Two databases, two persistence-units but one entity jar-file

[ville-ingman]

Hi all,

This message was initially sent to Hibernate forums, but Emmanuel from the Hibernate Team suggested to post this it here. Hibernate thread is http://forum.hibernate.org/viewtopic.php?p=2338630.


I'm trying to create two different database schemas from one entity jar-file. The point is that I need one DB for the actual data and exactly identical DB for backup purposes etc. My operative DB works just fine and all tables are created, but the problem is that my backup DB remains empty without any errors from Hibernate. I get no tables, no errors, no warnings and nothing seems to be wrong in log-files either. The other DB just remains empty.

Log-file is identical with both of these persistence-units. Hibernate tells me that this-n-that table not found in database etc and it leads to table creation in my operative database, like it should be. Nothing, absolutely nothing, happens to my backup persistence-unit.

I have JBoss 4.0.5.GA and Hibernate 3.2.1.GA. Both databases are empty and listed in deploy/postgres-ds.xml and they do exist before JBoss launch. My app is packed inside an EAR and my EJB-module has this persistence.xml listed below.

My persistence.xml:

<persistence-unit name="my-operative-db">
<jta-data-source>java:/my-operative-db</jta-data-source>
<jar-file>../entity-data.jar</jar-file>
<properties...
</persistence-unit>
<persistence-unit name="my-backup-db">
<jta-data-source>java:/my-backup-db</jta-data-source>
<jar-file>../entity-data.jar</jar-file>
<properties...
</persistence-unit>

Does any one have similar problems? Am I missing something or is there something wrong in JBoss/Hibernate? Some one please try this out and post your comments.

I didn't open a JIRA issue on this yet. I'd like to wait if someone has more info on this and perhaps a JIRA issue isn't needed. Atleat I keep my fingers crossed on that. :)

Thanks for advance,
Ville

[dkalna]

Hi Ville,

I think you have to explicitly specify your Entities in persistence.xml, otherwise they will deployed to "default" = first one, only.

<persistence-unit name=" my-operative-db ">
<jta-data-source> java:/my-operative-db </jta-data-source>
<jar-file> ../entity-data.jar </jar-file>
com.yourhost.domain.Entity1
com.yourhost.domain.Entity2
<properties...
</persistence-unit>
<persistence-unit name=" my-backup-db ">
<jta-data-source> java:/my-backup-db </jta-data-source>
<jar-file> ../entity-data.jar </jar-file>
com.yourhost.domain.Entity1
com.yourhost.domain.Entity2
<properties...
</persistence-unit>

Bye
Dalibor

[dkalna]

oooops, correction, these have to be inside element:

com.yourhost.domain.Entity1
com.yourhost.domain.Entity2

Dalibor

[dkalna]

sorry, he is not showing class XML element...

[ville-ingman]

Thanks for your reply Dalibor,

I'm afraid that listing all my entities is not an option for me in this project I'm working on. My entity-jar contents is not for me to decide and there are dynamically generated class-files included in these jar-files etc.

So. The only way I can make this happen is to use <jar-file> -tag and the runtime environment JBoss+Hibernate take care of the rest. I just need a backup database that is an identical copy of my operative database and entity modifications are published to these two databases. Nothing more, nothing less.

Unfortunately this issue is still open. More ideas from you Dalibor or someone else?

As far as I'm concerned, this is a bug in JBoss+Hibernate combination. Could someone in the JBoss team check this out and see if a JIRA issue have to be raised?

Thanks for advance for more comments on this,
Ville

[ville-ingman]

Hi again,

Unfortunately this issue is still open. Has some one checked this out yet?

Regards,
Ville Ingman

[alrubinger]

Looks like:

http://jira.jboss.com/jira/browse/EJBTHREE-560

...you can watch or vote on it :)

S,
ALR