UserTransaction and EntityTransaction

[Tang Yue]

UserTransction manages JTA transactions while EntityTransction is responsible foir resource-local transactions.
What if this happens:
ut.begin();
et=em.getEntityTransaction();
et.begin(); // what happens here? an IllegalStateException? Or the outer transaction is suspended?
...

[Chaminda Amarasinghe]

Im not 100% sure. But I think this is illegal. Because nested transactions not allowed.

[Ralph Jaus]

That shouldn't be a problem: JTA transactions and entity transactions don't influence each other (see core spec. 13.3.3, footnote 63).
[ November 21, 2008: Message edited by: Ralph Jaus ]

[Chaminda Amarasinghe]

JTA Transactions and User Transactions :roll: User Transactions are also JTA Transactions.

[Ralph Jaus]

Yeah In the first version I had writen "JTA transactions and user transactions" instead of "JTA transactions and entity transactions". I corrected the mistake as fast as I could, but no chance, Chaminda was faster

[Chaminda Amarasinghe]

Its ok Ralph....

But problem is still remaining. the section you pointed was not much helpful

Do you think this is possible?

[Ralph Jaus]

Hi Cham,

Do you think this is possible?

Yes, see for example Pro EJB 3 chapter 5, page 130:

Resource transactions [= entity transactions, remark from me] may be freely started and committed any number of times within a JTA transaction without impacting the state of the JTA transactions.

This can be used for example to decouple persisting log entries from committing resp. rolling back the business transactions.

I also tried this example with starting and committing an entity transaction within a JTA transaction that will be rolled back. Worked as expected: The business data were not in the database while the log entries are.

[Chaminda Amarasinghe]

Thanks Ralph for the infor