"timfox" wrote : I didn't understand your test - it looks weird. Also you're calling commit on a non transacted session... I was calling the commit, just to make sure any pending ACK would be flushed to the server, so this assertion would be valid: | assertEquals(0, getMessageCount(service, ADDRESS.toString())); | But I just removed it now. The test is creating two consumers consumers (consNeverUsed and cons1) before any messages are sent. consNeverUsed should never buffer any messages, and it is actually buffering it. I've tried using windowSize = 0, but createSession was complaining about it. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4221566#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...