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Two CDO servers on one DB [message #724608]

Mon, 12 September 2011 16:21

erpalma2003

Messages: 12
Registered: July 2011

Junior Member

Is it possible to run 2 cdo servers on a single db? I'm using dbstore and cdo 4. Concurrency problems?

[Updated on: Mon, 12 September 2011 16:21]

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Re: Two CDO servers on one DB [message #724613 is a reply to message #724608]

Mon, 12 September 2011 16:30

Eike Stepper

Messages: 6682
Registered: July 2009

Senior Member

Am 12.09.2011 18:21, schrieb erpalma2003:
> Is it possible to run 2 cdo servers on a single db? I'm using dbstore and cdo 4. Concurrency problems?
It is not possible. Not so much because of concurrency problems (the DBStore uses proper DB transactions to modify all
data) but because each CDO server

a) generally maintains important internal transient state
b) which, in particular, controls the change notifications that are being sent to other clients for successful commits.

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

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Re: Two CDO servers on one DB [message #724614 is a reply to message #724608]

Mon, 12 September 2011 16:31

Stefan Winkler

Messages: 307
Registered: July 2009
Location: Germany

Senior Member

Hi,

I assume you mean "on a single db schema"? Why would you want to do
that? What exactly is your use case?

Concurrency problems? Definately!

I.e., the CDO server creates an entry that it is started, the second
server would think that an earlier process has crashed and would start a
recovery process.

In addition, a CDO server holds certain counters (e.g., max ID, max
branch ID etc.) in memory.

You can, however, use the same DB server if you are using different
repos and different DB users/schemas.

Cheers,
Stefan

Am 12.09.11 18:21, schrieb erpalma2003:
> Is it possible to run 2 cdo servers on a single db? I'm using dbstore
> and cdo 4. Concurrency problems?

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Re: Two CDO servers on one DB [message #724615 is a reply to message #724613]

Mon, 12 September 2011 16:33

Eike Stepper

Messages: 6682
Registered: July 2009

Senior Member

I forgot to ask why you would want to do this ;-)

We're supporting a couple of distributed server scenarios with the help of automatic replication on CDO protocol level,
e.g., offline clones or fail-over clusters. But they generally let the CDO servers operate on separate database instances.

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

Am 12.09.2011 18:30, schrieb Eike Stepper:
> Am 12.09.2011 18:21, schrieb erpalma2003:
>> Is it possible to run 2 cdo servers on a single db? I'm using dbstore and cdo 4. Concurrency problems?
> It is not possible. Not so much because of concurrency problems (the DBStore uses proper DB transactions to modify all
> data) but because each CDO server
>
> a) generally maintains important internal transient state
> b) which, in particular, controls the change notifications that are being sent to other clients for successful commits.
>
> Cheers
> /Eike
>
> ----
> http://www.esc-net.de
> http://thegordian.blogspot.com
> http://twitter.com/eikestepper
>
>

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

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Re: Two CDO servers on one DB [message #724617 is a reply to message #724614]

Mon, 12 September 2011 16:45

Erdal Karaca

Messages: 854
Registered: July 2009

Senior Member

Stefan Winkler wrote on Mon, 12 September 2011 12:31

I assume you mean "on a single db schema"? Why would you want to do
that? What exactly is your use case?

Wouldn't that be possible by defining table name prefixes for each of the servers?

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Re: Two CDO servers on one DB [message #724630 is a reply to message #724617]

Mon, 12 September 2011 17:28

erpalma2003

Messages: 12
Registered: July 2011

Junior Member

I need a single application (with much data) to be used across different countries at the same time, on the same schema. I have the ability to use a high bandwidth mysql machine but cdo server must run on a machine connected over ADSL (poor up speed). Actually i'm using a SSH tunnel to forward cdo server to the other countries but it is quite slow. A replicated cdo/mysql setup would be the best in term of speed and reliability.

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Re: Two CDO servers on one DB [message #724634 is a reply to message #724617]

Mon, 12 September 2011 17:28

Eike Stepper

Messages: 6682
Registered: July 2009

Senior Member

Am 12.09.2011 18:45, schrieb Erdal Karaca:
> Stefan Winkler wrote on Mon, 12 September 2011 12:31
>> I assume you mean "on a single db schema"? Why would you want to do that? What exactly is your use case?
>
>
> Wouldn't that be possible by defining table name prefixes for each of the servers?
No, IIRC the table name prefixes only apply for *mapped* tables, not the system tables that Stefan mentioned.

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper

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