Shunning and the exception sound like two symptoms of the same problem -- a machine that's overtaxed. Preventing shunning doesn't solve the underlying problem. Your FD protocol has a very short timeout/max_tries combination. With that, a busy machine that takes a while to respond to a heartbeat (perhaps just due to a long garbage collection) will get suspected. The default recommendation for FD now is timeout="10000" max_tries="5". What's your SyncReplTimeout setting? Bumping it up will help prevent the exception. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3982832#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...