[hibernate-dev] Exceptions thrown in a tx synchronization are eaten

[Steve Ebersole]

The main reason is because allowing these exceptions to be (re-)thrown 
opens up mixed heuristic issues.

Also bear in mind that we have no clue about the nature of the process 
being performed by the synch.  It highly likely that "failure" of the 
synch should *not* rollback the main transaction.  This is really one of 
the 50/50 data points.  We really just do not know, and the contract 
gives us no way to know.  However, if rolling back is that important it 
is in fact possible in any case i can imagine to pass the 
o.h.Transaction into the Synchronization constructor and actually roll 
it back if an error occurs.


On 03/24/2010 03:54 PM, Adam Warski wrote:
> Hello,
>
> if a transaction synchronization throws an exception, is it only logged, and not thrown further (see org.hibernate.transaction.JDBCTransaction, line 273). Is there some reason for this?
>
> As Envers uses tx synchronizations quite extensively, when an exception is thrown in the synchronization, I roll back the transaction manually. So, no data is persisted (which is the desired behavior), but the client isn't notified in any way that something went wrong; for the client, the operation behaves as if the tx commited successfully.
>
> I suspect that maybe some applications rely on the fact that the exception is eaten and not re-thrown. If there are no contra-arguments to throw the exceptions, maybe a good solution would be to re-throw the exception is the transaction is already marked for rollback? Or if it was marked for rollback in the synchronization?
>
> The related JIRA issues are:
> http://opensource.atlassian.com/projects/hibernate/browse/HHH-3543
> http://opensource.atlassian.com/projects/hibernate/browse/HHH-4721
>
> By the way, how does Hibernate Search deal with such situations? I looked at PostTransactionWorkQueueSynchronization, and it seems that it's possible that the transaction commits, but the data isn't indexed properly, if the queueingProcessor.performWorks throws an exception?
>

-- 
steve at hibernate.org
http://hibernate.org