10.7.9. JTA Transaction Error Handling Handle Transaction Errors

Transaction errors are challenging to solve because they are often dependent on timing. Here are some common errors and ideas for troubleshooting them.


These guidelines do not apply to heuristic errors. If you experience heuristic errors, refer to Section 10.7.7, “Handle a Heuristic Outcome in a Transaction” and contact Red Hat Global Support Services for assistance.
The transaction timed out but the business logic thread did not notice

This type of error often manifests itself when Hibernate is unable to obtain a database connection for lazy loading. If it happens frequently, you can lengthen the timeout value. Refer to Section, “Configure the Transaction Manager”.

If that is not feasible, you may be able to tune your external environment to perform more quickly, or restructure your code to be more efficient. Contact Red Hat Global Support Services if you still have trouble with timeouts.
The transaction is already running on a thread, or you receive a NotSupportedException exception

The NotSupportedException exception usually indicates that you attempted to nest a JTA transaction, and this is not supported. If you were not attempting to nest a transaction, it is likely that another transaction was started in a thread pool task, but finished the task without suspending or ending the transaction.

Applications typically use UserTransaction, which handles this automatically. If so, there may be a problem with a framework.
If your code does use TransactionManager or Transaction methods directly, be aware of the following behavior when committing or rolling back a transaction. If your code uses TransactionManager methods to control your transactions, committing or rolling back a transaction disassociates the transaction from the current thread. However, if your code uses Transaction methods, the transaction may not be associated with the running thread, and you need to disassociate it from its threads manually, before returning it to the thread pool.
You are unable to enlist a second local resource

This error happens if you try to enlist a second non-XA resource into a transaction. If you need multiple resources in a transaction, they must be XA.