Hi,

at the moment I'm working on a MongoDB EAR-project using Wildfly 10. As an additional persistence layer I would like to use Hibernate OGM 5. My project consists of multiple EJB modules of which several use the MongoDB database.

I added the OGM modules to an EJB as described in the documentation. I put a persistence.xml to the META-INF directory of the same module, too. Everything works as expected.

Now my questions/problem:

- If I create a similar project with a traditional datasource in WF I am able to create a config module with the persistence.xml, add this module as a dependency to other EJB modules. In such a configuration all entities in all modules are auto discovered (no need to put them in the persistence.xml) and I need to add the persistence.xml just once. Is it possible to achive the same behaviour when using Hibernate OGM?

- If this is not possible, do I have to put a persistence.xml file in every EJB module? Is auto-discovery possible in such a configuration? Is the connection between the modules shared or does every EJB open up it's own connection to the MongoDB database?

- Are there better ways to configure OGM persistence in such an environment?

If I should provide additional information, please let me know. Thanks in advance for your help.

Dieter

Hi,



Awesome :)



I haven't tested this but if it was working before it should work now as well. Are you asking because you tried and it does not work?



At the moment, every EJB will have it's own connection.

You should be able to configure OGM in the same way you configure ORM or another JPA implementation, the main difference is that you cannot configure datasources or JDBC connections.

I hope this help, please let us know if there is some use case that does not work and we will check.

Cheers,
Davide

Hi,


To be a little bit more precise, I tested it with the Hibernate OR(!)M mapper used in Wildfly. The config module with the persistence.xml (that contains a JNDI datasource) is a dependency for all dependent EJB modules using the persistence context. In such a config there's no need to list the classes in the persistence.xml (auto-discovery). It's not even possible because the Entities are unknown to the config module. This is what I tested. And it worked.

In your answer I read between the lines that my above scenario is not possible, because I cannot reuse the persistence context from a dependency. Do you know if auto-discovery of entities is possible? When I do not list the classes in the persistence.xml they are not discovered. I can post my persistence.xml file if you want, but it looks like the one from the docs.

Thanks for your help.

Dieter

I checked the JPA 2 specification (paragraph 8.2.2 Persistence Unit Scope):



OGM should work in the same way, if you find that something is not matching, please, provide us with an example and we will check.

I hope this help,
Davide

In the meanwhile,
I've created an issue to add an integration test: https://hibernate.atlassian.net/browse/OGM-999

If you can describe your use case we can add it to our build.

Cheers,
Davide

Hello,

thanks for your comment.

It will take a while to create the example, because I must strip down my project to the relevant parts. Can you say something about auto-discovery of entities?

Dieter

Auto-discovery is defined as well by the spec (8.2.1.6.1):



So, it should be able to auto-discover the classes contained in the same JAR where the persistence-unit is defined.

You can also set the jar-file property in the persistence.xml to define a JAR containing the mapping files (I'm not sure if this can help).

Davide