Re: [eclipselink-users] Message Persistence for JMS Coordinated Cache

[Gordon Yorke <gordon.yorke@xxxxxxxxxx>]

As with most aspects of EclipseLink there is no simple answer.  If you have a read mostly application that contains a lot of the same data set or your stale data management depends on these messages then persisting the messages for recovery can be beneficial.  In a system where a lot of the same data changes repeatedly then one could expect the remote application to change the data before the JMS service recovers.

To aid in this decision consider the following:
1. How dependant is your stale data management on the message updates?
2. The longer you expect the JMS service to be down the less likely the messages will be of value.
3. The more static the data the more valuable the messages will be
4. The more volitile the data the less valuable the messages will be
5. The only consequence of losing messages is data that is 'stale' for a greater length of time.

I should also mention that as long as the Entities involved have versions any recovered message that contains old information will be ignored by EclipseLink so there is no functional drawback to using persistence messages.

--Gordon

Dave Muirhead wrote:

Hi Gordon-

Thank you for addressing my question.

My interpretation of your answer is that there is no particular benefit to using persistent JMS messages with Top/EclipseLink clustering.

For the benefit of those who might have the same question in the future and happen across this thread, would you please provide confirmation that this is in fact your guidance.

Thanks much,

Dave

On Thu, Nov 13, 2008 at 5:49 AM, Gordon Yorke <gordon.yorke@xxxxxxxxxx> wrote:

Hello Dave,
    If the JMS service fails you can assume that the cached objects will continue to be updated through normal application operation making the messages corresponding to those objects useless.  The longer the service is down the less useful the messages would be.
--Gordon

Dave Muirhead wrote:

When setting up an EclipseLink JMS Coordinated Cache, is it recommended to configure the JMS provider to use message persistence or not?

On one hand, it doesn't seem like message persistence would terribly beneficial, since newly started VMs would have no need to see cache modifications that occurred in the past. On the other hand, I can see wanting to preserve messages in the event the JMS provider fails.

Thanks in advance,

Dave

--

==========
Dave Muirhead
dmuirhead@xxxxxxxxx

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users
  

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

--

==========
Dave Muirhead
dmuirhead@xxxxxxxxx

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users