Application Managed Transaction (JTA) and Container Managed Persistence (JPA)

Question

Currently I'm working on a software that consists of two parts.

One part is a kind of company wide framework for data processing (kind of self written process engine). It uses JTA UserTransactions and calls a sub processor that is written by our project.

Our "sub processor" is an application on it's own. It uses container managed persistence via JPA. (Websphere with OpenJPA)

A typical workflow is: process engine loads process data -> start user transaction -> calls sub processor -> writes process data -> ends user transaction

We now experience the following wrong behavior: The user transaction is committed in the process engine, all the meta data of the process is stored into the db BUT the data the entity manager holds inside our sub processor application is not written to the db.

Is there some manual communication necessary to commit the content of our entity manager?

Answer 1

The Problem we observed had nothing to do with JTA and transactions.

We tried to clean a blob column but this was not possible. I will create another question for it.