I just ran another test in which our application connected to a single JBoss Messaging server 10 times, before then introducing the second server. I thought this would get the sequence number that Tim mentioned out of step between the two servers. Sure enough, if I stop the first server our application now fails over to the second server correctly and can send messages. It still takes a little while to failover, due to the exception listener not firing for a while after the connection goes down. Is there any way to make the connection verifier run more frequently? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3984696#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...