Thank you for reply. Two days ago I set logging level for org.jgroups to INFO (previously it was WARN), and the problem magically disappeared - I still can't reproduce it. Now it says "created socket to ..." on the new node and "input_cookie is bela" on the master node. If it appears again, I will play with logging and TCPPING timeouts. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4025317#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...