I forgot to mention, we're using POJOs, not EJBs so annotating methods with @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW) isn't an option for us.
Also, as we always want each DB to have independent transactions, we'd prefer to find a global configuration option if possible rather than having to modify our code.
Hi Rob, I have a similar setup as you, read from one DB, write to another.
I don't see any potential issues in our scenarios. I think the JBoss folks decided to play it safe and always log the warning just in case someone is using this setting with multiple database being written to. In this case, there is a slim chance that some dbs are committed while others aren't. Keep in mind that the likelihood of an outage occurring during the commit sequence is very small.
In your current setup the dbs are still running with independent transactions but make it
appearto you that they run within the same transaction due to JBoss JTA transaction manager. In other words when JBoss TX Mgr commits each transactional resource it cannot be rolled back anymore which is exactly the behavior of an independent (local) transaction.
I agree that
option is cleaner to isolate reads in their own JTA transaction but I don't think it is required in our case either.
Are their other concerns that you may have?