Managed Connections not returned into pool

[tom_doehler]

Hi,

i have a problem concerning JBoss managed connections and connection pooling. I think I have found the problem, but I don't know exactly how I can solve it. The problem is, if a transaction is marked for rollback, the enlist() method in TxConnectionEventListener catches a RollbackException, and throws a SystemException back to TXConnectionManager ("Could not enlist XAResource!").
The problem seems to be that the database connection associated with this transaction is not being returned into
connection pool. This leads to a "No managed connections available", after a few repetitions of that situation.

I actually do not know exactly how to solve this problem, simply returning the connection with the "kill" - flag seems a little dangerous... Are there any ideas about how to solve this problem ??

Thanks in advance, Tom

[adrian.brock]

I've fixed the leak, thanks for drawing it to my attention.

You shouldn't be attempting to do more work in a transaction
that is (marked) rollbacked.

This kind of thing typically happens when applications attempt
to do the work of the system.

e.g.

try
{
// Do work
}
catch (EJBException e)
{
// Doing work here is bad
}

Even worse is code I've seen:

try
{
// Do work
}
catch (EJBException e)
{
log.warn("Error", e);
// Don't rethrow and try to continue :-(
}

Regards,
Adrian

[moomin]

Hi Adrian,

I have read your reply to Tom at 26 Oct 2003 for the Managed Connections not returned into pool problem, I would like to ask you do your fix included in jboss 3.0.8?

Thanks

Moomin

29 Dec 2003

[adrian.brock]

No, 3.2.3

Regards,
Adrian

[moomin]

Dear Adrian,

Thank you for your prompt reply.

As I encounter this problem at my customer production site, we need to perform SIT and UAT for the upgrading the JBoss application from 3.0.X to 3.2.X. Thus, I would like to ask it is possible to put the fix on Jboss 3.0.x.

Regards,
Moomin

[adrian.brock]

This is the bug fix. The 3.0 implementation is different to the 3.2 implementation.

You will have to apply it to the LocalTxConnectionManager and the XATxConnectionMananger
depending upon which you using.

http://cvs.sourceforge.net/viewcvs.py/jboss/jbosscx/src/main/org/jboss/resource/connectionmanager/TxConnectionManager.java?r1=1.15&r2=1.16

Regards,
Adrian