I don't have any specific log categories, no, as without more information on what's increasing in the heap there's not much to go on. When n1 is shut down, n2 starts getting failover requests and starts doing twice as much work, so memory increase is expected. Perhaps the increase would be a bit more than you'd expect, as a session that is being actively handled on a node takes ~ 2x the memory of one that is just being stored as a backup for another node. (That BTW is not the case in JBoss 5.) But whether that's the problem, or it's just that n2 is now doing n1's work, or if it's some bug, there's not enough information to say. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4258250#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...