"kvbisme" wrote : What is confusing to me is that Machine1 is the first machine in the cluster so I am confused what would cause Machine1 to become unresponsive to itself? It isn't unresponsive to itself, it's unresponsive to other members in the cluster. They decide to remove Machine1 from the group. anonymous wrote : Is there a particular fix I can point to in JGroups for justification of this upgrade to the boss? Can't recall anything specific, no. I have an (admittedly vague) memory of a similar issue coming up sometime in the past and moving off of JGroups 2.2.7 helped. In general, using JGroups 2.4 is recommended. 2.2.7 is very old. We were forced for policy reasons to leave it in all the 4.0.x releases (so for example a 4.0.5 server could interoperate with a 4.0.2). But if it weren't for that requirement, we would have used a much later JGroups release in AS 4.0.5. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4137922#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...