> Hibernate in terms of performance or mapping capabilities. Now
>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>> HibernateStore and this HibernateStore gets more and more features
>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>
>>>>>>>
>>>>>>> This is probably linked to the way the mapping to db is done, here's
>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>> correctly).
>>>>>>>
>>>>>>>
>>>>>>> <repository name="repo1">
>>>>>>> <property name="overrideUUID"
>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>> <property name="supportingAudits" value="true"/>
>>>>>>> <property name="verifyingRevisions" value="false"/>
>>>>>>> <property name="currentLRUCapacity" value="10000"/>
>>>>>>> I guess this one could be larger.
>>>>>>>
>>>>>>>
>>>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>>>
>>>>>>> <store type="db">
>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>> user-contributed type> --> <mappingStrategy
>>>>>>> type="horizontal">
>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES
>>>>>>> -->
>>>>>>> <property name="toManyReferences"
>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>
>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>> <property name="toOneReferences"
>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>
>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>> <property name="mappingPrecedence"
>>>>>>> value="MODEL"/>
>>>>>>> This one is obsolete.
>>>>>>>
>>>>>>>
>>>>>>> </mappingStrategy>
>>>>>>>
>>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>>> <dataSource
>>>>>>>
>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>> createDatabase="create"/>
>>>>>>>
>>>>>>> </store>
>>>>>>> </repository>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> What do you think about that ? What throughput do you think I should
>>>>>>> expect ? As I said that's very difficult to judge.
>>>>>>> I believe it's more appropriate to compare the actual values with
>>>>>>> values from other measures (other setups, properties, etc. or even
>>>>>>> other products) instead of random expectations. Apologies that I
>>>>>>> didn't have the time so far to provide some reference measures
>>>>>>> myself. Maybe this gets better now that the team starts to grow
>>>>>>> slowly ;-)
>>>>>>>
>>>>>>>
>>>>>>> What are the main reasons fur such figures ?
>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>> evidence your assessment ;-)
>>>>>>>
>>>>>>> Ahh,one more note:
>>>>>>> Tracing can also have a significant impact on performance and
>>>>>>> end-to-end throughput. Turn it off by all means. And please make
>>>>>>> sure that it's really turned off, not only invisible (i.e. console
>>>>>>> is not a target).
>>>>>>>
>>>>>>> Cheers
>>>>>>> /Eike
>>>
>>
>
>


http://cedric.brun.io news and articles on eclipse and eclipse modeling.
Re: [CDO] reading/writting throughput performances [message #124481 is a reply to message #124260] Sat, 31 May 2008 23:02 Go to previous messageGo to next message
Martin Taal is currently offline Martin TaalFriend
Messages: 5468
Registered: July 2009
Senior Member
Hi Cédric,
I looked at it for many hours trying different things (using your testcase) but I am kind of stuck
with this (getting the same error as you). The difference I can see with the way I run the
cdo.hibernate testcases (as a junit test) and how your testcase is run (junit plugin test). This for
sure means difference in class loader behavior.

Eike, do you have an idea? I am not sure how classloading works when you start a cdo server in a
plugin. Which plugins are then available in the cdo server? The testcases can be downloaded from the
link below.

gr. Martin

Cédric Brun wrote:
> Thanks a lot ! I'm looking forward to your advices !
>
> Cédric
>
> Martin Taal wrote:
>
>> I am downloading your zip-file. I don't have time to look at it right away
>> but I will do my best later this evening.
>>
>> gr. Martin
>>
>> Cédric Brun wrote:
>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>
>>> Here's a zipped project trying to launch an HibernateServer with a unit
>>> test adding elements.
>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip) The
>>> libs I found are included in the same project, but I still have no luck
>>> and failling at :
>>>
>>> at
>>>
> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>> ... 62 more
>>> Caused by: java.lang.NoClassDefFoundError:
>>> org/hibernate/proxy/HibernateProxy
>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>> ... 68 more
>>>
>>> please note that the test project I provide really is a "quick and ugly"
>>> one ^^
>>>
>>>
>>> Cédric
>>>
>>>
>>>
>>> Martin Taal wrote:
>>>
>>>> Hmm, I can understand your headache. Classpath issues are the most
>>>> annoying errors...
>>>>
>>>> In your junit test source file, what happens when you enter the
>>>> org.objectweb.asm.Type, can you source file see this class?
>>>> Do you have cglib in some other plugin which does not have asm?
>>>>
>>>> What I also find slightly strange is that cglib is used in this case
>>>> because normally cdo objects are not proxied using cglib. Can you post
>>>> the generated mapping? How does your cdo initialization code look like?
>>>>
>>>> gr. Martin
>>>>
>>>> Cédric Brun wrote:
>>>>> Hi Martin,
>>>>>
>>>>> and thanks for your quick answer ! what I did is the following :
>>>>>
>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and
>>>>> added that :
>>>>>
>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>> lib/cglib-2.1.3.jar,
>>>>> lib/commons-collections-2.1.1.jar,
>>>>> lib/dom4j.jar,
>>>>> lib/jta.jar
>>>>> lib/asm-3.0.jar
>>>>>
>>>>> and this directive :
>>>>>
>>>>> Eclipse-BuddyPolicy: dependent
>>>>>
>>>>> as stated in
>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>
>>>>> Then I don't get the same error, now when I start my own plugin (JUnit
>>>>> plugin test) depending on
>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>
>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>> at
>>>>>
> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>>> These jars are such a headache ! Do you know - by chance - what's
>>>>> going on ?
>>>>>
>>>>>
>>>>> Cédric
>>>>>
>>>>>
>>>>> Martin Taal wrote:
>>>>>
>>>>>> Hi Cédric,
>>>>>> Most of the time this exception is thrown because hibernate can't find
>>>>>> the class. A common cause is that the hibernate jar files are located
>>>>>> in a separate plugin which can not reach the classes in other plugins.
>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>> dependent then this can help.
>>>>>>
>>>>>> gr. Martin
>>>>>>
>>>>>> Cédric Brun wrote:
>>>>>>> Hi Simon and Eike,
>>>>>>>
>>>>>>> thanks for your feedback, now I know what I could expect in using
>>>>>>> optimized implementation, I'll have a try on the hibernate store and
>>>>>>> see if it is scaling in a better way.
>>>>>>>
>>>>>>> You gave me many pointers to explain the performances issues but in
>>>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>
>>>>>>> So I'm installing the hibernate store retrieving all the source code
>>>>>>> from CVS, and I'm trying to launch the unit tests. I added many jars
>>>>>>> and everything gets compiled but most of the tests are failling with
>>>>>>> "
>>>>>>>
>>>>>>> "
>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>
> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>> at table: cdo_features, for columns:
>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>
>>>>>>> any hint ?
>>>>>>>
>>>>>>> Cédric
>>>>>>>
>>>>>>>
>>>>>>> Simon McDuff wrote:
>>>>>>>
>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>
>>>>>>>> When we fetch a collection of objects that contains collections that
>>>>>>>> we don't want to use. Ex:
>>>>>>>>
>>>>>>>> Model:
>>>>>>>>
>>>>>>>> ClassB
>>>>>>>> {
>>>>>>>> int foo1;
>>>>>>>> List childrens1;
>>>>>>>> List childrens2;
>>>>>>>> List childrens3;
>>>>>>>> };
>>>>>>>>
>>>>>>>> Code:
>>>>>>>>
>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>
>>>>>>>> By fetching instances of classB, we will also fetched some items in
>>>>>>>> the list(childrens1, childrens2, childrens3) The problem we had.. is
>>>>>>>> we do not know if we want to use it. SO better not to download them.
>>>>>>>>
>>>>>>>> So In our production(we used our own IStore), we never download any
>>>>>>>> objects from collection. I'm working at the moment to put in place
>>>>>>>> all feature we used in the current CDO. That one will be part of
>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>>> referenceChunkSize == 0.
>>>>>>>>
>>>>>>>> It is true that we obtain good performance.
>>>>>>>> Worst case :
>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>
>>>>>>>> Best case
>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the case of
>>>>>>>> the filesystem)
>>>>>>>>
>>>>>>>> (These statistics always fetch objects from server to client. The
>>>>>>>> cache client isn't used)
>>>>>>>>
>>>>>>>> We have another optimization one with SmartReadAhead but for now
>>>>>>>> only work
>>>>>>>> for UI client. (for now) This is something we will integrate as
>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>
>>>>>>>> I used an Object database. Based on my preliminary test without CDO.
>>>>>>>> I compare
>>>>>>>>
>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>>
>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>
>>>>>>>> Based on your comments... you are getting the worst (with Derby)!!
>>>>>>>> :-)
>>>>>>>>
>>>>>>>>
>>>>>>>> Another comments about insertion.
>>>>>>>>
>>>>>>>> We found another problem when we insert data(DOn't know if it is
>>>>>>>> still true). Resource.Contents is a unique list. Basically each time
>>>>>>>> we insert one element, it needs to fetch all the collection to see
>>>>>>>> if we already have this element. Basically.. it is time consuming.
>>>>>>>> In our case we are not going through this stage to persist our
>>>>>>>> objects... but the objects are not accessible through that list.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> If speed is an issue for you!! We (You included :-)) can optimize
>>>>>>>> it. What I like is Eike did a really good job doing that framwork
>>>>>>>> and optimizations are easy to add. Also you can change your back-end
>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>
>>>>>>>>
>>>>>>>> Simon
>>>>>>>>
>>>>>>>>
>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de
>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>
>>>>>>>> That sounds interesting!
>>>>>>>> Comments inline...
>>>>>>>>
>>>>>>>>
>>>>>>>> Cédric Brun schrieb:
>>>>>>>> Hi Eike,
>>>>>>>>
>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>> unit-tests measuring read/write throughput when I use CDO (RC2).
>>>>>>>>
>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple one - 1
>>>>>>>> Classifier/3 Features)
>>>>>>>>
>>>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>>>> figures too seriously, I would just like to have your input about
>>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>>> seriously these performances. I tried both JVM and TCP acceptor but
>>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>>> Looks like a sign that the NIO socket channels are efficient ,-)
>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> * First case : building a small model (10000 elements) with the
>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>>>> commiting changes every 10 adds - I get a 30 objects per second
>>>>>>>> rate.
>>>>>>>> Seems to be consistent with the fact that only for commits there
>>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>>> starts with bigger transactions.
>>>>>>>>
>>>>>>>>
>>>>>>>> browsing the just commited elements opening a new transaction and
>>>>>>>> getting a new Resource instance, I get around 30 000 objets/sec rate
>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>> All views and transactions of a single session share (and cache)
>>>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached
>>>>>>>> rates of several thousands objects/sec. But the DBStore (which you
>>>>>>>> used) is not that optimized.
>>>>>>>>
>>>>>>>>
>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>> complex metamodel. It contains 700 000 elements. The creation went
>>>>>>>> pretty nicely (I did not measured it exactly as it was launched
>>>>>>>> during a night, but it seems I got around 100 objects/sec rate in
>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>> Sounds not too bad.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Once the model is built the derby database is 222 MB (which - I
>>>>>>>> heard - is not so big for derby).
>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>> To be honest, I'm really no database expert (although I can write
>>>>>>>> simple SQL statements).
>>>>>>>>
>>>>>>>>
>>>>>>>> Retrieving the distant resource and calling eAllContents() on it, I
>>>>>>>> get a 50 Objects/sec rate at best, which mean my eAllContents() call
>>>>>>>> would take 4 hours !
>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>> (iteration order and so). There are several CDO features that can
>>>>>>>> have a major impact on load rates!
>>>>>>>>
>>>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>>>> don't mean the target objects, which are lazy by default anyway,
>>>>>>>> but even the target IDs that are in the collections. We call that
>>>>>>>> "reference chunking" (but search for a better name is ongoing).
>>>>>>>>
>>>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>>>> IContainer<CDOView>
>>>>>>>> {
>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>
>>>>>>>> public void setReferenceChunkSize(int referenceChunkSize);
>>>>>>>>
>>>>>>>>
>>>>>>>> - Loading collection elements (target objects) can be batched (the
>>>>>>>> current name is even worse)
>>>>>>>>
>>>>>>>> public interface CDOView extends CDOProtocolView, INotifier
>>>>>>>> {
>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>
>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>
>>>>>>>>
>>>>>>>> - One of the most sophisticated feature is automatic model usage
>>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>>> server. When later objects are loaded from the server, it can
>>>>>>>> answer with additional objects that are likely to be needed by the
>>>>>>>> client in the near future.
>>>>>>>>
>>>>>>>> public class CDOViewImpl extends
>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>> {
>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>> {
>>>>>>>> return featureAnalyzer;
>>>>>>>> }
>>>>>>>>
>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>> featureAnalyzer)
>>>>>>>> {
>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>> }
>>>>>>>>
>>>>>>>>
>>>>>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>>>>>> Simon). - Caches can be configured
>>>>>>>> - ...
>>>>>>>>
>>>>>>>>
>>>>>>>> Known issues of the DBStore:
>>>>>>>> - When in auditing mode updates are always written as complete
>>>>>>>> inserts (by design) - When configuring toManyReferences to a value
>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented yet) it
>>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>>>> others...
>>>>>>>>
>>>>>>>> Please note that the DBStore was not written by me to compete with
>>>>>>>> Hibernate in terms of performance or mapping capabilities. Now
>>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>>> HibernateStore and this HibernateStore gets more and more features
>>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>>
>>>>>>>>
>>>>>>>> This is probably linked to the way the mapping to db is done, here's
>>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>>> correctly).
>>>>>>>>
>>>>>>>>
>>>>>>>> <repository name="repo1">
>>>>>>>> <property name="overrideUUID"
>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>> <property name="supportingAudits" value="true"/>
>>>>>>>> <property name="verifyingRevisions" value="false"/>
>>>>>>>> <property name="currentLRUCapacity" value="10000"/>
>>>>>>>> I guess this one could be larger.
>>>>>>>>
>>>>>>>>
>>>>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>>>>
>>>>>>>> <store type="db">
>>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>>> user-contributed type> --> <mappingStrategy
>>>>>>>> type="horizontal">
>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY | LIKE_ATTRIBUTES
>>>>>>>> -->
>>>>>>>> <property name="toManyReferences"
>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>
>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>> <property name="toOneReferences"
>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>
>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>> <property name="mappingPrecedence"
>>>>>>>> value="MODEL"/>
>>>>>>>> This one is obsolete.
>>>>>>>>
>>>>>>>>
>>>>>>>> </mappingStrategy>
>>>>>>>>
>>>>>>>> <dbAdapter name="derby-embedded"/>
>>>>>>>> <dataSource
>>>>>>>>
>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>>> createDatabase="create"/>
>>>>>>>>
>>>>>>>> </store>
>>>>>>>> </repository>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> What do you think about that ? What throughput do you think I should
>>>>>>>> expect ? As I said that's very difficult to judge.
>>>>>>>> I believe it's more appropriate to compare the actual values with
>>>>>>>> values from other measures (other setups, properties, etc. or even
>>>>>>>> other products) instead of random expectations. Apologies that I
>>>>>>>> didn't have the time so far to provide some reference measures
>>>>>>>> myself. Maybe this gets better now that the team starts to grow
>>>>>>>> slowly ;-)
>>>>>>>>
>>>>>>>>
>>>>>>>> What are the main reasons fur such figures ?
>>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>>> evidence your assessment ;-)
>>>>>>>>
>>>>>>>> Ahh,one more note:
>>>>>>>> Tracing can also have a significant impact on performance and
>>>>>>>> end-to-end throughput. Turn it off by all means. And please make
>>>>>>>> sure that it's really turned off, not only invisible (i.e. console
>>>>>>>> is not a target).
>>>>>>>>
>>>>>>>> Cheers
>>>>>>>> /Eike
>>
>


--

With Regards, Martin Taal

Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
Re: [CDO] reading/writting throughput performances [message #124496 is a reply to message #124481] Sun, 01 June 2008 04:41 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

This is a multi-part message in MIME format.
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Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Hi guys,

I can confirm, making these 3rd party libraries with their own
classloading run in OSGi is a nightmare! I took me hours teach where the
hsqldb driver is. On the way I came over different kinds of classloading
related errors.

First I removed all the jars from the test plugin (the one Cedric
provided). They're already in the cdo.server.hibernate.libraries plugin
which, in fact, needs the buddy policy set to dependent. I think this
last change needs to be committed to CVS! Btw. I'd prefer to use
*registered* buddies instead of making all dependent bundles visible.

The test plugin then needs to provide the database driver. Therefore I
added a dependency on the org.eclipse.net4j.db.hsqldb plugin.

With this setup I can start the server without CNFE, NCDFE, CCI and the
like. At this point I get the following exception, which seems the same
as the one Cedric observed in the end:

net.sf.cglib.core.CodeGenerationException:
java.lang.reflect.InvocationTargetException-->null
at
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
at
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
at
org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
at
org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
at
org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
at
org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
at
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
at
org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
at
org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
at
org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
at
org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
at
org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
at
org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
at
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
at
org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
at
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
at
org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
at
org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
at
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
at
org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
at org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
at junit.framework.TestCase.runBare(TestCase.java:128)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:120)
at junit.framework.TestSuite.runTest(TestSuite.java:230)
at junit.framework.TestSuite.run(TestSuite.java:225)
at
org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
at
org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
at
org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at
org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
at
org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
at
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
... 61 more
Caused by: java.lang.NoClassDefFoundError:
org/hibernate/proxy/HibernateProxy
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
... 67 more

I must admit that I'm still not sure about te fundamental interwork
between Hibernate and the user defined meta model. It seems as if asm
and cglib are somewhere in between but I have no idea why at all. I
thought we have implemented a bunch of static Hibernate interfaces to
make the CDORevision instances known to Hibernate. Please somebody
explain why we need runtime byte code engineering? Is there some
configuration missing to tell Hibernate to use our special tuplizers?

I have changed several things in the code of the test plugin and since
it's quite small now that the jars are removed, I attach my version of
the zip here (including a JUnit Plugin launch config). And don't forget
to update the cdo.server.hibernate.libraries plugin from CVS to get the
new buddy policy!

Cheers
/Eike

Martin Taal schrieb:
> Hi Cédric,
> I looked at it for many hours trying different things (using your
> testcase) but I am kind of stuck with this (getting the same error as
> you). The difference I can see with the way I run the cdo.hibernate
> testcases (as a junit test) and how your testcase is run (junit plugin
> test). This for sure means difference in class loader behavior.
>
> Eike, do you have an idea? I am not sure how classloading works when
> you start a cdo server in a plugin. Which plugins are then available
> in the cdo server? The testcases can be downloaded from the link below.
>
> gr. Martin
>
> Cédric Brun wrote:
>> Thanks a lot ! I'm looking forward to your advices !
>>
>> Cédric
>>
>> Martin Taal wrote:
>>
>>> I am downloading your zip-file. I don't have time to look at it
>>> right away
>>> but I will do my best later this evening.
>>>
>>> gr. Martin
>>>
>>> Cédric Brun wrote:
>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>
>>>> Here's a zipped project trying to launch an HibernateServer with a
>>>> unit
>>>> test adding elements.
>>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>> The
>>>> libs I found are included in the same project, but I still have no
>>>> luck
>>>> and failling at :
>>>>
>>>> at
>>>>
>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>
>>>> ... 62 more
>>>> Caused by: java.lang.NoClassDefFoundError:
>>>> org/hibernate/proxy/HibernateProxy
>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>> ... 68 more
>>>>
>>>> please note that the test project I provide really is a "quick and
>>>> ugly"
>>>> one ^^
>>>>
>>>>
>>>> Cédric
>>>>
>>>>
>>>>
>>>> Martin Taal wrote:
>>>>
>>>>> Hmm, I can understand your headache. Classpath issues are the most
>>>>> annoying errors...
>>>>>
>>>>> In your junit test source file, what happens when you enter the
>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>
>>>>> What I also find slightly strange is that cglib is used in this case
>>>>> because normally cdo objects are not proxied using cglib. Can you
>>>>> post
>>>>> the generated mapping? How does your cdo initialization code look
>>>>> like?
>>>>>
>>>>> gr. Martin
>>>>>
>>>>> Cédric Brun wrote:
>>>>>> Hi Martin,
>>>>>>
>>>>>> and thanks for your quick answer ! what I did is the following :
>>>>>>
>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle and
>>>>>> added that :
>>>>>>
>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>> lib/cglib-2.1.3.jar,
>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>> lib/dom4j.jar,
>>>>>> lib/jta.jar
>>>>>> lib/asm-3.0.jar
>>>>>>
>>>>>> and this directive :
>>>>>>
>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>
>>>>>> as stated in
>>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>
>>>>>> Then I don't get the same error, now when I start my own plugin
>>>>>> (JUnit
>>>>>> plugin test) depending on
>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>
>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>> at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>> at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>> at
>>>>>>
>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>
>>>>>> These jars are such a headache ! Do you know - by chance - what's
>>>>>> going on ?
>>>>>>
>>>>>>
>>>>>> Cédric
>>>>>>
>>>>>>
>>>>>> Martin Taal wrote:
>>>>>>
>>>>>>> Hi Cédric,
>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>> can't find
>>>>>>> the class. A common cause is that the hibernate jar files are
>>>>>>> located
>>>>>>> in a separate plugin which can not reach the classes in other
>>>>>>> plugins.
>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>> dependent then this can help.
>>>>>>>
>>>>>>> gr. Martin
>>>>>>>
>>>>>>> Cédric Brun wrote:
>>>>>>>> Hi Simon and Eike,
>>>>>>>>
>>>>>>>> thanks for your feedback, now I know what I could expect in using
>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>> store and
>>>>>>>> see if it is scaling in a better way.
>>>>>>>>
>>>>>>>> You gave me many pointers to explain the performances issues
>>>>>>>> but in
>>>>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>
>>>>>>>> So I'm installing the hibernate store retrieving all the source
>>>>>>>> code
>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added many
>>>>>>>> jars
>>>>>>>> and everything gets compiled but most of the tests are failling
>>>>>>>> with
>>>>>>>> "
>>>>>>>>
>>>>>>>> "
>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>
>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>>> at table: cdo_features, for columns:
>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>
>>>>>>>> any hint ?
>>>>>>>>
>>>>>>>> Cédric
>>>>>>>>
>>>>>>>>
>>>>>>>> Simon McDuff wrote:
>>>>>>>>
>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>
>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>> collections that
>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>
>>>>>>>>> Model:
>>>>>>>>>
>>>>>>>>> ClassB
>>>>>>>>> {
>>>>>>>>> int foo1;
>>>>>>>>> List childrens1;
>>>>>>>>> List childrens2;
>>>>>>>>> List childrens3;
>>>>>>>>> };
>>>>>>>>>
>>>>>>>>> Code:
>>>>>>>>>
>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>
>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>> items in
>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem we
>>>>>>>>> had.. is
>>>>>>>>> we do not know if we want to use it. SO better not to download
>>>>>>>>> them.
>>>>>>>>>
>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>> download any
>>>>>>>>> objects from collection. I'm working at the moment to put in
>>>>>>>>> place
>>>>>>>>> all feature we used in the current CDO. That one will be part of
>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>
>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>> Worst case :
>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>
>>>>>>>>> Best case
>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the case of
>>>>>>>>> the filesystem)
>>>>>>>>>
>>>>>>>>> (These statistics always fetch objects from server to client. The
>>>>>>>>> cache client isn't used)
>>>>>>>>>
>>>>>>>>> We have another optimization one with SmartReadAhead but for now
>>>>>>>>> only work
>>>>>>>>> for UI client. (for now) This is something we will integrate as
>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>
>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>> without CDO.
>>>>>>>>> I compare
>>>>>>>>>
>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>>>
>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>
>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>> Derby)!!
>>>>>>>>> :-)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Another comments about insertion.
>>>>>>>>>
>>>>>>>>> We found another problem when we insert data(DOn't know if it is
>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>> each time
>>>>>>>>> we insert one element, it needs to fetch all the collection to
>>>>>>>>> see
>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>> consuming.
>>>>>>>>> In our case we are not going through this stage to persist our
>>>>>>>>> objects... but the objects are not accessible through that list.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> If speed is an issue for you!! We (You included :-)) can optimize
>>>>>>>>> it. What I like is Eike did a really good job doing that framwork
>>>>>>>>> and optimizations are easy to add. Also you can change your
>>>>>>>>> back-end
>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Simon
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le message de
>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>
>>>>>>>>> That sounds interesting!
>>>>>>>>> Comments inline...
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>> Hi Eike,
>>>>>>>>>
>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>> unit-tests measuring read/write throughput when I use CDO (RC2).
>>>>>>>>>
>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple one - 1
>>>>>>>>> Classifier/3 Features)
>>>>>>>>>
>>>>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>>>>> figures too seriously, I would just like to have your input about
>>>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>> acceptor but
>>>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>>>> Looks like a sign that the NIO socket channels are efficient
>>>>>>>>> ,-)
>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> * First case : building a small model (10000 elements) with the
>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per second
>>>>>>>>> rate.
>>>>>>>>> Seems to be consistent with the fact that only for commits
>>>>>>>>> there
>>>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>>>> starts with bigger transactions.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> browsing the just commited elements opening a new transaction and
>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>> objets/sec rate
>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>> All views and transactions of a single session share (and
>>>>>>>>> cache)
>>>>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached
>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>> (which you
>>>>>>>>> used) is not that optimized.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>> complex metamodel. It contains 700 000 elements. The creation
>>>>>>>>> went
>>>>>>>>> pretty nicely (I did not measured it exactly as it was launched
>>>>>>>>> during a night, but it seems I got around 100 objects/sec rate in
>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>> Sounds not too bad.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Once the model is built the derby database is 222 MB (which - I
>>>>>>>>> heard - is not so big for derby).
>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>> To be honest, I'm really no database expert (although I can
>>>>>>>>> write
>>>>>>>>> simple SQL statements).
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Retrieving the distant resource and calling eAllContents() on
>>>>>>>>> it, I
>>>>>>>>> get a 50 Objects/sec rate at best, which mean my
>>>>>>>>> eAllContents() call
>>>>>>>>> would take 4 hours !
>>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>>> (iteration order and so). There are several CDO features
>>>>>>>>> that can
>>>>>>>>> have a major impact on load rates!
>>>>>>>>>
>>>>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>>>>> don't mean the target objects, which are lazy by default
>>>>>>>>> anyway,
>>>>>>>>> but even the target IDs that are in the collections. We call
>>>>>>>>> that
>>>>>>>>> "reference chunking" (but search for a better name is ongoing).
>>>>>>>>>
>>>>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>>>>> IContainer<CDOView>
>>>>>>>>> {
>>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>>
>>>>>>>>> public void setReferenceChunkSize(int
>>>>>>>>> referenceChunkSize);
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> - Loading collection elements (target objects) can be
>>>>>>>>> batched (the
>>>>>>>>> current name is even worse)
>>>>>>>>>
>>>>>>>>> public interface CDOView extends CDOProtocolView,
>>>>>>>>> INotifier
>>>>>>>>> {
>>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>>
>>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> - One of the most sophisticated feature is automatic model
>>>>>>>>> usage
>>>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>>>> server. When later objects are loaded from the server, it can
>>>>>>>>> answer with additional objects that are likely to be needed
>>>>>>>>> by the
>>>>>>>>> client in the near future.
>>>>>>>>>
>>>>>>>>> public class CDOViewImpl extends
>>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier implements
>>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>>> {
>>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>>> {
>>>>>>>>> return featureAnalyzer;
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>>> featureAnalyzer)
>>>>>>>>> {
>>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> - There's a SmartReadAheadThread (if you're curious, please ask
>>>>>>>>> Simon). - Caches can be configured
>>>>>>>>> - ...
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Known issues of the DBStore:
>>>>>>>>> - When in auditing mode updates are always written as complete
>>>>>>>>> inserts (by design) - When configuring toManyReferences to a
>>>>>>>>> value
>>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented
>>>>>>>>> yet) it
>>>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>>>>> others...
>>>>>>>>>
>>>>>>>>> Please note that the DBStore was not written by me to
>>>>>>>>> compete with
>>>>>>>>> Hibernate in terms of performance or mapping capabilities. Now
>>>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>>>>> features
>>>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> This is probably linked to the way the mapping to db is done,
>>>>>>>>> here's
>>>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>>>> correctly).
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> <repository name="repo1">
>>>>>>>>> <property name="overrideUUID"
>>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>>> <property name="supportingAudits" value="true"/>
>>>>>>>>> <property name="verifyingRevisions"
>>>>>>>>> value="false"/>
>>>>>>>>> <property name="currentLRUCapacity"
>>>>>>>>> value="10000"/>
>>>>>>>>> I guess this one could be larger.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> <property name="revisedLRUCapacity" value="100"/>
>>>>>>>>> <store type="db">
>>>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>>>> user-contributed type> -->
>>>>>>>>> <mappingStrategy
>>>>>>>>> type="horizontal">
>>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>>>> LIKE_ATTRIBUTES
>>>>>>>>> -->
>>>>>>>>> <property name="toManyReferences"
>>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>>
>>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>>> <property name="toOneReferences"
>>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>>
>>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>>> <property
>>>>>>>>> name="mappingPrecedence"
>>>>>>>>> value="MODEL"/>
>>>>>>>>> This one is obsolete.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> </mappingStrategy>
>>>>>>>>> <dbAdapter
>>>>>>>>> name="derby-embedded"/>
>>>>>>>>> <dataSource
>>>>>>>>>
>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>>>> createDatabase="create"/>
>>>>>>>>>
>>>>>>>>> </store>
>>>>>>>>> </repository>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> What do you think about that ? What throughput do you think I
>>>>>>>>> should
>>>>>>>>> expect ? As I said that's very difficult to judge.
>>>>>>>>> I believe it's more appropriate to compare the actual values
>>>>>>>>> with
>>>>>>>>> values from other measures (other setups, properties, etc.
>>>>>>>>> or even
>>>>>>>>> other products) instead of random expectations. Apologies
>>>>>>>>> that I
>>>>>>>>> didn't have the time so far to provide some reference measures
>>>>>>>>> myself. Maybe this gets better now that the team starts to grow
>>>>>>>>> slowly ;-)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> What are the main reasons fur such figures ?
>>>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>>>> evidence your assessment ;-)
>>>>>>>>>
>>>>>>>>> Ahh,one more note:
>>>>>>>>> Tracing can also have a significant impact on performance and
>>>>>>>>> end-to-end throughput. Turn it off by all means. And please
>>>>>>>>> make
>>>>>>>>> sure that it's really turned off, not only invisible (i.e.
>>>>>>>>> console
>>>>>>>>> is not a target).
>>>>>>>>>
>>>>>>>>> Cheers
>>>>>>>>> /Eike
>>>
>>
>
>

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L1Td
Re: [CDO] reading/writting throughput performances [message #124519 is a reply to message #124496] Sun, 01 June 2008 08:17 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

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Hi,

Here is a diagram of the dependencies of the relevant plugins (please
correct me if something is wrong).
The black arrows are ordinary downstream dependencies (Require-Bundle).
The red arrows are upstream dependencies (Eclipse-BuddyPolicy: dependent).



For research purposes I added code to the libraries plugin that tries to
reflectively load CDOFeatureImpl and that is not a problem!
It seems to me as if our problem is not class loading related because
the hibernate.jar should be able to see the needed classes.
I believe this is either a bug in Hibernate or our wrong usage of
Hibernate. I tend to believe the latter ;-)
I put a breakpoint in
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
EntityMetamodel)
to see how the tuplizers are created. I'm too unexperienced with
Hibernate to get a clue about what happens there...

Btw. I'd prefer to see the application plugin depend on net4j.db instead
of net4j.db.hsqldb.
But it seems as if the BuddyPolicy in net4j.db is not "reexported" so
that the application can see the hsqldb.jar then ;-(
I posted a respective question to equinox...

Cheers
/Eike


Eike Stepper schrieb:
> Hi guys,
>
> I can confirm, making these 3rd party libraries with their own
> classloading run in OSGi is a nightmare! I took me hours teach where
> the hsqldb driver is. On the way I came over different kinds of
> classloading related errors.
>
> First I removed all the jars from the test plugin (the one Cedric
> provided). They're already in the cdo.server.hibernate.libraries
> plugin which, in fact, needs the buddy policy set to dependent. I
> think this last change needs to be committed to CVS! Btw. I'd prefer
> to use *registered* buddies instead of making all dependent bundles
> visible.
>
> The test plugin then needs to provide the database driver. Therefore I
> added a dependency on the org.eclipse.net4j.db.hsqldb plugin.
>
> With this setup I can start the server without CNFE, NCDFE, CCI and
> the like. At this point I get the following exception, which seems the
> same as the one Cedric observed in the end:
>
> net.sf.cglib.core.CodeGenerationException:
> java.lang.reflect.InvocationTargetException-->null
> at
> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
>
> at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
> at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
> at
> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
>
> at
> org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
>
> at
> org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
>
> at
> org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
>
> at
> org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
>
> at
> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
>
> at
> org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
>
> at
> org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
>
> at
> org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
>
> at
> org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
>
> at
> org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
> at
> org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
>
> at
> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
>
> at
> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
>
> at
> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
>
> at
> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
>
> at
> org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
>
> at
> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>
> at
> org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
>
> at
> org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
>
> at
> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>
> at
> org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
>
> at
> org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
> at junit.framework.TestCase.runBare(TestCase.java:128)
> at junit.framework.TestResult$1.protect(TestResult.java:106)
> at junit.framework.TestResult.runProtected(TestResult.java:124)
> at junit.framework.TestResult.run(TestResult.java:109)
> at junit.framework.TestCase.run(TestCase.java:120)
> at junit.framework.TestSuite.runTest(TestSuite.java:230)
> at junit.framework.TestSuite.run(TestSuite.java:225)
> at
> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>
> at
> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>
> at
> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>
> at
> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at
> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
>
> at
> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>
> at
> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
>
> at
> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
>
> at
> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
>
> at
> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
>
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
> at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
> at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
> Caused by: java.lang.reflect.InvocationTargetException
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
> at
> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>
> ... 61 more
> Caused by: java.lang.NoClassDefFoundError:
> org/hibernate/proxy/HibernateProxy
> at java.lang.ClassLoader.defineClass1(Native Method)
> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
> ... 67 more
>
> I must admit that I'm still not sure about te fundamental interwork
> between Hibernate and the user defined meta model. It seems as if asm
> and cglib are somewhere in between but I have no idea why at all. I
> thought we have implemented a bunch of static Hibernate interfaces to
> make the CDORevision instances known to Hibernate. Please somebody
> explain why we need runtime byte code engineering? Is there some
> configuration missing to tell Hibernate to use our special tuplizers?
>
> I have changed several things in the code of the test plugin and since
> it's quite small now that the jars are removed, I attach my version of
> the zip here (including a JUnit Plugin launch config). And don't
> forget to update the cdo.server.hibernate.libraries plugin from CVS to
> get the new buddy policy!
>
> Cheers
> /Eike
>
> Martin Taal schrieb:
>> Hi Cédric,
>> I looked at it for many hours trying different things (using your
>> testcase) but I am kind of stuck with this (getting the same error as
>> you). The difference I can see with the way I run the cdo.hibernate
>> testcases (as a junit test) and how your testcase is run (junit
>> plugin test). This for sure means difference in class loader behavior.
>>
>> Eike, do you have an idea? I am not sure how classloading works when
>> you start a cdo server in a plugin. Which plugins are then available
>> in the cdo server? The testcases can be downloaded from the link below.
>>
>> gr. Martin
>>
>> Cédric Brun wrote:
>>> Thanks a lot ! I'm looking forward to your advices !
>>>
>>> Cédric
>>>
>>> Martin Taal wrote:
>>>
>>>> I am downloading your zip-file. I don't have time to look at it
>>>> right away
>>>> but I will do my best later this evening.
>>>>
>>>> gr. Martin
>>>>
>>>> Cédric Brun wrote:
>>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>>
>>>>> Here's a zipped project trying to launch an HibernateServer with a
>>>>> unit
>>>>> test adding elements.
>>>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>>> The
>>>>> libs I found are included in the same project, but I still have no
>>>>> luck
>>>>> and failling at :
>>>>>
>>>>> at
>>>>>
>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>
>>>>> ... 62 more
>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>> org/hibernate/proxy/HibernateProxy
>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>> ... 68 more
>>>>>
>>>>> please note that the test project I provide really is a "quick and
>>>>> ugly"
>>>>> one ^^
>>>>>
>>>>>
>>>>> Cédric
>>>>>
>>>>>
>>>>>
>>>>> Martin Taal wrote:
>>>>>
>>>>>> Hmm, I can understand your headache. Classpath issues are the most
>>>>>> annoying errors...
>>>>>>
>>>>>> In your junit test source file, what happens when you enter the
>>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>>
>>>>>> What I also find slightly strange is that cglib is used in this case
>>>>>> because normally cdo objects are not proxied using cglib. Can you
>>>>>> post
>>>>>> the generated mapping? How does your cdo initialization code look
>>>>>> like?
>>>>>>
>>>>>> gr. Martin
>>>>>>
>>>>>> Cédric Brun wrote:
>>>>>>> Hi Martin,
>>>>>>>
>>>>>>> and thanks for your quick answer ! what I did is the following :
>>>>>>>
>>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle
>>>>>>> and
>>>>>>> added that :
>>>>>>>
>>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>>> lib/cglib-2.1.3.jar,
>>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>>> lib/dom4j.jar,
>>>>>>> lib/jta.jar
>>>>>>> lib/asm-3.0.jar
>>>>>>>
>>>>>>> and this directive :
>>>>>>>
>>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>>
>>>>>>> as stated in
>>>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>>
>>>>>>>
>>>>>>> Then I don't get the same error, now when I start my own plugin
>>>>>>> (JUnit
>>>>>>> plugin test) depending on
>>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>>
>>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>>> at
>>>>>>> net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>>> at
>>>>>>> net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>>> at
>>>>>>>
>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>
>>>>>>> These jars are such a headache ! Do you know - by chance - what's
>>>>>>> going on ?
>>>>>>>
>>>>>>>
>>>>>>> Cédric
>>>>>>>
>>>>>>>
>>>>>>> Martin Taal wrote:
>>>>>>>
>>>>>>>> Hi Cédric,
>>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>>> can't find
>>>>>>>> the class. A common cause is that the hibernate jar files are
>>>>>>>> located
>>>>>>>> in a separate plugin which can not reach the classes in other
>>>>>>>> plugins.
>>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>>> dependent then this can help.
>>>>>>>>
>>>>>>>> gr. Martin
>>>>>>>>
>>>>>>>> Cédric Brun wrote:
>>>>>>>>> Hi Simon and Eike,
>>>>>>>>>
>>>>>>>>> thanks for your feedback, now I know what I could expect in using
>>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>>> store and
>>>>>>>>> see if it is scaling in a better way.
>>>>>>>>>
>>>>>>>>> You gave me many pointers to explain the performances issues
>>>>>>>>> but in
>>>>>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>>
>>>>>>>>> So I'm installing the hibernate store retrieving all the
>>>>>>>>> source code
>>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added
>>>>>>>>> many jars
>>>>>>>>> and everything gets compiled but most of the tests are
>>>>>>>>> failling with
>>>>>>>>> "
>>>>>>>>>
>>>>>>>>> "
>>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>>
>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>>>> at table: cdo_features, for columns:
>>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>>
>>>>>>>>> any hint ?
>>>>>>>>>
>>>>>>>>> Cédric
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Simon McDuff wrote:
>>>>>>>>>
>>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>>
>>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>>> collections that
>>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>>
>>>>>>>>>> Model:
>>>>>>>>>>
>>>>>>>>>> ClassB
>>>>>>>>>> {
>>>>>>>>>> int foo1;
>>>>>>>>>> List childrens1;
>>>>>>>>>> List childrens2;
>>>>>>>>>> List childrens3;
>>>>>>>>>> };
>>>>>>>>>>
>>>>>>>>>> Code:
>>>>>>>>>>
>>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>>
>>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>>> items in
>>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem we
>>>>>>>>>> had.. is
>>>>>>>>>> we do not know if we want to use it. SO better not to
>>>>>>>>>> download them.
>>>>>>>>>>
>>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>>> download any
>>>>>>>>>> objects from collection. I'm working at the moment to put in
>>>>>>>>>> place
>>>>>>>>>> all feature we used in the current CDO. That one will be part of
>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>>
>>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>>> Worst case :
>>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>>
>>>>>>>>>> Best case
>>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the
>>>>>>>>>> case of
>>>>>>>>>> the filesystem)
>>>>>>>>>>
>>>>>>>>>> (These statistics always fetch objects from server to client.
>>>>>>>>>> The
>>>>>>>>>> cache client isn't used)
>>>>>>>>>>
>>>>>>>>>> We have another optimization one with SmartReadAhead but for now
>>>>>>>>>> only work
>>>>>>>>>> for UI client. (for now) This is something we will integrate as
>>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>>
>>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>>> without CDO.
>>>>>>>>>> I compare
>>>>>>>>>>
>>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>>>>
>>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>>
>>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>>> Derby)!!
>>>>>>>>>> :-)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Another comments about insertion.
>>>>>>>>>>
>>>>>>>>>> We found another problem when we insert data(DOn't know if it is
>>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>>> each time
>>>>>>>>>> we insert one element, it needs to fetch all the collection
>>>>>>>>>> to see
>>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>>> consuming.
>>>>>>>>>> In our case we are not going through this stage to persist our
>>>>>>>>>> objects... but the objects are not accessible through that list.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> If speed is an issue for you!! We (You included :-)) can
>>>>>>>>>> optimize
>>>>>>>>>> it. What I like is Eike did a really good job doing that
>>>>>>>>>> framwork
>>>>>>>>>> and optimizations are easy to add. Also you can change your
>>>>>>>>>> back-end
>>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Simon
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le
>>>>>>>>>> message de
>>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>>
>>>>>>>>>> That sounds interesting!
>>>>>>>>>> Comments inline...
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>>> Hi Eike,
>>>>>>>>>>
>>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>>> unit-tests measuring read/write throughput when I use CDO (RC2).
>>>>>>>>>>
>>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple one
>>>>>>>>>> - 1
>>>>>>>>>> Classifier/3 Features)
>>>>>>>>>>
>>>>>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>>>>>> figures too seriously, I would just like to have your input
>>>>>>>>>> about
>>>>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>>> acceptor but
>>>>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>>>>> Looks like a sign that the NIO socket channels are
>>>>>>>>>> efficient ,-)
>>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> * First case : building a small model (10000 elements) with the
>>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per second
>>>>>>>>>> rate.
>>>>>>>>>> Seems to be consistent with the fact that only for commits
>>>>>>>>>> there
>>>>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>>>>> starts with bigger transactions.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> browsing the just commited elements opening a new transaction
>>>>>>>>>> and
>>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>>> objets/sec rate
>>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>>> All views and transactions of a single session share (and
>>>>>>>>>> cache)
>>>>>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached
>>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>>> (which you
>>>>>>>>>> used) is not that optimized.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>>> complex metamodel. It contains 700 000 elements. The creation
>>>>>>>>>> went
>>>>>>>>>> pretty nicely (I did not measured it exactly as it was launched
>>>>>>>>>> during a night, but it seems I got around 100 objects/sec
>>>>>>>>>> rate in
>>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>>> Sounds not too bad.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Once the model is built the derby database is 222 MB (which - I
>>>>>>>>>> heard - is not so big for derby).
>>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>>> To be honest, I'm really no database expert (although I can
>>>>>>>>>> write
>>>>>>>>>> simple SQL statements).
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Retrieving the distant resource and calling eAllContents() on
>>>>>>>>>> it, I
>>>>>>>>>> get a 50 Objects/sec rate at best, which mean my
>>>>>>>>>> eAllContents() call
>>>>>>>>>> would take 4 hours !
>>>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>>>> (iteration order and so). There are several CDO features
>>>>>>>>>> that can
>>>>>>>>>> have a major impact on load rates!
>>>>>>>>>>
>>>>>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>>>>>> don't mean the target objects, which are lazy by default
>>>>>>>>>> anyway,
>>>>>>>>>> but even the target IDs that are in the collections. We
>>>>>>>>>> call that
>>>>>>>>>> "reference chunking" (but search for a better name is
>>>>>>>>>> ongoing).
>>>>>>>>>>
>>>>>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>>>>>> IContainer<CDOView>
>>>>>>>>>> {
>>>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>>>
>>>>>>>>>> public void setReferenceChunkSize(int
>>>>>>>>>> referenceChunkSize);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> - Loading collection elements (target objects) can be
>>>>>>>>>> batched (the
>>>>>>>>>> current name is even worse)
>>>>>>>>>>
>>>>>>>>>> public interface CDOView extends CDOProtocolView,
>>>>>>>>>> INotifier
>>>>>>>>>> {
>>>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>>>
>>>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> - One of the most sophisticated feature is automatic model
>>>>>>>>>> usage
>>>>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>>>>> server. When later objects are loaded from the server, it can
>>>>>>>>>> answer with additional objects that are likely to be needed
>>>>>>>>>> by the
>>>>>>>>>> client in the near future.
>>>>>>>>>>
>>>>>>>>>> public class CDOViewImpl extends
>>>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier
>>>>>>>>>> implements
>>>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>>>> {
>>>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>>>> {
>>>>>>>>>> return featureAnalyzer;
>>>>>>>>>> }
>>>>>>>>>>
>>>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>>>> featureAnalyzer)
>>>>>>>>>> {
>>>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>>>> }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> - There's a SmartReadAheadThread (if you're curious, please
>>>>>>>>>> ask
>>>>>>>>>> Simon). - Caches can be configured
>>>>>>>>>> - ...
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Known issues of the DBStore:
>>>>>>>>>> - When in auditing mode updates are always written as complete
>>>>>>>>>> inserts (by design) - When configuring toManyReferences to
>>>>>>>>>> a value
>>>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented
>>>>>>>>>> yet) it
>>>>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>>>>>> others...
>>>>>>>>>>
>>>>>>>>>> Please note that the DBStore was not written by me to
>>>>>>>>>> compete with
>>>>>>>>>> Hibernate in terms of performance or mapping capabilities. Now
>>>>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>>>>>> features
>>>>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> This is probably linked to the way the mapping to db is done,
>>>>>>>>>> here's
>>>>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>>>>> correctly).
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> <repository name="repo1">
>>>>>>>>>> <property name="overrideUUID"
>>>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>>>> <property name="supportingAudits" value="true"/>
>>>>>>>>>> <property name="verifyingRevisions"
>>>>>>>>>> value="false"/>
>>>>>>>>>> <property name="currentLRUCapacity"
>>>>>>>>>> value="10000"/>
>>>>>>>>>> I guess this one could be larger.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> <property name="revisedLRUCapacity"
>>>>>>>>>> value="100"/>
>>>>>>>>>> <store type="db">
>>>>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>>>>> user-contributed type> -->
>>>>>>>>>> <mappingStrategy
>>>>>>>>>> type="horizontal">
>>>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>>>>> LIKE_ATTRIBUTES
>>>>>>>>>> -->
>>>>>>>>>> <property
>>>>>>>>>> name="toManyReferences"
>>>>>>>>>>
>>>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>>>
>>>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>>>> <property name="toOneReferences"
>>>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>>>
>>>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>>>> <property
>>>>>>>>>> name="mappingPrecedence"
>>>>>>>>>> value="MODEL"/>
>>>>>>>>>> This one is obsolete.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> </mappingStrategy>
>>>>>>>>>> <dbAdapter
>>>>>>>>>> name="derby-embedded"/>
>>>>>>>>>> <dataSource
>>>>>>>>>>
>>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>>>>> createDatabase="create"/>
>>>>>>>>>>
>>>>>>>>>> </store>
>>>>>>>>>> </repository>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> What do you think about that ? What throughput do you think I
>>>>>>>>>> should
>>>>>>>>>> expect ? As I said that's very difficult to judge.
>>>>>>>>>> I believe it's more appropriate to compare the actual
>>>>>>>>>> values with
>>>>>>>>>> values from other measures (other setups, properties, etc.
>>>>>>>>>> or even
>>>>>>>>>> other products) instead of random expectations. Apologies
>>>>>>>>>> that I
>>>>>>>>>> didn't have the time so far to provide some reference measures
>>>>>>>>>> myself. Maybe this gets better now that the team starts to
>>>>>>>>>> grow
>>>>>>>>>> slowly ;-)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> What are the main reasons fur such figures ?
>>>>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>>>>> evidence your assessment ;-)
>>>>>>>>>>
>>>>>>>>>> Ahh,one more note:
>>>>>>>>>> Tracing can also have a significant impact on performance and
>>>>>>>>>> end-to-end throughput. Turn it off by all means. And please
>>>>>>>>>> make
>>>>>>>>>> sure that it's really turned off, not only invisible (i.e.
>>>>>>>>>> console
>>>>>>>>>> is not a target).
>>>>>>>>>>
>>>>>>>>>> Cheers
>>>>>>>>>> /Eike
>>>>
>>>
>>
>>

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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Hi,<br>
<br>
Here is a diagram of the dependencies of the relevant plugins (please
correct me if something is wrong).<br>
The black arrows are ordinary downstream dependencies (Require-Bundle).<br>
The red arrows are upstream dependencies (Eclipse-BuddyPolicy:
dependent).<br>
<br>
<img src="cid:part1.07020404.09020102@sympedia.de" alt=""><br>
<br>
For research purposes I added code to the libraries plugin that tries
to reflectively load CDOFeatureImpl and that is not a problem!<br>
It seems to me as if our problem is not class loading related because
the hibernate.jar should be able to see the needed classes.<br>
I believe this is either a bug in Hibernate or our wrong usage of
Hibernate. I tend to believe the latter ;-)<br>
I put a breakpoint in
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
EntityMetamodel) <br>
to see how the tuplizers are created. I'm too unexperienced with
Hibernate to get a clue about what happens there...<br>
<br>
Btw. I'd prefer to see the application plugin depend on net4j.db
instead of net4j.db.hsqldb.<br>
But it seems as if the BuddyPolicy in net4j.db is not "reexported" so
that the application can see the hsqldb.jar then ;-(<br>
I posted a respective question to equinox...<br>
<br>
Cheers<br>
/Eike<br>
<br>
<br>
Eike Stepper schrieb:
<blockquote cite="mid:g1t99s$tla$1@build.eclipse.org" type="cite">Hi
guys,
<br>
<br>
I can confirm, making these 3rd party libraries with their own
classloading run in OSGi is a nightmare! I took me hours teach where
the hsqldb driver is. On the way I came over different kinds of
classloading related errors.
<br>
<br>
First I removed all the jars from the test plugin (the one Cedric
provided). They're already in the cdo.server.hibernate.libraries plugin
which, in fact, needs the buddy policy set to dependent. I think this
last change needs to be committed to CVS! Btw. I'd prefer to use
*registered* buddies instead of making all dependent bundles visible.
<br>
<br>
The test plugin then needs to provide the database driver. Therefore I
added a dependency on the org.eclipse.net4j.db.hsqldb plugin.
<br>
<br>
With this setup I can start the server without CNFE, NCDFE, CCI and the
like. At this point I get the following exception, which seems the same
as the one Cedric observed in the end:
<br>
<br>
net.sf.cglib.core.CodeGenerationException:
java.lang.reflect.InvocationTargetException--&gt;null
<br>
   at
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
<br>
   at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
<br>
   at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
<br>
   at
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
<br>
   at
org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
<br>
   at
org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
<br>
   at
org.hibernate.tuple.entity.AbstractEntityTuplizer.&lt;in it&gt;(AbstractEntityTuplizer.java:135)
<br>
   at
org.hibernate.tuple.entity.PojoEntityTuplizer.&lt;init&a mp;gt;(PojoEntityTuplizer.java:55)
<br>
   at
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .&lt;init&gt;(EntityEntityModeToTuplizerMapping.java :56)
<br>
   at
org.hibernate.tuple.entity.EntityMetamodel.&lt;init& gt;(EntityMetamodel.java:295)
<br>
   at
org.hibernate.persister.entity.AbstractEntityPersister.& lt;init&gt;(AbstractEntityPersister.java:434)
<br>
   at
org.hibernate.persister.entity.JoinedSubclassEntityPersister .&lt;init&gt;(JoinedSubclassEntityPersister.java:91)
<br>
   at
org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
<br>
   at
org.hibernate.impl.SessionFactoryImpl.&lt;init&gt;(S essionFactoryImpl.java:226)
<br>
   at
org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
<br>
   at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
<br>
   at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
<br>
   at
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
<br>
   at
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
<br>
   at
org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
<br>
   at
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
<br>
   at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
<br>
   at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
<br>
   at
org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
<br>
   at
org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
<br>
   at
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
<br>
   at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
<br>
   at
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
<br>
   at
org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
<br>
   at
org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
<br>
   at junit.framework.TestCase.runBare(TestCase.java:128)
<br>
   at junit.framework.TestResult$1.protect(TestResult.java:106)
<br>
   at junit.framework.TestResult.runProtected(TestResult.java:124)
<br>
   at junit.framework.TestResult.run(TestResult.java:109)
<br>
   at junit.framework.TestCase.run(TestCase.java:120)
<br>
   at junit.framework.TestSuite.runTest(TestSuite.java:230)
<br>
   at junit.framework.TestSuite.run(TestSuite.java:225)
<br>
   at
org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
<br>
   at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
<br>
   at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
<br>
   at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
<br>
   at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
<br>
   at
org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
<br>
   at
org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
<br>
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
<br>
   at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
<br>
   at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
<br>
   at java.lang.reflect.Method.invoke(Method.java:585)
<br>
   at
org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
<br>
   at
org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
<br>
   at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
<br>
   at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
<br>
   at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
<br>
   at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
<br>
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
<br>
   at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
<br>
   at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
<br>
   at java.lang.reflect.Method.invoke(Method.java:585)
<br>
   at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
<br>
   at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
<br>
   at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
<br>
   at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
<br>
Caused by: java.lang.reflect.InvocationTargetException
<br>
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
<br>
   at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
<br>
   at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
<br>
   at java.lang.reflect.Method.invoke(Method.java:585)
<br>
   at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
<br>
   at
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
<br>
   ... 61 more
<br>
Caused by: java.lang.NoClassDefFoundError:
org/hibernate/proxy/HibernateProxy
<br>
   at java.lang.ClassLoader.defineClass1(Native Method)
<br>
   at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
<br>
   ... 67 more
<br>
<br>
I must admit that I'm still not sure about te fundamental interwork
between Hibernate and the user defined meta model. It seems as if asm
and cglib are somewhere in between but I have no idea why at all. I
thought we have implemented a bunch of static Hibernate interfaces to
make the CDORevision instances known to Hibernate. Please somebody
explain why we need runtime byte code engineering? Is there some
configuration missing to tell Hibernate to use our special tuplizers?
<br>
<br>
I have changed several things in the code of the test plugin and since
it's quite small now that the jars are removed, I attach my version of
the zip here (including a JUnit Plugin launch config). And don't forget
to update the cdo.server.hibernate.libraries plugin from CVS to get the
new buddy policy!
<br>
<br>
Cheers
<br>
/Eike
<br>
<br>
Martin Taal schrieb:
<br>
<blockquote type="cite">Hi Cédric,
<br>
I looked at it for many hours trying different things (using your
testcase) but I am kind of stuck with this (getting the same error as
you). The difference I can see with the way I run the cdo.hibernate
testcases (as a junit test) and how your testcase is run (junit plugin
test). This for sure means difference in class loader behavior.
<br>
<br>
Eike, do you have an idea? I am
Re: [CDO] reading/writting throughput performances [message #124535 is a reply to message #124519] Sun, 01 June 2008 10:06 Go to previous messageGo to next message
Martin Taal is currently offline Martin TaalFriend
Messages: 5468
Registered: July 2009
Senior Member
Hi Eike, Cedric,
I can't say to much about net4j.db versus net4j.db.hsqldb.

You are correct that the hibernate.libraries plugin should have Eclipse-BuddyPolicy: dependent (or
another way to use the classpath of the dependent plugins). Btw, I agree that registered is better
as afaik dependent gets slow which larger plugin environments.

The reason that cglib is used is because one of the class mappings in
org.eclipse.emf.cdo.server.hibernate/mappings/meta.hbm/xml did not have the lazy="false" directive.
I added this and now I get another exception (see below). So this 'solves' the problem. If you do a
get latest of this file then I think this problem is 'overcome'.

Overall I still do not see why it went wrong. As far as I can see the cglib library could not find
the hibernate class, which is strange as they are in the same plugin??
The cdo testcases don't have this problem and neither does Teneo.

As it does not occur anymore we can ignore it for now (not very satisfactory but there are other
things to do)... Unless someone else has an idea how to handle this ofcourse.

gr. Martin

java.lang.IllegalStateException: acceptor == null
at org.eclipse.net4j.internal.jvm.JVMClientConnector.doBeforeAc tivate(JVMClientConnector.java:57)
at org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:56)
at org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
at org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
at org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:260)
at org.eclipse.emf.internal.cdo.util.ChannelInjector.getConnect or(ChannelInjector.java:74)
at org.eclipse.emf.internal.cdo.util.ChannelInjector.process(Ch annelInjector.java:41)
at
org.eclipse.net4j.internal.util.container.ManagedContainer.p ostProcessElement(ManagedContainer.java:407)
at org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:259)
at org.eclipse.cdo.bug.hibernate.HibernateServer.createSession( HibernateServer.java:93)
at org.eclipse.cdo.bug.unit.LaunchServerTest.testStringValue(La unchServerTest.java:43)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at junit.framework.TestCase.runTest(TestCase.java:164)
at junit.framework.TestCase.runBare(TestCase.java:130)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:120)
at junit.framework.TestSuite.runTest(TestSuite.java:230)
at junit.framework.TestSuite.run(TestSuite.java:225)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
at org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
at org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hod(EclipseAppContainer.java:547)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:106)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:76)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:362)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:175)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 564)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
at org.eclipse.equinox.launcher.Main.run(Main.java:1251)
at org.eclipse.equinox.launcher.Main.main(Main.java:1227)



Eike Stepper wrote:
> Hi,
>
> Here is a diagram of the dependencies of the relevant plugins (please
> correct me if something is wrong).
> The black arrows are ordinary downstream dependencies (Require-Bundle).
> The red arrows are upstream dependencies (Eclipse-BuddyPolicy: dependent).
>
>
>
> For research purposes I added code to the libraries plugin that tries to
> reflectively load CDOFeatureImpl and that is not a problem!
> It seems to me as if our problem is not class loading related because
> the hibernate.jar should be able to see the needed classes.
> I believe this is either a bug in Hibernate or our wrong usage of
> Hibernate. I tend to believe the latter ;-)
> I put a breakpoint in
> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
> EntityMetamodel)
> to see how the tuplizers are created. I'm too unexperienced with
> Hibernate to get a clue about what happens there...
>
> Btw. I'd prefer to see the application plugin depend on net4j.db instead
> of net4j.db.hsqldb.
> But it seems as if the BuddyPolicy in net4j.db is not "reexported" so
> that the application can see the hsqldb.jar then ;-(
> I posted a respective question to equinox...
>
> Cheers
> /Eike
>
>
> Eike Stepper schrieb:
>> Hi guys,
>>
>> I can confirm, making these 3rd party libraries with their own
>> classloading run in OSGi is a nightmare! I took me hours teach where
>> the hsqldb driver is. On the way I came over different kinds of
>> classloading related errors.
>>
>> First I removed all the jars from the test plugin (the one Cedric
>> provided). They're already in the cdo.server.hibernate.libraries
>> plugin which, in fact, needs the buddy policy set to dependent. I
>> think this last change needs to be committed to CVS! Btw. I'd prefer
>> to use *registered* buddies instead of making all dependent bundles
>> visible.
>>
>> The test plugin then needs to provide the database driver. Therefore I
>> added a dependency on the org.eclipse.net4j.db.hsqldb plugin.
>>
>> With this setup I can start the server without CNFE, NCDFE, CCI and
>> the like. At this point I get the following exception, which seems the
>> same as the one Cedric observed in the end:
>>
>> net.sf.cglib.core.CodeGenerationException:
>> java.lang.reflect.InvocationTargetException-->null
>> at
>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
>>
>> at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
>> at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
>> at
>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
>>
>> at
>> org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
>>
>> at
>> org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
>>
>> at
>> org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
>>
>> at
>> org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
>>
>> at
>> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
>>
>> at
>> org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
>>
>> at
>> org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
>>
>> at
>> org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
>>
>> at
>> org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
>>
>> at
>> org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
>> at
>> org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
>>
>> at
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
>>
>> at
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
>>
>> at
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
>>
>> at
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
>>
>> at
>> org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
>>
>> at
>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>
>> at
>> org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
>>
>> at
>> org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
>>
>> at
>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>
>> at
>> org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
>>
>> at
>> org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
>> at junit.framework.TestCase.runBare(TestCase.java:128)
>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>> at junit.framework.TestResult.run(TestResult.java:109)
>> at junit.framework.TestCase.run(TestCase.java:120)
>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>> at junit.framework.TestSuite.run(TestSuite.java:225)
>> at
>> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>
>> at
>> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>
>> at
>> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at
>> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
>>
>> at
>> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>
>> at
>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
>>
>> at
>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
>>
>> at
>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
>>
>> at
>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
>>
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>> at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
>> at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
>> Caused by: java.lang.reflect.InvocationTargetException
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
>> at
>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>
>> ... 61 more
>> Caused by: java.lang.NoClassDefFoundError:
>> org/hibernate/proxy/HibernateProxy
>> at java.lang.ClassLoader.defineClass1(Native Method)
>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>> ... 67 more
>>
>> I must admit that I'm still not sure about te fundamental interwork
>> between Hibernate and the user defined meta model. It seems as if asm
>> and cglib are somewhere in between but I have no idea why at all. I
>> thought we have implemented a bunch of static Hibernate interfaces to
>> make the CDORevision instances known to Hibernate. Please somebody
>> explain why we need runtime byte code engineering? Is there some
>> configuration missing to tell Hibernate to use our special tuplizers?
>>
>> I have changed several things in the code of the test plugin and since
>> it's quite small now that the jars are removed, I attach my version of
>> the zip here (including a JUnit Plugin launch config). And don't
>> forget to update the cdo.server.hibernate.libraries plugin from CVS to
>> get the new buddy policy!
>>
>> Cheers
>> /Eike
>>
>> Martin Taal schrieb:
>>> Hi Cédric,
>>> I looked at it for many hours trying different things (using your
>>> testcase) but I am kind of stuck with this (getting the same error as
>>> you). The difference I can see with the way I run the cdo.hibernate
>>> testcases (as a junit test) and how your testcase is run (junit
>>> plugin test). This for sure means difference in class loader behavior.
>>>
>>> Eike, do you have an idea? I am not sure how classloading works when
>>> you start a cdo server in a plugin. Which plugins are then available
>>> in the cdo server? The testcases can be downloaded from the link below.
>>>
>>> gr. Martin
>>>
>>> Cédric Brun wrote:
>>>> Thanks a lot ! I'm looking forward to your advices !
>>>>
>>>> Cédric
>>>>
>>>> Martin Taal wrote:
>>>>
>>>>> I am downloading your zip-file. I don't have time to look at it
>>>>> right away
>>>>> but I will do my best later this evening.
>>>>>
>>>>> gr. Martin
>>>>>
>>>>> Cédric Brun wrote:
>>>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>>>
>>>>>> Here's a zipped project trying to launch an HibernateServer with a
>>>>>> unit
>>>>>> test adding elements.
>>>>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>>>> The
>>>>>> libs I found are included in the same project, but I still have no
>>>>>> luck
>>>>>> and failling at :
>>>>>>
>>>>>> at
>>>>>>
>>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>
>>>>>> ... 62 more
>>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>>> org/hibernate/proxy/HibernateProxy
>>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>>> ... 68 more
>>>>>>
>>>>>> please note that the test project I provide really is a "quick and
>>>>>> ugly"
>>>>>> one ^^
>>>>>>
>>>>>>
>>>>>> Cédric
>>>>>>
>>>>>>
>>>>>>
>>>>>> Martin Taal wrote:
>>>>>>
>>>>>>> Hmm, I can understand your headache. Classpath issues are the most
>>>>>>> annoying errors...
>>>>>>>
>>>>>>> In your junit test source file, what happens when you enter the
>>>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>>>
>>>>>>> What I also find slightly strange is that cglib is used in this case
>>>>>>> because normally cdo objects are not proxied using cglib. Can you
>>>>>>> post
>>>>>>> the generated mapping? How does your cdo initialization code look
>>>>>>> like?
>>>>>>>
>>>>>>> gr. Martin
>>>>>>>
>>>>>>> Cédric Brun wrote:
>>>>>>>> Hi Martin,
>>>>>>>>
>>>>>>>> and thanks for your quick answer ! what I did is the following :
>>>>>>>>
>>>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries bundle
>>>>>>>> and
>>>>>>>> added that :
>>>>>>>>
>>>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>>>> lib/cglib-2.1.3.jar,
>>>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>>>> lib/dom4j.jar,
>>>>>>>> lib/jta.jar
>>>>>>>> lib/asm-3.0.jar
>>>>>>>>
>>>>>>>> and this directive :
>>>>>>>>
>>>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>>>
>>>>>>>> as stated in
>>>>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>>>
>>>>>>>>
>>>>>>>> Then I don't get the same error, now when I start my own plugin
>>>>>>>> (JUnit
>>>>>>>> plugin test) depending on
>>>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>>>
>>>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>>>> at
>>>>>>>> net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>>>> at
>>>>>>>> net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>>>> at
>>>>>>>>
>>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>>
>>>>>>>> These jars are such a headache ! Do you know - by chance - what's
>>>>>>>> going on ?
>>>>>>>>
>>>>>>>>
>>>>>>>> Cédric
>>>>>>>>
>>>>>>>>
>>>>>>>> Martin Taal wrote:
>>>>>>>>
>>>>>>>>> Hi Cédric,
>>>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>>>> can't find
>>>>>>>>> the class. A common cause is that the hibernate jar files are
>>>>>>>>> located
>>>>>>>>> in a separate plugin which can not reach the classes in other
>>>>>>>>> plugins.
>>>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>>>> dependent then this can help.
>>>>>>>>>
>>>>>>>>> gr. Martin
>>>>>>>>>
>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>> Hi Simon and Eike,
>>>>>>>>>>
>>>>>>>>>> thanks for your feedback, now I know what I could expect in using
>>>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>>>> store and
>>>>>>>>>> see if it is scaling in a better way.
>>>>>>>>>>
>>>>>>>>>> You gave me many pointers to explain the performances issues
>>>>>>>>>> but in
>>>>>>>>>> fact it seems that the SQL execution is taking so much time (not
>>>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>>>
>>>>>>>>>> So I'm installing the hibernate store retrieving all the
>>>>>>>>>> source code
>>>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added
>>>>>>>>>> many jars
>>>>>>>>>> and everything gets compiled but most of the tests are
>>>>>>>>>> failling with
>>>>>>>>>> "
>>>>>>>>>>
>>>>>>>>>> "
>>>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>>>
>>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>>>>> at table: cdo_features, for columns:
>>>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>>>
>>>>>>>>>> any hint ?
>>>>>>>>>>
>>>>>>>>>> Cédric
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Simon McDuff wrote:
>>>>>>>>>>
>>>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>>>
>>>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>>>> collections that
>>>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>>>
>>>>>>>>>>> Model:
>>>>>>>>>>>
>>>>>>>>>>> ClassB
>>>>>>>>>>> {
>>>>>>>>>>> int foo1;
>>>>>>>>>>> List childrens1;
>>>>>>>>>>> List childrens2;
>>>>>>>>>>> List childrens3;
>>>>>>>>>>> };
>>>>>>>>>>>
>>>>>>>>>>> Code:
>>>>>>>>>>>
>>>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>>>
>>>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>>>> items in
>>>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem we
>>>>>>>>>>> had.. is
>>>>>>>>>>> we do not know if we want to use it. SO better not to
>>>>>>>>>>> download them.
>>>>>>>>>>>
>>>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>>>> download any
>>>>>>>>>>> objects from collection. I'm working at the moment to put in
>>>>>>>>>>> place
>>>>>>>>>>> all feature we used in the current CDO. That one will be part of
>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>>>
>>>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>>>> Worst case :
>>>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains the
>>>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>>>
>>>>>>>>>>> Best case
>>>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the
>>>>>>>>>>> case of
>>>>>>>>>>> the filesystem)
>>>>>>>>>>>
>>>>>>>>>>> (These statistics always fetch objects from server to client.
>>>>>>>>>>> The
>>>>>>>>>>> cache client isn't used)
>>>>>>>>>>>
>>>>>>>>>>> We have another optimization one with SmartReadAhead but for now
>>>>>>>>>>> only work
>>>>>>>>>>> for UI client. (for now) This is something we will integrate as
>>>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>>>
>>>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>>>> without CDO.
>>>>>>>>>>> I compare
>>>>>>>>>>>
>>>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>>>>>
>>>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>>>
>>>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>>>> Derby)!!
>>>>>>>>>>> :-)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Another comments about insertion.
>>>>>>>>>>>
>>>>>>>>>>> We found another problem when we insert data(DOn't know if it is
>>>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>>>> each time
>>>>>>>>>>> we insert one element, it needs to fetch all the collection
>>>>>>>>>>> to see
>>>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>>>> consuming.
>>>>>>>>>>> In our case we are not going through this stage to persist our
>>>>>>>>>>> objects... but the objects are not accessible through that list.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> If speed is an issue for you!! We (You included :-)) can
>>>>>>>>>>> optimize
>>>>>>>>>>> it. What I like is Eike did a really good job doing that
>>>>>>>>>>> framwork
>>>>>>>>>>> and optimizations are easy to add. Also you can change your
>>>>>>>>>>> back-end
>>>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Simon
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le
>>>>>>>>>>> message de
>>>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>>>
>>>>>>>>>>> That sounds interesting!
>>>>>>>>>>> Comments inline...
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>>>> Hi Eike,
>>>>>>>>>>>
>>>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>>>> unit-tests measuring read/write throughput when I use CDO (RC2).
>>>>>>>>>>>
>>>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple one
>>>>>>>>>>> - 1
>>>>>>>>>>> Classifier/3 Features)
>>>>>>>>>>>
>>>>>>>>>>> The test is a "quick and dirty" one so please do not take these
>>>>>>>>>>> figures too seriously, I would just like to have your input
>>>>>>>>>>> about
>>>>>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>>>> acceptor but
>>>>>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>>>>>> Looks like a sign that the NIO socket channels are
>>>>>>>>>>> efficient ,-)
>>>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> * First case : building a small model (10000 elements) with the
>>>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>>>> commiting change on every add I get a 2 objects per second rate.
>>>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per second
>>>>>>>>>>> rate.
>>>>>>>>>>> Seems to be consistent with the fact that only for commits
>>>>>>>>>>> there
>>>>>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>>>>>> starts with bigger transactions.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> browsing the just commited elements opening a new transaction
>>>>>>>>>>> and
>>>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>>>> objets/sec rate
>>>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>>>> All views and transactions of a single session share (and
>>>>>>>>>>> cache)
>>>>>>>>>>> their object state. Otherwise I'd expect much smaller values.
>>>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed) reached
>>>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>>>> (which you
>>>>>>>>>>> used) is not that optimized.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>>>> complex metamodel. It contains 700 000 elements. The creation
>>>>>>>>>>> went
>>>>>>>>>>> pretty nicely (I did not measured it exactly as it was launched
>>>>>>>>>>> during a night, but it seems I got around 100 objects/sec
>>>>>>>>>>> rate in
>>>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>>>> Sounds not too bad.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Once the model is built the derby database is 222 MB (which - I
>>>>>>>>>>> heard - is not so big for derby).
>>>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>>>> To be honest, I'm really no database expert (although I can
>>>>>>>>>>> write
>>>>>>>>>>> simple SQL statements).
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Retrieving the distant resource and calling eAllContents() on
>>>>>>>>>>> it, I
>>>>>>>>>>> get a 50 Objects/sec rate at best, which mean my
>>>>>>>>>>> eAllContents() call
>>>>>>>>>>> would take 4 hours !
>>>>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>>>>> (iteration order and so). There are several CDO features
>>>>>>>>>>> that can
>>>>>>>>>>> have a major impact on load rates!
>>>>>>>>>>>
>>>>>>>>>>> - Collections (xrefs and containment) can be loaded lazily. I
>>>>>>>>>>> don't mean the target objects, which are lazy by default
>>>>>>>>>>> anyway,
>>>>>>>>>>> but even the target IDs that are in the collections. We
>>>>>>>>>>> call that
>>>>>>>>>>> "reference chunking" (but search for a better name is
>>>>>>>>>>> ongoing).
>>>>>>>>>>>
>>>>>>>>>>> public interface CDOSession extends CDOProtocolSession,
>>>>>>>>>>> IContainer<CDOView>
>>>>>>>>>>> {
>>>>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>>>>
>>>>>>>>>>> public void setReferenceChunkSize(int
>>>>>>>>>>> referenceChunkSize);
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> - Loading collection elements (target objects) can be
>>>>>>>>>>> batched (the
>>>>>>>>>>> current name is even worse)
>>>>>>>>>>>
>>>>>>>>>>> public interface CDOView extends CDOProtocolView,
>>>>>>>>>>> INotifier
>>>>>>>>>>> {
>>>>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>>>>
>>>>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> - One of the most sophisticated feature is automatic model
>>>>>>>>>>> usage
>>>>>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>>>>>> server. When later objects are loaded from the server, it can
>>>>>>>>>>> answer with additional objects that are likely to be needed
>>>>>>>>>>> by the
>>>>>>>>>>> client in the near future.
>>>>>>>>>>>
>>>>>>>>>>> public class CDOViewImpl extends
>>>>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier
>>>>>>>>>>> implements
>>>>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>>>>> {
>>>>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>>>>> {
>>>>>>>>>>> return featureAnalyzer;
>>>>>>>>>>> }
>>>>>>>>>>>
>>>>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>>>>> featureAnalyzer)
>>>>>>>>>>> {
>>>>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>>>>> }
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> - There's a SmartReadAheadThread (if you're curious, please
>>>>>>>>>>> ask
>>>>>>>>>>> Simon). - Caches can be configured
>>>>>>>>>>> - ...
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Known issues of the DBStore:
>>>>>>>>>>> - When in auditing mode updates are always written as complete
>>>>>>>>>>> inserts (by design) - When configuring toManyReferences to
>>>>>>>>>>> a value
>>>>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented
>>>>>>>>>>> yet) it
>>>>>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) - Maybe
>>>>>>>>>>> others...
>>>>>>>>>>>
>>>>>>>>>>> Please note that the DBStore was not written by me to
>>>>>>>>>>> compete with
>>>>>>>>>>> Hibernate in terms of performance or mapping capabilities. Now
>>>>>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>>>>>>> features
>>>>>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> This is probably linked to the way the mapping to db is done,
>>>>>>>>>>> here's
>>>>>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>>>>>> correctly).
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> <repository name="repo1">
>>>>>>>>>>> <property name="overrideUUID"
>>>>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>>>>> <property name="supportingAudits" value="true"/>
>>>>>>>>>>> <property name="verifyingRevisions"
>>>>>>>>>>> value="false"/>
>>>>>>>>>>> <property name="currentLRUCapacity"
>>>>>>>>>>> value="10000"/>
>>>>>>>>>>> I guess this one could be larger.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> <property name="revisedLRUCapacity"
>>>>>>>>>>> value="100"/>
>>>>>>>>>>> <store type="db">
>>>>>>>>>>> <!-- type: horizontal | vertical | <any
>>>>>>>>>>> user-contributed type> -->
>>>>>>>>>>> <mappingStrategy
>>>>>>>>>>> type="horizontal">
>>>>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>>>>>> LIKE_ATTRIBUTES
>>>>>>>>>>> -->
>>>>>>>>>>> <property
>>>>>>>>>>> name="toManyReferences"
>>>>>>>>>>>
>>>>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>>>>
>>>>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>>>>> <property name="toOneReferences"
>>>>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>>>>
>>>>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>>>>> <property
>>>>>>>>>>> name="mappingPrecedence"
>>>>>>>>>>> value="MODEL"/>
>>>>>>>>>>> This one is obsolete.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> </mappingStrategy>
>>>>>>>>>>> <dbAdapter
>>>>>>>>>>> name="derby-embedded"/>
>>>>>>>>>>> <dataSource
>>>>>>>>>>>
>>>>>> class="org.apache.derby.jdbc.EmbeddedDataSource"
>>>>>>>>>>> databaseName="/tmp/cdodb1"
>>>>>>>>>>> createDatabase="create"/>
>>>>>>>>>>>
>>>>>>>>>>> </store>
>>>>>>>>>>> </repository>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> What do you think about that ? What throughput do you think I
>>>>>>>>>>> should
>>>>>>>>>>> expect ? As I said that's very difficult to judge.
>>>>>>>>>>> I believe it's more appropriate to compare the actual
>>>>>>>>>>> values with
>>>>>>>>>>> values from other measures (other setups, properties, etc.
>>>>>>>>>>> or even
>>>>>>>>>>> other products) instead of random expectations. Apologies
>>>>>>>>>>> that I
>>>>>>>>>>> didn't have the time so far to provide some reference measures
>>>>>>>>>>> myself. Maybe this gets better now that the team starts to
>>>>>>>>>>> grow
>>>>>>>>>>> slowly ;-)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> What are the main reasons fur such figures ?
>>>>>>>>>>> Hmm, I *suspect* you don't like the figures? I can find no
>>>>>>>>>>> evidence your assessment ;-)
>>>>>>>>>>>
>>>>>>>>>>> Ahh,one more note:
>>>>>>>>>>> Tracing can also have a significant impact on performance and
>>>>>>>>>>> end-to-end throughput. Turn it off by all means. And please
>>>>>>>>>>> make
>>>>>>>>>>> sure that it's really turned off, not only invisible (i.e.
>>>>>>>>>>> console
>>>>>>>>>>> is not a target).
>>>>>>>>>>>
>>>>>>>>>>> Cheers
>>>>>>>>>>> /Eike
>>>>>
>>>>
>>>
>>>


--

With Regards, Martin Taal

Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
Re: [CDO] reading/writting throughput performances [message #124561 is a reply to message #124535] Sun, 01 June 2008 12:40 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

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Hi Martin,

Ah, now with the new mapping I get a big step further!
As I said, Cedric's test code contained some bugs, too. IIRC a TCP
acceptor was created but the client uses a JVMConnector, and stuff like
this.
You could try to overcome the exception below by adding the following to
the server code somewhere:

| IPluginContainer.INSTANCE.getElement("org.eclipse.net4j.acceptors ", "jvm", "default");|



Better just use the attached zip because there may be other changes that
I don't remember in detail anymore.
Now I run into another exception:

Thread-4 [debug.signal] ================ Indicating
CommitTransactionIndication
Thread-4 [debug] Created
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
repository repo1
Thread-4 [debug] Created
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
repository repo1
Thread-4 [debug] Created
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
repository repo1
Thread-4 [debug.protocol] Reading 0 new packages
Thread-4 [debug.protocol] Reading 2 new objects
Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
Thread-4 [debug.model] Reading CDOID of type 0 (NULL)
Thread-4 [debug.revision] Reading revision: ID=oid1,
classRef=CDOClassRef(http://www.eclipse.org/emf/CDO/resource/1.0.0, 0),
className=CDOResource, version=1, created=0, revised=0, resource=oid1,
container=NULL, feature=0
Thread-4 [debug.revision] Read feature CDOFeature(ID=9, name=path,
type=STRING, referenceType=null): /res2
Thread-4 [debug.revision] Read feature CDOFeature(ID=2, name=contents,
type=OBJECT, referenceType=CDOClass(ID=0, name=CDOObject)): size=1
Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
Thread-4 [debug.revision] oid2
[ERROR] ClassRef unresolveable:
CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
java.lang.IllegalStateException: ClassRef unresolveable:
CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
at
org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionIm pl. <init>(CDORevisionImpl.java:116)
at
org.eclipse.emf.cdo.protocol.revision.CDORevisionUtil.read(C DORevisionUtil.java:48)
at
org.eclipse.emf.cdo.internal.server.protocol.CommitTransacti onIndication.indicating(CommitTransactionIndication.java:95)
at
org.eclipse.net4j.signal.IndicationWithResponse.execute(Indi cationWithResponse.java:46)
at org.eclipse.net4j.signal.Signal.runSync(Signal.java:143)
at org.eclipse.net4j.signal.Signal.run(Signal.java:124)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Threa dPoolExecutor.java:650)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoo lExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)

Cheers
/Eike



Martin Taal schrieb:
> Hi Eike, Cedric,
> I can't say to much about net4j.db versus net4j.db.hsqldb.
>
> You are correct that the hibernate.libraries plugin should have
> Eclipse-BuddyPolicy: dependent (or another way to use the classpath of
> the dependent plugins). Btw, I agree that registered is better as
> afaik dependent gets slow which larger plugin environments.
>
> The reason that cglib is used is because one of the class mappings in
> org.eclipse.emf.cdo.server.hibernate/mappings/meta.hbm/xml did not
> have the lazy="false" directive. I added this and now I get another
> exception (see below). So this 'solves' the problem. If you do a get
> latest of this file then I think this problem is 'overcome'.
>
> Overall I still do not see why it went wrong. As far as I can see the
> cglib library could not find the hibernate class, which is strange as
> they are in the same plugin??
> The cdo testcases don't have this problem and neither does Teneo.
>
> As it does not occur anymore we can ignore it for now (not very
> satisfactory but there are other things to do)... Unless someone else
> has an idea how to handle this ofcourse.
>
> gr. Martin
>
> java.lang.IllegalStateException: acceptor == null
> at
> org.eclipse.net4j.internal.jvm.JVMClientConnector.doBeforeAc tivate(JVMClientConnector.java:57)
>
> at
> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:56)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>
> at
> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>
> at
> org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:260)
>
> at
> org.eclipse.emf.internal.cdo.util.ChannelInjector.getConnect or(ChannelInjector.java:74)
>
> at
> org.eclipse.emf.internal.cdo.util.ChannelInjector.process(Ch annelInjector.java:41)
>
> at
> org.eclipse.net4j.internal.util.container.ManagedContainer.p ostProcessElement(ManagedContainer.java:407)
>
> at
> org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:259)
>
> at
> org.eclipse.cdo.bug.hibernate.HibernateServer.createSession( HibernateServer.java:93)
>
> at
> org.eclipse.cdo.bug.unit.LaunchServerTest.testStringValue(La unchServerTest.java:43)
>
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at junit.framework.TestCase.runTest(TestCase.java:164)
> at junit.framework.TestCase.runBare(TestCase.java:130)
> at junit.framework.TestResult$1.protect(TestResult.java:106)
> at junit.framework.TestResult.runProtected(TestResult.java:124)
> at junit.framework.TestResult.run(TestResult.java:109)
> at junit.framework.TestCase.run(TestCase.java:120)
> at junit.framework.TestSuite.runTest(TestSuite.java:230)
> at junit.framework.TestSuite.run(TestSuite.java:225)
> at
> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>
> at
> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>
> at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>
> at
> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>
> at
> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at
> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hod(EclipseAppContainer.java:547)
>
> at
> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>
> at
> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:106)
>
> at
> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:76)
>
> at
> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:362)
>
> at
> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:175)
>
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>
> at java.lang.reflect.Method.invoke(Method.java:585)
> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 564)
> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
> at org.eclipse.equinox.launcher.Main.run(Main.java:1251)
> at org.eclipse.equinox.launcher.Main.main(Main.java:1227)
>
>
>
> Eike Stepper wrote:
>> Hi,
>>
>> Here is a diagram of the dependencies of the relevant plugins (please
>> correct me if something is wrong).
>> The black arrows are ordinary downstream dependencies (Require-Bundle).
>> The red arrows are upstream dependencies (Eclipse-BuddyPolicy:
>> dependent).
>>
>>
>>
>> For research purposes I added code to the libraries plugin that tries
>> to reflectively load CDOFeatureImpl and that is not a problem!
>> It seems to me as if our problem is not class loading related because
>> the hibernate.jar should be able to see the needed classes.
>> I believe this is either a bug in Hibernate or our wrong usage of
>> Hibernate. I tend to believe the latter ;-)
>> I put a breakpoint in
>> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
>> EntityMetamodel)
>> to see how the tuplizers are created. I'm too unexperienced with
>> Hibernate to get a clue about what happens there...
>>
>> Btw. I'd prefer to see the application plugin depend on net4j.db
>> instead of net4j.db.hsqldb.
>> But it seems as if the BuddyPolicy in net4j.db is not "reexported" so
>> that the application can see the hsqldb.jar then ;-(
>> I posted a respective question to equinox...
>>
>> Cheers
>> /Eike
>>
>>
>> Eike Stepper schrieb:
>>> Hi guys,
>>>
>>> I can confirm, making these 3rd party libraries with their own
>>> classloading run in OSGi is a nightmare! I took me hours teach where
>>> the hsqldb driver is. On the way I came over different kinds of
>>> classloading related errors.
>>>
>>> First I removed all the jars from the test plugin (the one Cedric
>>> provided). They're already in the cdo.server.hibernate.libraries
>>> plugin which, in fact, needs the buddy policy set to dependent. I
>>> think this last change needs to be committed to CVS! Btw. I'd prefer
>>> to use *registered* buddies instead of making all dependent bundles
>>> visible.
>>>
>>> The test plugin then needs to provide the database driver. Therefore
>>> I added a dependency on the org.eclipse.net4j.db.hsqldb plugin.
>>>
>>> With this setup I can start the server without CNFE, NCDFE, CCI and
>>> the like. At this point I get the following exception, which seems
>>> the same as the one Cedric observed in the end:
>>>
>>> net.sf.cglib.core.CodeGenerationException:
>>> java.lang.reflect.InvocationTargetException-->null
>>> at
>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
>>>
>>> at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
>>> at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
>>> at
>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
>>>
>>> at
>>> org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
>>>
>>> at
>>> org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
>>>
>>> at
>>> org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
>>>
>>> at
>>> org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
>>>
>>> at
>>> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
>>>
>>> at
>>> org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
>>>
>>> at
>>> org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
>>>
>>> at
>>> org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
>>>
>>> at
>>> org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
>>>
>>> at
>>> org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
>>>
>>> at
>>> org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
>>>
>>> at
>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
>>>
>>> at
>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
>>>
>>> at
>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
>>>
>>> at
>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
>>>
>>> at
>>> org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
>>>
>>> at
>>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>
>>> at
>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>
>>> at
>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>
>>> at
>>> org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
>>>
>>> at
>>> org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
>>>
>>> at
>>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>
>>> at
>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>
>>> at
>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>
>>> at
>>> org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
>>>
>>> at
>>> org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
>>> at junit.framework.TestCase.runBare(TestCase.java:128)
>>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>>> at junit.framework.TestResult.run(TestResult.java:109)
>>> at junit.framework.TestCase.run(TestCase.java:120)
>>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>>> at junit.framework.TestSuite.run(TestSuite.java:225)
>>> at
>>> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>>
>>> at
>>> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>>
>>> at
>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>>
>>> at
>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>>
>>> at
>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>>
>>> at
>>> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>>
>>> at
>>> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>>
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at
>>> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
>>>
>>> at
>>> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>>
>>> at
>>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
>>>
>>> at
>>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
>>>
>>> at
>>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
>>>
>>> at
>>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
>>>
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
>>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>>> at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
>>> at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
>>> Caused by: java.lang.reflect.InvocationTargetException
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
>>> at
>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>
>>> ... 61 more
>>> Caused by: java.lang.NoClassDefFoundError:
>>> org/hibernate/proxy/HibernateProxy
>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>> ... 67 more
>>>
>>> I must admit that I'm still not sure about te fundamental interwork
>>> between Hibernate and the user defined meta model. It seems as if
>>> asm and cglib are somewhere in between but I have no idea why at
>>> all. I thought we have implemented a bunch of static Hibernate
>>> interfaces to make the CDORevision instances known to Hibernate.
>>> Please somebody explain why we need runtime byte code engineering?
>>> Is there some configuration missing to tell Hibernate to use our
>>> special tuplizers?
>>>
>>> I have changed several things in the code of the test plugin and
>>> since it's quite small now that the jars are removed, I attach my
>>> version of the zip here (including a JUnit Plugin launch config).
>>> And don't forget to update the cdo.server.hibernate.libraries plugin
>>> from CVS to get the new buddy policy!
>>>
>>> Cheers
>>> /Eike
>>>
>>> Martin Taal schrieb:
>>>> Hi Cédric,
>>>> I looked at it for many hours trying different things (using your
>>>> testcase) but I am kind of stuck with this (getting the same error
>>>> as you). The difference I can see with the way I run the
>>>> cdo.hibernate testcases (as a junit test) and how your testcase is
>>>> run (junit plugin test). This for sure means difference in class
>>>> loader behavior.
>>>>
>>>> Eike, do you have an idea? I am not sure how classloading works
>>>> when you start a cdo server in a plugin. Which plugins are then
>>>> available in the cdo server? The testcases can be downloaded from
>>>> the link below.
>>>>
>>>> gr. Martin
>>>>
>>>> Cédric Brun wrote:
>>>>> Thanks a lot ! I'm looking forward to your advices !
>>>>>
>>>>> Cédric
>>>>>
>>>>> Martin Taal wrote:
>>>>>
>>>>>> I am downloading your zip-file. I don't have time to look at it
>>>>>> right away
>>>>>> but I will do my best later this evening.
>>>>>>
>>>>>> gr. Martin
>>>>>>
>>>>>> Cédric Brun wrote:
>>>>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>>>>
>>>>>>> Here's a zipped project trying to launch an HibernateServer with
>>>>>>> a unit
>>>>>>> test adding elements.
>>>>>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>>>>> The
>>>>>>> libs I found are included in the same project, but I still have
>>>>>>> no luck
>>>>>>> and failling at :
>>>>>>>
>>>>>>> at
>>>>>>>
>>>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>>
>>>>>>> ... 62 more
>>>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>>>> org/hibernate/proxy/HibernateProxy
>>>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>>>> ... 68 more
>>>>>>>
>>>>>>> please note that the test project I provide really is a "quick
>>>>>>> and ugly"
>>>>>>> one ^^
>>>>>>>
>>>>>>>
>>>>>>> Cédric
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Martin Taal wrote:
>>>>>>>
>>>>>>>> Hmm, I can understand your headache. Classpath issues are the most
>>>>>>>> annoying errors...
>>>>>>>>
>>>>>>>> In your junit test source file, what happens when you enter the
>>>>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>>>>
>>>>>>>> What I also find slightly strange is that cglib is used in this
>>>>>>>> case
>>>>>>>> because normally cdo objects are not proxied using cglib. Can
>>>>>>>> you post
>>>>>>>> the generated mapping? How does your cdo initialization code
>>>>>>>> look like?
>>>>>>>>
>>>>>>>> gr. Martin
>>>>>>>>
>>>>>>>> Cédric Brun wrote:
>>>>>>>>> Hi Martin,
>>>>>>>>>
>>>>>>>>> and thanks for your quick answer ! what I did is the following :
>>>>>>>>>
>>>>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries
>>>>>>>>> bundle and
>>>>>>>>> added that :
>>>>>>>>>
>>>>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>>>>> lib/cglib-2.1.3.jar,
>>>>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>>>>> lib/dom4j.jar,
>>>>>>>>> lib/jta.jar
>>>>>>>>> lib/asm-3.0.jar
>>>>>>>>>
>>>>>>>>> and this directive :
>>>>>>>>>
>>>>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>>>>
>>>>>>>>> as stated in
>>>>>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Then I don't get the same error, now when I start my own
>>>>>>>>> plugin (JUnit
>>>>>>>>> plugin test) depending on
>>>>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>>>>
>>>>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>>>>> at
>>>>>>>>> net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>>>>> at
>>>>>>>>> net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>>>>> at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>>>>> at
>>>>>>>>>
>>>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>>>
>>>>>>>>> These jars are such a headache ! Do you know - by chance -
>>>>>>>>> what's
>>>>>>>>> going on ?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Cédric
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Martin Taal wrote:
>>>>>>>>>
>>>>>>>>>> Hi Cédric,
>>>>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>>>>> can't find
>>>>>>>>>> the class. A common cause is that the hibernate jar files are
>>>>>>>>>> located
>>>>>>>>>> in a separate plugin which can not reach the classes in other
>>>>>>>>>> plugins.
>>>>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>>>>> dependent then this can help.
>>>>>>>>>>
>>>>>>>>>> gr. Martin
>>>>>>>>>>
>>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>>> Hi Simon and Eike,
>>>>>>>>>>>
>>>>>>>>>>> thanks for your feedback, now I know what I could expect in
>>>>>>>>>>> using
>>>>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>>>>> store and
>>>>>>>>>>> see if it is scaling in a better way.
>>>>>>>>>>>
>>>>>>>>>>> You gave me many pointers to explain the performances issues
>>>>>>>>>>> but in
>>>>>>>>>>> fact it seems that the SQL execution is taking so much time
>>>>>>>>>>> (not
>>>>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>>>>
>>>>>>>>>>> So I'm installing the hibernate store retrieving all the
>>>>>>>>>>> source code
>>>>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added
>>>>>>>>>>> many jars
>>>>>>>>>>> and everything gets compiled but most of the tests are
>>>>>>>>>>> failling with
>>>>>>>>>>> "
>>>>>>>>>>>
>>>>>>>>>>> "
>>>>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>>>>
>>>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>
>>>>>>>>>>> at table: cdo_features, for columns:
>>>>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>>>>
>>>>>>>>>>> any hint ?
>>>>>>>>>>>
>>>>>>>>>>> Cédric
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Simon McDuff wrote:
>>>>>>>>>>>
>>>>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>>>>
>>>>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>>>>> collections that
>>>>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>>>>
>>>>>>>>>>>> Model:
>>>>>>>>>>>>
>>>>>>>>>>>> ClassB
>>>>>>>>>>>> {
>>>>>>>>>>>> int foo1;
>>>>>>>>>>>> List childrens1;
>>>>>>>>>>>> List childrens2;
>>>>>>>>>>>> List childrens3;
>>>>>>>>>>>> };
>>>>>>>>>>>>
>>>>>>>>>>>> Code:
>>>>>>>>>>>>
>>>>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>>>>
>>>>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>>>>> items in
>>>>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem we
>>>>>>>>>>>> had.. is
>>>>>>>>>>>> we do not know if we want to use it. SO better not to
>>>>>>>>>>>> download them.
>>>>>>>>>>>>
>>>>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>>>>> download any
>>>>>>>>>>>> objects from collection. I'm working at the moment to put
>>>>>>>>>>>> in place
>>>>>>>>>>>> all feature we used in the current CDO. That one will be
>>>>>>>>>>>> part of
>>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To begin
>>>>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0 even if
>>>>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>>>>
>>>>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>>>>> Worst case :
>>>>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that contains
>>>>>>>>>>>> the
>>>>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>>>>
>>>>>>>>>>>> Best case
>>>>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the
>>>>>>>>>>>> case of
>>>>>>>>>>>> the filesystem)
>>>>>>>>>>>>
>>>>>>>>>>>> (These statistics always fetch objects from server to
>>>>>>>>>>>> client. The
>>>>>>>>>>>> cache client isn't used)
>>>>>>>>>>>>
>>>>>>>>>>>> We have another optimization one with SmartReadAhead but
>>>>>>>>>>>> for now
>>>>>>>>>>>> only work
>>>>>>>>>>>> for UI client. (for now) This is something we will
>>>>>>>>>>>> integrate as
>>>>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>>>>
>>>>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>>>>> without CDO.
>>>>>>>>>>>> I compare
>>>>>>>>>>>>
>>>>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than Hibernate.
>>>>>>>>>>>>
>>>>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>>>>
>>>>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>>>>> Derby)!!
>>>>>>>>>>>> :-)
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Another comments about insertion.
>>>>>>>>>>>>
>>>>>>>>>>>> We found another problem when we insert data(DOn't know if
>>>>>>>>>>>> it is
>>>>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>>>>> each time
>>>>>>>>>>>> we insert one element, it needs to fetch all the collection
>>>>>>>>>>>> to see
>>>>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>>>>> consuming.
>>>>>>>>>>>> In our case we are not going through this stage to persist our
>>>>>>>>>>>> objects... but the objects are not accessible through that
>>>>>>>>>>>> list.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> If speed is an issue for you!! We (You included :-)) can
>>>>>>>>>>>> optimize
>>>>>>>>>>>> it. What I like is Eike did a really good job doing that
>>>>>>>>>>>> framwork
>>>>>>>>>>>> and optimizations are easy to add. Also you can change your
>>>>>>>>>>>> back-end
>>>>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Simon
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le
>>>>>>>>>>>> message de
>>>>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>>>>
>>>>>>>>>>>> That sounds interesting!
>>>>>>>>>>>> Comments inline...
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>>>>> Hi Eike,
>>>>>>>>>>>>
>>>>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>>>>> unit-tests measuring read/write throughput when I use CDO
>>>>>>>>>>>> (RC2).
>>>>>>>>>>>>
>>>>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple
>>>>>>>>>>>> one - 1
>>>>>>>>>>>> Classifier/3 Features)
>>>>>>>>>>>>
>>>>>>>>>>>> The test is a "quick and dirty" one so please do not take
>>>>>>>>>>>> these
>>>>>>>>>>>> figures too seriously, I would just like to have your input
>>>>>>>>>>>> about
>>>>>>>>>>>> the "order of magnitude" I should expect or settings affecting
>>>>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>>>>> acceptor but
>>>>>>>>>>>> the performances are quite similar though JVM is a bit faster.
>>>>>>>>>>>> Looks like a sign that the NIO socket channels are
>>>>>>>>>>>> efficient ,-)
>>>>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> * First case : building a small model (10000 elements) with
>>>>>>>>>>>> the
>>>>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>>>>> commiting change on every add I get a 2 objects per second
>>>>>>>>>>>> rate.
>>>>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per
>>>>>>>>>>>> second
>>>>>>>>>>>> rate.
>>>>>>>>>>>> Seems to be consistent with the fact that only for
>>>>>>>>>>>> commits there
>>>>>>>>>>>> is remote traffic. And the backend transaction management is
>>>>>>>>>>>> another overhead. So the impact of the number objects/commit
>>>>>>>>>>>> starts with bigger transactions.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> browsing the just commited elements opening a new
>>>>>>>>>>>> transaction and
>>>>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>>>>> objets/sec rate
>>>>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>>>>> All views and transactions of a single session share (and
>>>>>>>>>>>> cache)
>>>>>>>>>>>> their object state. Otherwise I'd expect much smaller
>>>>>>>>>>>> values.
>>>>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed)
>>>>>>>>>>>> reached
>>>>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>>>>> (which you
>>>>>>>>>>>> used) is not that optimized.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>>>>> complex metamodel. It contains 700 000 elements. The
>>>>>>>>>>>> creation went
>>>>>>>>>>>> pretty nicely (I did not measured it exactly as it was
>>>>>>>>>>>> launched
>>>>>>>>>>>> during a night, but it seems I got around 100 objects/sec
>>>>>>>>>>>> rate in
>>>>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>>>>> Sounds not too bad.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Once the model is built the derby database is 222 MB (which
>>>>>>>>>>>> - I
>>>>>>>>>>>> heard - is not so big for derby).
>>>>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>>>>> To be honest, I'm really no database expert (although I
>>>>>>>>>>>> can write
>>>>>>>>>>>> simple SQL statements).
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Retrieving the distant resource and calling eAllContents()
>>>>>>>>>>>> on it, I
>>>>>>>>>>>> get a 50 Objects/sec rate at best, which mean my
>>>>>>>>>>>> eAllContents() call
>>>>>>>>>>>> would take 4 hours !
>>>>>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>>>>>> (iteration order and so). There are several CDO features
>>>>>>>>>>>> that can
>>>>>>>>>>>> have a major impact on load rates!
>>>>>>>>>>>>
>>>>>>>>>>>> - Collections (xrefs and containment) can be loaded
>>>>>>>>>>>> lazily. I
>>>>>>>>>>>> don't mean the target objects, which are lazy by default
>>>>>>>>>>>> anyway,
>>>>>>>>>>>> but even the target IDs that are in the collections. We
>>>>>>>>>>>> call that
>>>>>>>>>>>> "reference chunking" (but search for a better name is
>>>>>>>>>>>> ongoing).
>>>>>>>>>>>>
>>>>>>>>>>>> public interface CDOSession extends
>>>>>>>>>>>> CDOProtocolSession,
>>>>>>>>>>>> IContainer<CDOView>
>>>>>>>>>>>> {
>>>>>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>>>>>
>>>>>>>>>>>> public void setReferenceChunkSize(int
>>>>>>>>>>>> referenceChunkSize);
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> - Loading collection elements (target objects) can be
>>>>>>>>>>>> batched (the
>>>>>>>>>>>> current name is even worse)
>>>>>>>>>>>>
>>>>>>>>>>>> public interface CDOView extends CDOProtocolView,
>>>>>>>>>>>> INotifier
>>>>>>>>>>>> {
>>>>>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>>>>>
>>>>>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> - One of the most sophisticated feature is automatic
>>>>>>>>>>>> model usage
>>>>>>>>>>>> analyzation. The result are fetch rules that are sent to the
>>>>>>>>>>>> server. When later objects are loaded from the server, it
>>>>>>>>>>>> can
>>>>>>>>>>>> answer with additional objects that are likely to be
>>>>>>>>>>>> needed by the
>>>>>>>>>>>> client in the near future.
>>>>>>>>>>>>
>>>>>>>>>>>> public class CDOViewImpl extends
>>>>>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier
>>>>>>>>>>>> implements
>>>>>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>>>>>> {
>>>>>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>>>>>> {
>>>>>>>>>>>> return featureAnalyzer;
>>>>>>>>>>>> }
>>>>>>>>>>>>
>>>>>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>>>>>> featureAnalyzer)
>>>>>>>>>>>> {
>>>>>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>>>>>> }
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> - There's a SmartReadAheadThread (if you're curious,
>>>>>>>>>>>> please ask
>>>>>>>>>>>> Simon). - Caches can be configured
>>>>>>>>>>>> - ...
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Known issues of the DBStore:
>>>>>>>>>>>> - When in auditing mode updates are always written as
>>>>>>>>>>>> complete
>>>>>>>>>>>> inserts (by design) - When configuring toManyReferences
>>>>>>>>>>>> to a value
>>>>>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented
>>>>>>>>>>>> yet) it
>>>>>>>>>>>> is very slow. - No (few) prepared statements are used (see
>>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214487) -
>>>>>>>>>>>> Maybe
>>>>>>>>>>>> others...
>>>>>>>>>>>>
>>>>>>>>>>>> Please note that the DBStore was not written by me to
>>>>>>>>>>>> compete with
>>>>>>>>>>>> Hibernate in terms of performance or mapping
>>>>>>>>>>>> capabilities. Now
>>>>>>>>>>>> that Martin and I, well in the end mostly Martin, provide a
>>>>>>>>>>>> HibernateStore and this HibernateStore gets more and more
>>>>>>>>>>>> features
>>>>>>>>>>>> I expect that there will be a trend away from the DBStore.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> This is probably linked to the way the mapping to db is
>>>>>>>>>>>> done, here's
>>>>>>>>>>>> the config I used (came from CDO-server example if I recall
>>>>>>>>>>>> correctly).
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> <repository name="repo1">
>>>>>>>>>>>> <property name="overrideUUID"
>>>>>>>>>>>> value="1ff5d226-b1f0-40fb-aba2-0c31b38c764f"/>
>>>>>>>>>>>> <property name="supportingAudits"
>>>>>>>>>>>> value="true"/>
>>>>>>>>>>>> <property name="verifyingRevisions"
>>>>>>>>>>>> value="false"/>
>>>>>>>>>>>> <property name="currentLRUCapacity"
>>>>>>>>>>>> value="10000"/>
>>>>>>>>>>>> I guess this one could be larger.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> <property name="revisedLRUCapacity"
>>>>>>>>>>>> value="100"/>
>>>>>>>>>>>> <store type="db">
>>>>>>>>>>>> <!-- type: horizontal | vertical |
>>>>>>>>>>>> <any
>>>>>>>>>>>> user-contributed type> -->
>>>>>>>>>>>> <mappingStrategy
>>>>>>>>>>>> type="horizontal">
>>>>>>>>>>>> <!-- ONE_TABLE_PER_REFERENCE |
>>>>>>>>>>>> ONE_TABLE_PER_CLASS |
>>>>>>>>>>>> ONE_TABLE_PER_PACKAGE | ONE_TABLE_PER_REPOSITORY |
>>>>>>>>>>>> LIKE_ATTRIBUTES
>>>>>>>>>>>> -->
>>>>>>>>>>>> <property
>>>>>>>>>>>> name="toManyReferences"
>>>>>>>>>>>>
>>>>>>>>>>>> value="ONE_TABLE_PER_REFERENCE"/>
>>>>>>>>>>>>
>>>>>>>>>>>> <!-- LIKE_ATTRIBUTES |
>>>>>>>>>>>> LIKE_TO_MANY_REFERENCES -->
>>>>>>>>>>>> <property
>>>>>>>>>>>> name="toOneReferences"
>>>>>>>>>>>> value="LIKE_ATTRIBUTES"/>
>>>>>>>>>>>>
>>>>>>>>>>>> <!-- MODEL | STRATEGY -->
>>>>>>>>>>>> <property
>>>>>>>>>>>&g
Re: [CDO] reading/writting throughput performances (SUCCESS) [message #124736 is a reply to message #124561] Sun, 01 June 2008 13:05 Go to previous messageGo to next message
Eclipse UserFriend
Originally posted by: stepper.sympedia.de

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Martin,

In the console log snippet below, please notice that it is the first
commit transaction signal and that there are no new packages contained.
This is caused by the client (test case) that didn't register the used
package with the client session before using it. The following snippet
uses the new automatic registry:

| *private *CDOSession createSession()
{
IConnector connector = (IConnector)IPluginContainer.INSTANCE.getElement("org.eclipse.net4j.connectors ", "jvm", "default");
System.out.println(connector);

CDOSessionConfiguration configuration = CDOUtil.createSessionConfiguration();
configuration.setConnector(connector);
configuration.setRepositoryName(REPO_NAME);
configuration.setDemandPopulatingPackageRegistry();
*return *configuration.openSession();
}|


Now the test cases pass properly!!!
Please see the attached log file.

Cheers
/Eike



Eike Stepper schrieb:
> Hi Martin,
>
> Ah, now with the new mapping I get a big step further!
> As I said, Cedric's test code contained some bugs, too. IIRC a TCP
> acceptor was created but the client uses a JVMConnector, and stuff
> like this.
> You could try to overcome the exception below by adding the following
> to the server code somewhere:
>
> | IPluginContainer.INSTANCE.getElement("org.eclipse.net4j.acceptors ", "jvm", "default");|
>
>
>
> Better just use the attached zip because there may be other changes
> that I don't remember in detail anymore.
> Now I run into another exception:
>
> Thread-4 [debug.signal] ================ Indicating
> CommitTransactionIndication
> Thread-4 [debug] Created
> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
> repository repo1
> Thread-4 [debug] Created
> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
> repository repo1
> Thread-4 [debug] Created
> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
> repository repo1
> Thread-4 [debug.protocol] Reading 0 new packages
> Thread-4 [debug.protocol] Reading 2 new objects
> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
> Thread-4 [debug.model] Reading CDOID of type 0 (NULL)
> Thread-4 [debug.revision] Reading revision: ID=oid1,
> classRef=CDOClassRef(http://www.eclipse.org/emf/CDO/resource/1.0.0,
> 0), className=CDOResource, version=1, created=0, revised=0,
> resource=oid1, container=NULL, feature=0
> Thread-4 [debug.revision] Read feature CDOFeature(ID=9, name=path,
> type=STRING, referenceType=null): /res2
> Thread-4 [debug.revision] Read feature CDOFeature(ID=2, name=contents,
> type=OBJECT, referenceType=CDOClass(ID=0, name=CDOObject)): size=1
> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
> Thread-4 [debug.revision] oid2
> [ERROR] ClassRef unresolveable:
> CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
> java.lang.IllegalStateException: ClassRef unresolveable:
> CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
> at
> org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionIm pl. <init>(CDORevisionImpl.java:116)
> at
> org.eclipse.emf.cdo.protocol.revision.CDORevisionUtil.read(C DORevisionUtil.java:48)
> at
> org.eclipse.emf.cdo.internal.server.protocol.CommitTransacti onIndication.indicating(CommitTransactionIndication.java:95)
> at
> org.eclipse.net4j.signal.IndicationWithResponse.execute(Indi cationWithResponse.java:46)
> at org.eclipse.net4j.signal.Signal.runSync(Signal.java:143)
> at org.eclipse.net4j.signal.Signal.run(Signal.java:124)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Threa dPoolExecutor.java:650)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoo lExecutor.java:675)
> at java.lang.Thread.run(Thread.java:595)
>
> Cheers
> /Eike
>
>
>
> Martin Taal schrieb:
>> Hi Eike, Cedric,
>> I can't say to much about net4j.db versus net4j.db.hsqldb.
>>
>> You are correct that the hibernate.libraries plugin should have
>> Eclipse-BuddyPolicy: dependent (or another way to use the classpath
>> of the dependent plugins). Btw, I agree that registered is better as
>> afaik dependent gets slow which larger plugin environments.
>>
>> The reason that cglib is used is because one of the class mappings in
>> org.eclipse.emf.cdo.server.hibernate/mappings/meta.hbm/xml did not
>> have the lazy="false" directive. I added this and now I get another
>> exception (see below). So this 'solves' the problem. If you do a get
>> latest of this file then I think this problem is 'overcome'.
>>
>> Overall I still do not see why it went wrong. As far as I can see the
>> cglib library could not find the hibernate class, which is strange as
>> they are in the same plugin??
>> The cdo testcases don't have this problem and neither does Teneo.
>>
>> As it does not occur anymore we can ignore it for now (not very
>> satisfactory but there are other things to do)... Unless someone else
>> has an idea how to handle this ofcourse.
>>
>> gr. Martin
>>
>> java.lang.IllegalStateException: acceptor == null
>> at
>> org.eclipse.net4j.internal.jvm.JVMClientConnector.doBeforeAc tivate(JVMClientConnector.java:57)
>>
>> at
>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:56)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>
>> at
>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>
>> at
>> org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:260)
>>
>> at
>> org.eclipse.emf.internal.cdo.util.ChannelInjector.getConnect or(ChannelInjector.java:74)
>>
>> at
>> org.eclipse.emf.internal.cdo.util.ChannelInjector.process(Ch annelInjector.java:41)
>>
>> at
>> org.eclipse.net4j.internal.util.container.ManagedContainer.p ostProcessElement(ManagedContainer.java:407)
>>
>> at
>> org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:259)
>>
>> at
>> org.eclipse.cdo.bug.hibernate.HibernateServer.createSession( HibernateServer.java:93)
>>
>> at
>> org.eclipse.cdo.bug.unit.LaunchServerTest.testStringValue(La unchServerTest.java:43)
>>
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at junit.framework.TestCase.runTest(TestCase.java:164)
>> at junit.framework.TestCase.runBare(TestCase.java:130)
>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>> at junit.framework.TestResult.run(TestResult.java:109)
>> at junit.framework.TestCase.run(TestCase.java:120)
>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>> at junit.framework.TestSuite.run(TestSuite.java:225)
>> at
>> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>
>> at
>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>
>> at
>> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>
>> at
>> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at
>> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hod(EclipseAppContainer.java:547)
>>
>> at
>> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>
>> at
>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:106)
>>
>> at
>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:76)
>>
>> at
>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:362)
>>
>> at
>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:175)
>>
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>
>> at java.lang.reflect.Method.invoke(Method.java:585)
>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 564)
>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>> at org.eclipse.equinox.launcher.Main.run(Main.java:1251)
>> at org.eclipse.equinox.launcher.Main.main(Main.java:1227)
>>
>>
>>
>> Eike Stepper wrote:
>>> Hi,
>>>
>>> Here is a diagram of the dependencies of the relevant plugins
>>> (please correct me if something is wrong).
>>> The black arrows are ordinary downstream dependencies (Require-Bundle).
>>> The red arrows are upstream dependencies (Eclipse-BuddyPolicy:
>>> dependent).
>>>
>>>
>>>
>>> For research purposes I added code to the libraries plugin that
>>> tries to reflectively load CDOFeatureImpl and that is not a problem!
>>> It seems to me as if our problem is not class loading related
>>> because the hibernate.jar should be able to see the needed classes.
>>> I believe this is either a bug in Hibernate or our wrong usage of
>>> Hibernate. I tend to believe the latter ;-)
>>> I put a breakpoint in
>>> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
>>> EntityMetamodel)
>>> to see how the tuplizers are created. I'm too unexperienced with
>>> Hibernate to get a clue about what happens there...
>>>
>>> Btw. I'd prefer to see the application plugin depend on net4j.db
>>> instead of net4j.db.hsqldb.
>>> But it seems as if the BuddyPolicy in net4j.db is not "reexported"
>>> so that the application can see the hsqldb.jar then ;-(
>>> I posted a respective question to equinox...
>>>
>>> Cheers
>>> /Eike
>>>
>>>
>>> Eike Stepper schrieb:
>>>> Hi guys,
>>>>
>>>> I can confirm, making these 3rd party libraries with their own
>>>> classloading run in OSGi is a nightmare! I took me hours teach
>>>> where the hsqldb driver is. On the way I came over different kinds
>>>> of classloading related errors.
>>>>
>>>> First I removed all the jars from the test plugin (the one Cedric
>>>> provided). They're already in the cdo.server.hibernate.libraries
>>>> plugin which, in fact, needs the buddy policy set to dependent. I
>>>> think this last change needs to be committed to CVS! Btw. I'd
>>>> prefer to use *registered* buddies instead of making all dependent
>>>> bundles visible.
>>>>
>>>> The test plugin then needs to provide the database driver.
>>>> Therefore I added a dependency on the org.eclipse.net4j.db.hsqldb
>>>> plugin.
>>>>
>>>> With this setup I can start the server without CNFE, NCDFE, CCI and
>>>> the like. At this point I get the following exception, which seems
>>>> the same as the one Cedric observed in the end:
>>>>
>>>> net.sf.cglib.core.CodeGenerationException:
>>>> java.lang.reflect.InvocationTargetException-->null
>>>> at
>>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
>>>>
>>>> at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
>>>> at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
>>>> at
>>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
>>>>
>>>> at
>>>> org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
>>>>
>>>> at
>>>> org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
>>>>
>>>> at
>>>> org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
>>>>
>>>> at
>>>> org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
>>>>
>>>> at
>>>> org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
>>>>
>>>> at
>>>> org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
>>>>
>>>> at
>>>> org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
>>>>
>>>> at
>>>> org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
>>>>
>>>> at
>>>> org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
>>>>
>>>> at
>>>> org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
>>>>
>>>> at
>>>> org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
>>>>
>>>> at
>>>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>>
>>>> at
>>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>>
>>>> at
>>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
>>>>
>>>> at
>>>> org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>>
>>>> at
>>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>>
>>>> at
>>>> org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>>
>>>> at
>>>> org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
>>>>
>>>> at
>>>> org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
>>>> at junit.framework.TestCase.runBare(TestCase.java:128)
>>>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>>>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>>>> at junit.framework.TestResult.run(TestResult.java:109)
>>>> at junit.framework.TestCase.run(TestCase.java:120)
>>>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>>>> at junit.framework.TestSuite.run(TestSuite.java:225)
>>>> at
>>>> org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>>>
>>>> at
>>>> org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>>>
>>>> at
>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>>>
>>>> at
>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>>>
>>>> at
>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>>>
>>>> at
>>>> org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>>>
>>>> at
>>>> org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>>>
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>> at
>>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>
>>>> at
>>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>
>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>> at
>>>> org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
>>>>
>>>> at
>>>> org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>>>
>>>> at
>>>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
>>>>
>>>> at
>>>> org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
>>>>
>>>> at
>>>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
>>>>
>>>> at
>>>> org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
>>>>
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>> at
>>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>
>>>> at
>>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>
>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
>>>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>>>> at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
>>>> at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
>>>> Caused by: java.lang.reflect.InvocationTargetException
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>> at
>>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>
>>>> at
>>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>
>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>> at
>>>> net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
>>>> at
>>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>
>>>> ... 61 more
>>>> Caused by: java.lang.NoClassDefFoundError:
>>>> org/hibernate/proxy/HibernateProxy
>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>> ... 67 more
>>>>
>>>> I must admit that I'm still not sure about te fundamental interwork
>>>> between Hibernate and the user defined meta model. It seems as if
>>>> asm and cglib are somewhere in between but I have no idea why at
>>>> all. I thought we have implemented a bunch of static Hibernate
>>>> interfaces to make the CDORevision instances known to Hibernate.
>>>> Please somebody explain why we need runtime byte code engineering?
>>>> Is there some configuration missing to tell Hibernate to use our
>>>> special tuplizers?
>>>>
>>>> I have changed several things in the code of the test plugin and
>>>> since it's quite small now that the jars are removed, I attach my
>>>> version of the zip here (including a JUnit Plugin launch config).
>>>> And don't forget to update the cdo.server.hibernate.libraries
>>>> plugin from CVS to get the new buddy policy!
>>>>
>>>> Cheers
>>>> /Eike
>>>>
>>>> Martin Taal schrieb:
>>>>> Hi Cédric,
>>>>> I looked at it for many hours trying different things (using your
>>>>> testcase) but I am kind of stuck with this (getting the same error
>>>>> as you). The difference I can see with the way I run the
>>>>> cdo.hibernate testcases (as a junit test) and how your testcase is
>>>>> run (junit plugin test). This for sure means difference in class
>>>>> loader behavior.
>>>>>
>>>>> Eike, do you have an idea? I am not sure how classloading works
>>>>> when you start a cdo server in a plugin. Which plugins are then
>>>>> available in the cdo server? The testcases can be downloaded from
>>>>> the link below.
>>>>>
>>>>> gr. Martin
>>>>>
>>>>> Cédric Brun wrote:
>>>>>> Thanks a lot ! I'm looking forward to your advices !
>>>>>>
>>>>>> Cédric
>>>>>>
>>>>>> Martin Taal wrote:
>>>>>>
>>>>>>> I am downloading your zip-file. I don't have time to look at it
>>>>>>> right away
>>>>>>> but I will do my best later this evening.
>>>>>>>
>>>>>>> gr. Martin
>>>>>>>
>>>>>>> Cédric Brun wrote:
>>>>>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>>>>>
>>>>>>>> Here's a zipped project trying to launch an HibernateServer
>>>>>>>> with a unit
>>>>>>>> test adding elements.
>>>>>>>> ( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>>>>>> The
>>>>>>>> libs I found are included in the same project, but I still have
>>>>>>>> no luck
>>>>>>>> and failling at :
>>>>>>>>
>>>>>>>> at
>>>>>>>>
>>>>>> net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>>>
>>>>>>>> ... 62 more
>>>>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>>>>> org/hibernate/proxy/HibernateProxy
>>>>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>>>>> ... 68 more
>>>>>>>>
>>>>>>>> please note that the test project I provide really is a "quick
>>>>>>>> and ugly"
>>>>>>>> one ^^
>>>>>>>>
>>>>>>>>
>>>>>>>> Cédric
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Martin Taal wrote:
>>>>>>>>
>>>>>>>>> Hmm, I can understand your headache. Classpath issues are the
>>>>>>>>> most
>>>>>>>>> annoying errors...
>>>>>>>>>
>>>>>>>>> In your junit test source file, what happens when you enter the
>>>>>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>>>>>
>>>>>>>>> What I also find slightly strange is that cglib is used in
>>>>>>>>> this case
>>>>>>>>> because normally cdo objects are not proxied using cglib. Can
>>>>>>>>> you post
>>>>>>>>> the generated mapping? How does your cdo initialization code
>>>>>>>>> look like?
>>>>>>>>>
>>>>>>>>> gr. Martin
>>>>>>>>>
>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>> Hi Martin,
>>>>>>>>>>
>>>>>>>>>> and thanks for your quick answer ! what I did is the
>>>>>>>>>> following :
>>>>>>>>>>
>>>>>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries
>>>>>>>>>> bundle and
>>>>>>>>>> added that :
>>>>>>>>>>
>>>>>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>>>>>> lib/cglib-2.1.3.jar,
>>>>>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>>>>>> lib/dom4j.jar,
>>>>>>>>>> lib/jta.jar
>>>>>>>>>> lib/asm-3.0.jar
>>>>>>>>>>
>>>>>>>>>> and this directive :
>>>>>>>>>>
>>>>>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>>>>>
>>>>>>>>>> as stated in
>>>>>>>>>> http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Then I don't get the same error, now when I start my own
>>>>>>>>>> plugin (JUnit
>>>>>>>>>> plugin test) depending on
>>>>>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>>>>>
>>>>>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>>>>>> at
>>>>>>>>>> net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>>>>>> at
>>>>>>>>>> net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>>>>>> at
>>>>>>>>>> net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>>>>>> at
>>>>>>>>>>
>>>>>> org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>>>>
>>>>>>>>>> These jars are such a headache ! Do you know - by chance -
>>>>>>>>>> what's
>>>>>>>>>> going on ?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Cédric
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Martin Taal wrote:
>>>>>>>>>>
>>>>>>>>>>> Hi Cédric,
>>>>>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>>>>>> can't find
>>>>>>>>>>> the class. A common cause is that the hibernate jar files
>>>>>>>>>>> are located
>>>>>>>>>>> in a separate plugin which can not reach the classes in
>>>>>>>>>>> other plugins.
>>>>>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>>>>>> dependent then this can help.
>>>>>>>>>>>
>>>>>>>>>>> gr. Martin
>>>>>>>>>>>
>>>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>>>> Hi Simon and Eike,
>>>>>>>>>>>>
>>>>>>>>>>>> thanks for your feedback, now I know what I could expect in
>>>>>>>>>>>> using
>>>>>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>>>>>> store and
>>>>>>>>>>>> see if it is scaling in a better way.
>>>>>>>>>>>>
>>>>>>>>>>>> You gave me many pointers to explain the performances
>>>>>>>>>>>> issues but in
>>>>>>>>>>>> fact it seems that the SQL execution is taking so much time
>>>>>>>>>>>> (not
>>>>>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>>>>>
>>>>>>>>>>>> So I'm installing the hibernate store retrieving all the
>>>>>>>>>>>> source code
>>>>>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added
>>>>>>>>>>>> many jars
>>>>>>>>>>>> and everything gets compiled but most of the tests are
>>>>>>>>>>>> failling with
>>>>>>>>>>>> "
>>>>>>>>>>>>
>>>>>>>>>>>> "
>>>>>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>>>>>
>>>>>> org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>
>>>>>>>>>>>> at table: cdo_features, for columns:
>>>>>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>>>>>
>>>>>>>>>>>> any hint ?
>>>>>>>>>>>>
>>>>>>>>>>>> Cédric
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Simon McDuff wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>>>>>
>>>>>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>>>>>> collections that
>>>>>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Model:
>>>>>>>>>>>>>
>>>>>>>>>>>>> ClassB
>>>>>>>>>>>>> {
>>>>>>>>>>>>> int foo1;
>>>>>>>>>>>>> List childrens1;
>>>>>>>>>>>>> List childrens2;
>>>>>>>>>>>>> List childrens3;
>>>>>>>>>>>>> };
>>>>>>>>>>>>>
>>>>>>>>>>>>> Code:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>>>>>
>>>>>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>>>>>> items in
>>>>>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem
>>>>>>>>>>>>> we had.. is
>>>>>>>>>>>>> we do not know if we want to use it. SO better not to
>>>>>>>>>>>>> download them.
>>>>>>>>>>>>>
>>>>>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>>>>>> download any
>>>>>>>>>>>>> objects from collection. I'm working at the moment to put
>>>>>>>>>>>>> in place
>>>>>>>>>>>>> all feature we used in the current CDO. That one will be
>>>>>>>>>>>>> part of
>>>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To
>>>>>>>>>>>>> begin
>>>>>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0
>>>>>>>>>>>>> even if
>>>>>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>>>>>
>>>>>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>>>>>> Worst case :
>>>>>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that
>>>>>>>>>>>>> contains the
>>>>>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>>>>>
>>>>>>>>>>>>> Best case
>>>>>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the
>>>>>>>>>>>>> case of
>>>>>>>>>>>>> the filesystem)
>>>>>>>>>>>>>
>>>>>>>>>>>>> (These statistics always fetch objects from server to
>>>>>>>>>>>>> client. The
>>>>>>>>>>>>> cache client isn't used)
>>>>>>>>>>>>>
>>>>>>>>>>>>> We have another optimization one with SmartReadAhead but
>>>>>>>>>>>>> for now
>>>>>>>>>>>>> only work
>>>>>>>>>>>>> for UI client. (for now) This is something we will
>>>>>>>>>>>>> integrate as
>>>>>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>>>>>> without CDO.
>>>>>>>>>>>>> I compare
>>>>>>>>>>>>>
>>>>>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than
>>>>>>>>>>>>> Hibernate.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>>>>>
>>>>>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>>>>>> Derby)!!
>>>>>>>>>>>>> :-)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Another comments about insertion.
>>>>>>>>>>>>>
>>>>>>>>>>>>> We found another problem when we insert data(DOn't know if
>>>>>>>>>>>>> it is
>>>>>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>>>>>> each time
>>>>>>>>>>>>> we insert one element, it needs to fetch all the
>>>>>>>>>>>>> collection to see
>>>>>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>>>>>> consuming.
>>>>>>>>>>>>> In our case we are not going through this stage to persist
>>>>>>>>>>>>> our
>>>>>>>>>>>>> objects... but the objects are not accessible through that
>>>>>>>>>>>>> list.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> If speed is an issue for you!! We (You included :-)) can
>>>>>>>>>>>>> optimize
>>>>>>>>>>>>> it. What I like is Eike did a really good job doing that
>>>>>>>>>>>>> framwork
>>>>>>>>>>>>> and optimizations are easy to add. Also you can change
>>>>>>>>>>>>> your back-end
>>>>>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Simon
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le
>>>>>>>>>>>>> message de
>>>>>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>>>>>
>>>>>>>>>>>>> That sounds interesting!
>>>>>>>>>>>>> Comments inline...
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>>>>>> Hi Eike,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>>>>>> unit-tests measuring read/write throughput when I use CDO
>>>>>>>>>>>>> (RC2).
>>>>>>>>>>>>>
>>>>>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple
>>>>>>>>>>>>> one - 1
>>>>>>>>>>>>> Classifier/3 Features)
>>>>>>>>>>>>>
>>>>>>>>>>>>> The test is a "quick and dirty" one so please do not take
>>>>>>>>>>>>> these
>>>>>>>>>>>>> figures too seriously, I would just like to have your
>>>>>>>>>>>>> input about
>>>>>>>>>>>>> the "order of magnitude" I should expect or settings
>>>>>>>>>>>>> affecting
>>>>>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>>>>>> acceptor but
>>>>>>>>>>>>> the performances are quite similar though JVM is a bit
>>>>>>>>>>>>> faster.
>>>>>>>>>>>>> Looks like a sign that the NIO socket channels are
>>>>>>>>>>>>> efficient ,-)
>>>>>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> * First case : building a small model (10000 elements)
>>>>>>>>>>>>> with the
>>>>>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>>>>>> commiting change on every add I get a 2 objects per second
>>>>>>>>>>>>> rate.
>>>>>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per
>>>>>>>>>>>>> second
>>>>>>>>>>>>> rate.
>>>>>>>>>>>>> Seems to be consistent with the fact that only for
>>>>>>>>>>>>> commits there
>>>>>>>>>>>>> is remote traffic. And the backend transaction
>>>>>>>>>>>>> management is
>>>>>>>>>>>>> another overhead. So the impact of the number
>>>>>>>>>>>>> objects/commit
>>>>>>>>>>>>> starts with bigger transactions.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> browsing the just commited elements opening a new
>>>>>>>>>>>>> transaction and
>>>>>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>>>>>> objets/sec rate
>>>>>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>>>>>> All views and transactions of a single session share
>>>>>>>>>>>>> (and cache)
>>>>>>>>>>>>> their object state. Otherwise I'd expect much smaller
>>>>>>>>>>>>> values.
>>>>>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed)
>>>>>>>>>>>>> reached
>>>>>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>>>>>> (which you
>>>>>>>>>>>>> used) is not that optimized.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>>>>>> complex metamodel. It contains 700 000 elements. The
>>>>>>>>>>>>> creation went
>>>>>>>>>>>>> pretty nicely (I did not measured it exactly as it was
>>>>>>>>>>>>> launched
>>>>>>>>>>>>> during a night, but it seems I got around 100 objects/sec
>>>>>>>>>>>>> rate in
>>>>>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>>>>>> Sounds not too bad.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Once the model is built the derby database is 222 MB
>>>>>>>>>>>>> (which - I
>>>>>>>>>>>>> heard - is not so big for derby).
>>>>>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>>>>>> To be honest, I'm really no database expert (although I
>>>>>>>>>>>>> can write
>>>>>>>>>>>>> simple SQL statements).
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Retrieving the distant resource and calling eAllContents()
>>>>>>>>>>>>> on it, I
>>>>>>>>>>>>> get a 50 Objects/sec rate at best, which mean my
>>>>>>>>>>>>> eAllContents() call
>>>>>>>>>>>>> would take 4 hours !
>>>>>>>>>>>>> Currently I'm not sure what exactly eAllContents() does do
>>>>>>>>>>>>> (iteration order and so). There are several CDO features
>>>>>>>>>>>>> that can
>>>>>>>>>>>>> have a major impact on load rates!
>>>>>>>>>>>>>
>>>>>>>>>>>>> - Collections (xrefs and containment) can be loaded
>>>>>>>>>>>>> lazily. I
>>>>>>>>>>>>> don't mean the target objects, which are lazy by default
>>>>>>>>>>>>> anyway,
>>>>>>>>>>>>> but even the target IDs that are in the collections. We
>>>>>>>>>>>>> call that
>>>>>>>>>>>>> "reference chunking" (but search for a better name is
>>>>>>>>>>>>> ongoing).
>>>>>>>>>>>>>
>>>>>>>>>>>>> public interface CDOSession extends
>>>>>>>>>>>>> CDOProtocolSession,
>>>>>>>>>>>>> IContainer<CDOView>
>>>>>>>>>>>>> {
>>>>>>>>>>>>> public int getReferenceChunkSize();
>>>>>>>>>>>>>
>>>>>>>>>>>>> public void setReferenceChunkSize(int
>>>>>>>>>>>>> referenceChunkSize);
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> - Loading collection elements (target objects) can be
>>>>>>>>>>>>> batched (the
>>>>>>>>>>>>> current name is even worse)
>>>>>>>>>>>>>
>>>>>>>>>>>>> public interface CDOView extends CDOProtocolView,
>>>>>>>>>>>>> INotifier
>>>>>>>>>>>>> {
>>>>>>>>>>>>> public int getLoadRevisionCollectionChunkSize();
>>>>>>>>>>>>>
>>>>>>>>>>>>> public void setLoadRevisionCollectionChunkSize(int
>>>>>>>>>>>>> loadRevisionCollectionChunkSize);
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> - One of the most sophisticated feature is automatic
>>>>>>>>>>>>> model usage
>>>>>>>>>>>>> analyzation. The result are fetch rules that are sent to
>>>>>>>>>>>>> the
>>>>>>>>>>>>> server. When later objects are loaded from the server,
>>>>>>>>>>>>> it can
>>>>>>>>>>>>> answer with additional objects that are likely to be
>>>>>>>>>>>>> needed by the
>>>>>>>>>>>>> client in the near future.
>>>>>>>>>>>>>
>>>>>>>>>>>>> public class CDOViewImpl extends
>>>>>>>>>>>>> org.eclipse.net4j.internal.util.event.Notifier
>>>>>>>>>>>>> implements
>>>>>>>>>>>>> CDOView, CDOIDProvider, Adapter.Internal
>>>>>>>>>>>>> {
>>>>>>>>>>>>> public CDOFeatureAnalyzer getFeatureAnalyzer()
>>>>>>>>>>>>> {
>>>>>>>>>>>>> return featureAnalyzer;
>>>>>>>>>>>>> }
>>>>>>>>>>>>>
>>>>>>>>>>>>> public void setFeatureAnalyzer(CDOFeatureAnalyzer
>>>>>>>>>>>>> featureAnalyzer)
>>>>>>>>>>>>> {
>>>>>>>>>>>>> this.featureAnalyzer = featureAnalyzer == null ?
>>>>>>>>>>>>> CDOFeatureAnalyzer.NOOP : featureAnalyzer;
>>>>>>>>>>>>> }
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> - There's a SmartReadAheadThread (if you're curious,
>>>>>>>>>>>>> please ask
>>>>>>>>>>>>> Simon). - Caches can be configured
>>>>>>>>>>>>> - ...
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Known issues of the DBStore:
>>>>>>>>>>>>> - When in auditing mode updates are always written as
>>>>>>>>>>>>> complete
>>>>>>>>>>>>> inserts (by design) - When configuring toManyReferences
>>>>>>>>>>>>> to a value
>>>>>>>>>>>>> different from LIKE_ATTRIBUTES (which is not implemented
>>>>>>>>>>>>> yet) it
>>>>>>>>>>>>> is very slow. - No (few) prepared
Re: [CDO] reading/writting throughput performances (SUCCESS) [message #124902 is a reply to message #124736] Mon, 02 June 2008 12:26 Go to previous messageGo to next message
Cedric Brun is currently offline Cedric BrunFriend
Messages: 431
Registered: July 2009
Senior Member
Hi Eike and Martin,

Thanks a lot for your help, I don't think I would have managed to get
through this "jar hell" without it !

I'm now going to benchmark the hibernate store with the same test case than
the dbstore (complex metamodel - big model - eAllContents throughput) and
gives you the figures, it might be of an interest even if it's a stupid
test for "interaction based" software.

Cédric

Eike Stepper wrote:

> Martin,
>
> In the console log snippet below, please notice that it is the first
> commit transaction signal and that there are no new packages contained.
> This is caused by the client (test case) that didn't register the used
> package with the client session before using it. The following snippet
> uses the new automatic registry:
>
> | *private *CDOSession createSession()
> {
> IConnector connector =
>
(IConnector)IPluginContainer.INSTANCE.getElement("org.eclipse.net4j.connectors ",
> "jvm", "default"); System.out.println(connector);
>
> CDOSessionConfiguration configuration =
> CDOUtil.createSessionConfiguration();
> configuration.setConnector(connector);
> configuration.setRepositoryName(REPO_NAME);
> configuration.setDemandPopulatingPackageRegistry(); *return
> *configuration.openSession();
> }|
>
>
> Now the test cases pass properly!!!
> Please see the attached log file.
>
> Cheers
> /Eike
>
>
>
> Eike Stepper schrieb:
>> Hi Martin,
>>
>> Ah, now with the new mapping I get a big step further!
>> As I said, Cedric's test code contained some bugs, too. IIRC a TCP
>> acceptor was created but the client uses a JVMConnector, and stuff
>> like this.
>> You could try to overcome the exception below by adding the following
>> to the server code somewhere:
>>
>> | IPluginContainer.INSTANCE.getElement("org.eclipse.net4j.acceptors ",
>> | "jvm", "default");|
>>
>>
>>
>> Better just use the attached zip because there may be other changes
>> that I don't remember in detail anymore.
>> Now I run into another exception:
>>
>> Thread-4 [debug.signal] ================ Indicating
>> CommitTransactionIndication
>> Thread-4 [debug] Created
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
>> repository repo1
>> Thread-4 [debug] Created
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
>> repository repo1
>> Thread-4 [debug] Created
>> org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Writer for
>> repository repo1
>> Thread-4 [debug.protocol] Reading 0 new packages
>> Thread-4 [debug.protocol] Reading 2 new objects
>> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
>> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
>> Thread-4 [debug.model] Reading CDOID of type 0 (NULL)
>> Thread-4 [debug.revision] Reading revision: ID=oid1,
>> classRef=CDOClassRef(http://www.eclipse.org/emf/CDO/resource/1.0.0,
>> 0), className=CDOResource, version=1, created=0, revised=0,
>> resource=oid1, container=NULL, feature=0
>> Thread-4 [debug.revision] Read feature CDOFeature(ID=9, name=path,
>> type=STRING, referenceType=null): /res2
>> Thread-4 [debug.revision] Read feature CDOFeature(ID=2, name=contents,
>> type=OBJECT, referenceType=CDOClass(ID=0, name=CDOObject)): size=1
>> Thread-4 [debug.model] Reading CDOID of type 3 (TEMP_OBJECT)
>> Thread-4 [debug.revision] oid2
>> [ERROR] ClassRef unresolveable:
>> CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
>> java.lang.IllegalStateException: ClassRef unresolveable:
>> CDOClassRef(http://www.eclipse.org/modeling/cdo/bug/names, 0)
>> at
>>
org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionIm pl. <init>(CDORevisionImpl.java:116)
>> at
>>
org.eclipse.emf.cdo.protocol.revision.CDORevisionUtil.read(C DORevisionUtil.java:48)
>> at
>>
org.eclipse.emf.cdo.internal.server.protocol.CommitTransacti onIndication.indicating(CommitTransactionIndication.java:95)
>> at
>>
org.eclipse.net4j.signal.IndicationWithResponse.execute(Indi cationWithResponse.java:46)
>> at org.eclipse.net4j.signal.Signal.runSync(Signal.java:143)
>> at org.eclipse.net4j.signal.Signal.run(Signal.java:124)
>> at
>>
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Threa dPoolExecutor.java:650)
>> at
>>
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoo lExecutor.java:675)
>> at java.lang.Thread.run(Thread.java:595)
>>
>> Cheers
>> /Eike
>>
>>
>>
>> Martin Taal schrieb:
>>> Hi Eike, Cedric,
>>> I can't say to much about net4j.db versus net4j.db.hsqldb.
>>>
>>> You are correct that the hibernate.libraries plugin should have
>>> Eclipse-BuddyPolicy: dependent (or another way to use the classpath
>>> of the dependent plugins). Btw, I agree that registered is better as
>>> afaik dependent gets slow which larger plugin environments.
>>>
>>> The reason that cglib is used is because one of the class mappings in
>>> org.eclipse.emf.cdo.server.hibernate/mappings/meta.hbm/xml did not
>>> have the lazy="false" directive. I added this and now I get another
>>> exception (see below). So this 'solves' the problem. If you do a get
>>> latest of this file then I think this problem is 'overcome'.
>>>
>>> Overall I still do not see why it went wrong. As far as I can see the
>>> cglib library could not find the hibernate class, which is strange as
>>> they are in the same plugin??
>>> The cdo testcases don't have this problem and neither does Teneo.
>>>
>>> As it does not occur anymore we can ignore it for now (not very
>>> satisfactory but there are other things to do)... Unless someone else
>>> has an idea how to handle this ofcourse.
>>>
>>> gr. Martin
>>>
>>> java.lang.IllegalStateException: acceptor == null
>>> at
>>>
org.eclipse.net4j.internal.jvm.JVMClientConnector.doBeforeAc tivate(JVMClientConnector.java:57)
>>>
>>> at
>>>
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:56)
>>>
>>> at
>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>
>>> at
>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>
>>> at
>>>
org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:260)
>>>
>>> at
>>>
org.eclipse.emf.internal.cdo.util.ChannelInjector.getConnect or(ChannelInjector.java:74)
>>>
>>> at
>>>
org.eclipse.emf.internal.cdo.util.ChannelInjector.process(Ch annelInjector.java:41)
>>>
>>> at
>>>
org.eclipse.net4j.internal.util.container.ManagedContainer.p ostProcessElement(ManagedContainer.java:407)
>>>
>>> at
>>>
org.eclipse.net4j.internal.util.container.ManagedContainer.g etElement(ManagedContainer.java:259)
>>>
>>> at
>>>
org.eclipse.cdo.bug.hibernate.HibernateServer.createSession( HibernateServer.java:93)
>>>
>>> at
>>>
org.eclipse.cdo.bug.unit.LaunchServerTest.testStringValue(La unchServerTest.java:43)
>>>
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at junit.framework.TestCase.runTest(TestCase.java:164)
>>> at junit.framework.TestCase.runBare(TestCase.java:130)
>>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>>> at junit.framework.TestResult.run(TestResult.java:109)
>>> at junit.framework.TestCase.run(TestCase.java:120)
>>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>>> at junit.framework.TestSuite.run(TestSuite.java:225)
>>> at
>>>
org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>>
>>> at
>>>
org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>>
>>> at
>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>>
>>> at
>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>>
>>> at
>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>>
>>> at
>>>
org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>>
>>> at
>>>
org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>>
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at
>>>
org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hod(EclipseAppContainer.java:547)
>>>
>>> at
>>>
org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>>
>>> at
>>>
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:106)
>>>
>>> at
>>>
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:76)
>>>
>>> at
>>>
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:362)
>>>
>>> at
>>>
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:175)
>>>
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at
>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>
>>> at
>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>
>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 564)
>>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>>> at org.eclipse.equinox.launcher.Main.run(Main.java:1251)
>>> at org.eclipse.equinox.launcher.Main.main(Main.java:1227)
>>>
>>>
>>>
>>> Eike Stepper wrote:
>>>> Hi,
>>>>
>>>> Here is a diagram of the dependencies of the relevant plugins
>>>> (please correct me if something is wrong).
>>>> The black arrows are ordinary downstream dependencies (Require-Bundle).
>>>> The red arrows are upstream dependencies (Eclipse-BuddyPolicy:
>>>> dependent).
>>>>
>>>>
>>>>
>>>> For research purposes I added code to the libraries plugin that
>>>> tries to reflectively load CDOFeatureImpl and that is not a problem!
>>>> It seems to me as if our problem is not class loading related
>>>> because the hibernate.jar should be able to see the needed classes.
>>>> I believe this is either a bug in Hibernate or our wrong usage of
>>>> Hibernate. I tend to believe the latter ;-)
>>>> I put a breakpoint in
>>>>
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping .EntityEntityModeToTuplizerMapping(PersistentClass,
>>>> EntityMetamodel)
>>>> to see how the tuplizers are created. I'm too unexperienced with
>>>> Hibernate to get a clue about what happens there...
>>>>
>>>> Btw. I'd prefer to see the application plugin depend on net4j.db
>>>> instead of net4j.db.hsqldb.
>>>> But it seems as if the BuddyPolicy in net4j.db is not "reexported"
>>>> so that the application can see the hsqldb.jar then ;-(
>>>> I posted a respective question to equinox...
>>>>
>>>> Cheers
>>>> /Eike
>>>>
>>>>
>>>> Eike Stepper schrieb:
>>>>> Hi guys,
>>>>>
>>>>> I can confirm, making these 3rd party libraries with their own
>>>>> classloading run in OSGi is a nightmare! I took me hours teach
>>>>> where the hsqldb driver is. On the way I came over different kinds
>>>>> of classloading related errors.
>>>>>
>>>>> First I removed all the jars from the test plugin (the one Cedric
>>>>> provided). They're already in the cdo.server.hibernate.libraries
>>>>> plugin which, in fact, needs the buddy policy set to dependent. I
>>>>> think this last change needs to be committed to CVS! Btw. I'd
>>>>> prefer to use *registered* buddies instead of making all dependent
>>>>> bundles visible.
>>>>>
>>>>> The test plugin then needs to provide the database driver.
>>>>> Therefore I added a dependency on the org.eclipse.net4j.db.hsqldb
>>>>> plugin.
>>>>>
>>>>> With this setup I can start the server without CNFE, NCDFE, CCI and
>>>>> the like. At this point I get the following exception, which seems
>>>>> the same as the one Cedric observed in the end:
>>>>>
>>>>> net.sf.cglib.core.CodeGenerationException:
>>>>> java.lang.reflect.InvocationTargetException-->null
>>>>> at
>>>>>
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:237)
>>>>>
>>>>> at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
>>>>> at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
>>>>> at
>>>>>
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:127)
>>>>>
>>>>> at
>>>>>
org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstant iate(CGLIBProxyFactory.java:43)
>>>>>
>>>>> at
>>>>>
org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFact ory(PojoEntityTuplizer.java:162)
>>>>>
>>>>> at
>>>>>
org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
>>>>>
>>>>> at
>>>>>
org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
>>>>>
>>>>> at
>>>>>
org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping . <init>(EntityEntityModeToTuplizerMapping.java:56)
>>>>>
>>>>> at
>>>>>
org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
>>>>>
>>>>> at
>>>>>
org.hibernate.persister.entity.AbstractEntityPersister.<init >(AbstractEntityPersister.java:434)
>>>>>
>>>>> at
>>>>>
org.hibernate.persister.entity.JoinedSubclassEntityPersister . <init>(JoinedSubclassEntityPersister.java:91)
>>>>>
>>>>> at
>>>>>
org.hibernate.persister.PersisterFactory.createClassPersiste r(PersisterFactory.java:58)
>>>>>
>>>>> at
>>>>>
org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
>>>>>
>>>>> at
>>>>>
org.hibernate.cfg.Configuration.buildSessionFactory(Configur ation.java:1294)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getSessionFactory(HibernatePackageHandler.java:335 )
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.readPackageInfos(HibernatePackageHandler.java:293)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.HibernatePacka geHandler.getCDOPackageInfos(HibernatePackageHandler.java:21 5)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.HibernateStore Reader.readPackageInfos(HibernateStoreReader.java:87)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.internal.server.PackageManager.doActivat e(PackageManager.java:72)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.internal.server.Repository.activateRepos itory(Repository.java:264)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.internal.server.Repository.doActivate(Re pository.java:251)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.internal.util.lifecycle.Lifecycle.activate (Lifecycle.java:57)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:71)
>>>>>
>>>>> at
>>>>>
org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(Life cycleUtil.java:61)
>>>>>
>>>>> at
>>>>>
org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOSe rverUtil.java:67)
>>>>>
>>>>> at
>>>>> org.eclipse.cdo.bug.LaunchServerTest.setUp(LaunchServerTest. java:54)
>>>>> at junit.framework.TestCase.runBare(TestCase.java:128)
>>>>> at junit.framework.TestResult$1.protect(TestResult.java:106)
>>>>> at junit.framework.TestResult.runProtected(TestResult.java:124)
>>>>> at junit.framework.TestResult.run(TestResult.java:109)
>>>>> at junit.framework.TestCase.run(TestCase.java:120)
>>>>> at junit.framework.TestSuite.runTest(TestSuite.java:230)
>>>>> at junit.framework.TestSuite.run(TestSuite.java:225)
>>>>> at
>>>>>
org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestRefer ence.run(JUnit3TestReference.java:130)
>>>>>
>>>>> at
>>>>>
org.eclipse.jdt.internal.junit.runner.TestExecution.run(Test Execution.java:38)
>>>>>
>>>>> at
>>>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:460)
>>>>>
>>>>> at
>>>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTe sts(RemoteTestRunner.java:673)
>>>>>
>>>>> at
>>>>>
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(R emoteTestRunner.java:386)
>>>>>
>>>>> at
>>>>>
org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunne r.main(RemotePluginTestRunner.java:62)
>>>>>
>>>>> at
>>>>>
org.eclipse.pde.internal.junit.runtime.CoreTestApplication.r un(CoreTestApplication.java:23)
>>>>>
>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>>> at
>>>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>>
>>>>> at
>>>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>>
>>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>>> at
>>>>>
org.eclipse.equinox.internal.app.EclipseAppContainer.callMet hodWithException(EclipseAppContainer.java:574)
>>>>>
>>>>> at
>>>>>
org.eclipse.equinox.internal.app.EclipseAppHandle.run(Eclips eAppHandle.java:195)
>>>>>
>>>>> at
>>>>>
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .runApplication(EclipseAppLauncher.java:110)
>>>>>
>>>>> at
>>>>>
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher .start(EclipseAppLauncher.java:79)
>>>>>
>>>>> at
>>>>>
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:379)
>>>>>
>>>>> at
>>>>>
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:179)
>>>>>
>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>>> at
>>>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>>
>>>>> at
>>>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>>
>>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>>> at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java: 549)
>>>>> at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
>>>>> at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
>>>>> at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
>>>>> Caused by: java.lang.reflect.InvocationTargetException
>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>>> at
>>>>>
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
>>>>>
>>>>> at
>>>>>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
>>>>>
>>>>> at java.lang.reflect.Method.invoke(Method.java:585)
>>>>> at
>>>>> net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java :384)
>>>>> at
>>>>>
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>>
>>>>> ... 61 more
>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>> org/hibernate/proxy/HibernateProxy
>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>> ... 67 more
>>>>>
>>>>> I must admit that I'm still not sure about te fundamental interwork
>>>>> between Hibernate and the user defined meta model. It seems as if
>>>>> asm and cglib are somewhere in between but I have no idea why at
>>>>> all. I thought we have implemented a bunch of static Hibernate
>>>>> interfaces to make the CDORevision instances known to Hibernate.
>>>>> Please somebody explain why we need runtime byte code engineering?
>>>>> Is there some configuration missing to tell Hibernate to use our
>>>>> special tuplizers?
>>>>>
>>>>> I have changed several things in the code of the test plugin and
>>>>> since it's quite small now that the jars are removed, I attach my
>>>>> version of the zip here (including a JUnit Plugin launch config).
>>>>> And don't forget to update the cdo.server.hibernate.libraries
>>>>> plugin from CVS to get the new buddy policy!
>>>>>
>>>>> Cheers
>>>>> /Eike
>>>>>
>>>>> Martin Taal schrieb:
>>>>>> Hi Cédric,
>>>>>> I looked at it for many hours trying different things (using your
>>>>>> testcase) but I am kind of stuck with this (getting the same error
>>>>>> as you). The difference I can see with the way I run the
>>>>>> cdo.hibernate testcases (as a junit test) and how your testcase is
>>>>>> run (junit plugin test). This for sure means difference in class
>>>>>> loader behavior.
>>>>>>
>>>>>> Eike, do you have an idea? I am not sure how classloading works
>>>>>> when you start a cdo server in a plugin. Which plugins are then
>>>>>> available in the cdo server? The testcases can be downloaded from
>>>>>> the link below.
>>>>>>
>>>>>> gr. Martin
>>>>>>
>>>>>> Cédric Brun wrote:
>>>>>>> Thanks a lot ! I'm looking forward to your advices !
>>>>>>>
>>>>>>> Cédric
>>>>>>>
>>>>>>> Martin Taal wrote:
>>>>>>>
>>>>>>>> I am downloading your zip-file. I don't have time to look at it
>>>>>>>> right away
>>>>>>>> but I will do my best later this evening.
>>>>>>>>
>>>>>>>> gr. Martin
>>>>>>>>
>>>>>>>> Cédric Brun wrote:
>>>>>>>>> I tried to do the same things as in the CDO/Hibernate unit tests.
>>>>>>>>>
>>>>>>>>> Here's a zipped project trying to launch an HibernateServer
>>>>>>>>> with a unit
>>>>>>>>> test adding elements.
>>>>>>>>>
( http://cedric.brun.free.fr/Tortoose/org.eclipse.cdo-teneo-te st.zip)
>>>>>>>>> The
>>>>>>>>> libs I found are included in the same project, but I still have
>>>>>>>>> no luck
>>>>>>>>> and failling at :
>>>>>>>>>
>>>>>>>>> at
>>>>>>>>>
>>>>>>>
net.sf.cglib.core.AbstractClassGenerator.create(AbstractClas sGenerator.java:219)
>>>>>>>
>>>>>>>>> ... 62 more
>>>>>>>>> Caused by: java.lang.NoClassDefFoundError:
>>>>>>>>> org/hibernate/proxy/HibernateProxy
>>>>>>>>> at java.lang.ClassLoader.defineClass1(Native Method)
>>>>>>>>> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
>>>>>>>>> ... 68 more
>>>>>>>>>
>>>>>>>>> please note that the test project I provide really is a "quick
>>>>>>>>> and ugly"
>>>>>>>>> one ^^
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Cédric
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Martin Taal wrote:
>>>>>>>>>
>>>>>>>>>> Hmm, I can understand your headache. Classpath issues are the
>>>>>>>>>> most
>>>>>>>>>> annoying errors...
>>>>>>>>>>
>>>>>>>>>> In your junit test source file, what happens when you enter the
>>>>>>>>>> org.objectweb.asm.Type, can you source file see this class?
>>>>>>>>>> Do you have cglib in some other plugin which does not have asm?
>>>>>>>>>>
>>>>>>>>>> What I also find slightly strange is that cglib is used in
>>>>>>>>>> this case
>>>>>>>>>> because normally cdo objects are not proxied using cglib. Can
>>>>>>>>>> you post
>>>>>>>>>> the generated mapping? How does your cdo initialization code
>>>>>>>>>> look like?
>>>>>>>>>>
>>>>>>>>>> gr. Martin
>>>>>>>>>>
>>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>>> Hi Martin,
>>>>>>>>>>>
>>>>>>>>>>> and thanks for your quick answer ! what I did is the
>>>>>>>>>>> following :
>>>>>>>>>>>
>>>>>>>>>>> I used the org.eclipse.emf.cdo.server.hibernate.libraries
>>>>>>>>>>> bundle and
>>>>>>>>>>> added that :
>>>>>>>>>>>
>>>>>>>>>>> Bundle-ClassPath: lib/hibernate3.jar,
>>>>>>>>>>> lib/cglib-2.1.3.jar,
>>>>>>>>>>> lib/commons-collections-2.1.1.jar,
>>>>>>>>>>> lib/dom4j.jar,
>>>>>>>>>>> lib/jta.jar
>>>>>>>>>>> lib/asm-3.0.jar
>>>>>>>>>>>
>>>>>>>>>>> and this directive :
>>>>>>>>>>>
>>>>>>>>>>> Eclipse-BuddyPolicy: dependent
>>>>>>>>>>>
>>>>>>>>>>> as stated in
>>>>>>>>>>>
http://www.elver.org/hibernate/installation.html#Hibernate+L ibraries
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Then I don't get the same error, now when I start my own
>>>>>>>>>>> plugin (JUnit
>>>>>>>>>>> plugin test) depending on
>>>>>>>>>>> org.eclipse.emf.cdo.server.hibernate.libraries I get :
>>>>>>>>>>>
>>>>>>>>>>> java.lang.NoClassDefFoundError: org/objectweb/asm/Type
>>>>>>>>>>> at
>>>>>>>>>>> net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
>>>>>>>>>>> at
>>>>>>>>>>> net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
>>>>>>>>>>> at
>>>>>>>>>>> net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
>>>>>>>>>>> at
>>>>>>>>>>>
>>>>>>>
org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxy Factory(CGLIBLazyInitializer.java:117)
>>>>>>>
>>>>>>>>>>> These jars are such a headache ! Do you know - by chance -
>>>>>>>>>>> what's
>>>>>>>>>>> going on ?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Cédric
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Martin Taal wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Hi Cédric,
>>>>>>>>>>>> Most of the time this exception is thrown because hibernate
>>>>>>>>>>>> can't find
>>>>>>>>>>>> the class. A common cause is that the hibernate jar files
>>>>>>>>>>>> are located
>>>>>>>>>>>> in a separate plugin which can not reach the classes in
>>>>>>>>>>>> other plugins.
>>>>>>>>>>>> If you set the eclipse buddy policy of the hibernate plugin to
>>>>>>>>>>>> dependent then this can help.
>>>>>>>>>>>>
>>>>>>>>>>>> gr. Martin
>>>>>>>>>>>>
>>>>>>>>>>>> Cédric Brun wrote:
>>>>>>>>>>>>> Hi Simon and Eike,
>>>>>>>>>>>>>
>>>>>>>>>>>>> thanks for your feedback, now I know what I could expect in
>>>>>>>>>>>>> using
>>>>>>>>>>>>> optimized implementation, I'll have a try on the hibernate
>>>>>>>>>>>>> store and
>>>>>>>>>>>>> see if it is scaling in a better way.
>>>>>>>>>>>>>
>>>>>>>>>>>>> You gave me many pointers to explain the performances
>>>>>>>>>>>>> issues but in
>>>>>>>>>>>>> fact it seems that the SQL execution is taking so much time
>>>>>>>>>>>>> (not
>>>>>>>>>>>>> suprisingly in fact ;) . My first profile was wrong.
>>>>>>>>>>>>>
>>>>>>>>>>>>> So I'm installing the hibernate store retrieving all the
>>>>>>>>>>>>> source code
>>>>>>>>>>>>> from CVS, and I'm trying to launch the unit tests. I added
>>>>>>>>>>>>> many jars
>>>>>>>>>>>>> and everything gets compiled but most of the tests are
>>>>>>>>>>>>> failling with
>>>>>>>>>>>>> "
>>>>>>>>>>>>>
>>>>>>>>>>>>> "
>>>>>>>>>>>>> org.hibernate.MappingException: Could not determine type for:
>>>>>>>>>>>>>
>>>>>>>
org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.CDOTy peUserType,
>>>>>>>
>>>>>>>>>>>>> at table: cdo_features, for columns:
>>>>>>>>>>>>> [org.hibernate.mapping.Column(type)] "
>>>>>>>>>>>>>
>>>>>>>>>>>>> any hint ?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Cédric
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Simon McDuff wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> We noticed a performance degradation in the following case:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> When we fetch a collection of objects that contains
>>>>>>>>>>>>>> collections that
>>>>>>>>>>>>>> we don't want to use. Ex:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Model:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ClassB
>>>>>>>>>>>>>> {
>>>>>>>>>>>>>> int foo1;
>>>>>>>>>>>>>> List childrens1;
>>>>>>>>>>>>>> List childrens2;
>>>>>>>>>>>>>> List childrens3;
>>>>>>>>>>>>>> };
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Code:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Resource.contents contains objects of type ClassB.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> By fetching instances of classB, we will also fetched some
>>>>>>>>>>>>>> items in
>>>>>>>>>>>>>> the list(childrens1, childrens2, childrens3) The problem
>>>>>>>>>>>>>> we had.. is
>>>>>>>>>>>>>> we do not know if we want to use it. SO better not to
>>>>>>>>>>>>>> download them.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> So In our production(we used our own IStore), we never
>>>>>>>>>>>>>> download any
>>>>>>>>>>>>>> objects from collection. I'm working at the moment to put
>>>>>>>>>>>>>> in place
>>>>>>>>>>>>>> all feature we used in the current CDO. That one will be
>>>>>>>>>>>>>> part of
>>>>>>>>>>>>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=214477. To
>>>>>>>>>>>>>> begin
>>>>>>>>>>>>>> with,CDORevisionImpl needs to supports list that are 0
>>>>>>>>>>>>>> even if
>>>>>>>>>>>>>> referenceChunkSize == 0.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> It is true that we obtain good performance.
>>>>>>>>>>>>>> Worst case :
>>>>>>>>>>>>>> 1500 objects /sec (Real fetch from disk. Page that
>>>>>>>>>>>>>> contains the
>>>>>>>>>>>>>> objects, wasn't in the cache of the filesystem.)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Best case
>>>>>>>>>>>>>> 12 000 objects/Sec (Fetch objects that are already in the
>>>>>>>>>>>>>> case of
>>>>>>>>>>>>>> the filesystem)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> (These statistics always fetch objects from server to
>>>>>>>>>>>>>> client. The
>>>>>>>>>>>>>> cache client isn't used)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> We have another optimization one with SmartReadAhead but
>>>>>>>>>>>>>> for now
>>>>>>>>>>>>>> only work
>>>>>>>>>>>>>> for UI client. (for now) This is something we will
>>>>>>>>>>>>>> integrate as
>>>>>>>>>>>>>> well in CDO. But for now we concentrate on the other things.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I used an Object database. Based on my preliminary test
>>>>>>>>>>>>>> without CDO.
>>>>>>>>>>>>>> I compare
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hibernate vs Objectivity/EMF :
>>>>>>>>>>>>>> Objectivity/EMF is around 3 to 50 times faster than
>>>>>>>>>>>>>> Hibernate.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The worst.. you will get 30 to 240 objects/sec or
>>>>>>>>>>>>>> the best... you will get 500 to 4000 objects/sec
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Based on your comments... you are getting the worst (with
>>>>>>>>>>>>>> Derby)!!
>>>>>>>>>>>>>> :-)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Another comments about insertion.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> We found another problem when we insert data(DOn't know if
>>>>>>>>>>>>>> it is
>>>>>>>>>>>>>> still true). Resource.Contents is a unique list. Basically
>>>>>>>>>>>>>> each time
>>>>>>>>>>>>>> we insert one element, it needs to fetch all the
>>>>>>>>>>>>>> collection to see
>>>>>>>>>>>>>> if we already have this element. Basically.. it is time
>>>>>>>>>>>>>> consuming.
>>>>>>>>>>>>>> In our case we are not going through this stage to persist
>>>>>>>>>>>>>> our
>>>>>>>>>>>>>> objects... but the objects are not accessible through that
>>>>>>>>>>>>>> list.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> If speed is an issue for you!! We (You included :-)) can
>>>>>>>>>>>>>> optimize
>>>>>>>>>>>>>> it. What I like is Eike did a really good job doing that
>>>>>>>>>>>>>> framwork
>>>>>>>>>>>>>> and optimizations are easy to add. Also you can change
>>>>>>>>>>>>>> your back-end
>>>>>>>>>>>>>> without affecting you client side. (Maybe going to an Object
>>>>>>>>>>>>>> database!!) THis was one of the purpose of CDO!! :-)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Simon
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> "Eike Stepper" <stepper@sympedia.de> a écrit dans le
>>>>>>>>>>>>>> message de
>>>>>>>>>>>>>> news: 483E9332.6050800@sympedia.de... Hi Cédric,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> That sounds interesting!
>>>>>>>>>>>>>> Comments inline...
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Cédric Brun schrieb:
>>>>>>>>>>>>>> Hi Eike,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I've been messing around CDO lately and I hacked a few ugly
>>>>>>>>>>>>>> unit-tests measuring read/write throughput when I use CDO
>>>>>>>>>>>>>> (RC2).
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I'm using an embeded-derby database, two different metamodels
>>>>>>>>>>>>>> (complex one - 250 EClassifiers/300 features and a simple
>>>>>>>>>>>>>> one - 1
>>>>>>>>>>>>>> Classifier/3 Features)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The test is a "quick and dirty" one so please do not take
>>>>>>>>>>>>>> these
>>>>>>>>>>>>>> figures too seriously, I would just like to have your
>>>>>>>>>>>>>> input about
>>>>>>>>>>>>>> the "order of magnitude" I should expect or settings
>>>>>>>>>>>>>> affecting
>>>>>>>>>>>>>> seriously these performances. I tried both JVM and TCP
>>>>>>>>>>>>>> acceptor but
>>>>>>>>>>>>>> the performances are quite similar though JVM is a bit
>>>>>>>>>>>>>> faster.
>>>>>>>>>>>>>> Looks like a sign that the NIO socket channels are
>>>>>>>>>>>>>> efficient ,-)
>>>>>>>>>>>>>> You used localhost for TCP transport I guess?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * First case : building a small model (10000 elements)
>>>>>>>>>>>>>> with the
>>>>>>>>>>>>>> simple MM, only adding instances in an empty database :
>>>>>>>>>>>>>> commiting change on every add I get a 2 objects per second
>>>>>>>>>>>>>> rate.
>>>>>>>>>>>>>> commiting changes every 10 adds - I get a 30 objects per
>>>>>>>>>>>>>> second
>>>>>>>>>>>>>> rate.
>>>>>>>>>>>>>> Seems to be consistent with the fact that only for
>>>>>>>>>>>>>> commits there
>>>>>>>>>>>>>> is remote traffic. And the backend transaction
>>>>>>>>>>>>>> management is
>>>>>>>>>>>>>> another overhead. So the impact of the number
>>>>>>>>>>>>>> objects/commit
>>>>>>>>>>>>>> starts with bigger transactions.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> browsing the just commited elements opening a new
>>>>>>>>>>>>>> transaction and
>>>>>>>>>>>>>> getting a new Resource instance, I get around 30 000
>>>>>>>>>>>>>> objets/sec rate
>>>>>>>>>>>>>> just iterating thanks to Resource.getAllContents().
>>>>>>>>>>>>>> Hehe, this is a sign that client side caching works well:
>>>>>>>>>>>>>> All views and transactions of a single session share
>>>>>>>>>>>>>> (and cache)
>>>>>>>>>>>>>> their object state. Otherwise I'd expect much smaller
>>>>>>>>>>>>>> values.
>>>>>>>>>>>>>> With his ObjectivityStore implementation Simon (cc'ed)
>>>>>>>>>>>>>> reached
>>>>>>>>>>>>>> rates of several thousands objects/sec. But the DBStore
>>>>>>>>>>>>>> (which you
>>>>>>>>>>>>>> used) is not that optimized.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * Second case : I built a big model in the database using the
>>>>>>>>>>>>>> complex metamodel. It contains 700 000 elements. The
>>>>>>>>>>>>>> creation went
>>>>>>>>>>>>>> pretty nicely (I did not measured it exactly as it was
>>>>>>>>>>>>>> launched
>>>>>>>>>>>>>> during a night, but it seems I got around 100 objects/sec
>>>>>>>>>>>>>> rate in
>>>>>>>>>>>>>> writting as I was writting every 700 objects.
>>>>>>>>>>>>>> Sounds not too bad.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Once the model is built the derby database is 222 MB
>>>>>>>>>>>>>> (which - I
>>>>>>>>>>>>>> heard - is not so big for derby).
>>>>>>>>>>>>>> Hmm, I have no extensive experience with Derby.
>>>>>>>>>>>>>> To be honest, I'm really no database expert (although I
>>>>>>>>>>>>>> can write
>>>>>>>>>>>>>> simple SQL statements).
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Retrieving the distant resource and calling eAllContents()
>>>>>>>>>>>>>> on it, I
>>>>>>>>>>>>>> get a 50 Objects/sec rate at best, which mean my