Assuming you meant it had to wait for the backlog of commands on the connection to be processed rather than completions, then a couple of observations. I notice you have sync on persistent set to true on server, but set to false on the connection factory. I'm not sure if that makes sense (it might cause backlogs), perhaps we should disallow that combination. What happens if you have sync on send set on the session factory too? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4194273#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...