If you have one machine hosting the MDBs and another hosting JBM, then it looks like clustering is not useful to you. Are you running clustered or non clustered? To find this out, look in your jboss-messaging.sar directory. There will be a file there called something-persistence-service.xml. If you're file starts with "clustered" then you are running clustered. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4045827#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...