Hi, thanks for the suggestions, I've had to roll back to 1.0.1 SP4 as this is a productions server, so I can't diagnose further at this point. Before I rolled back I tried lsof whilst I was getting the error and it was reporting between 5000-7000 handles, the rolled back system is currently reporting around 2000. I didn't get chance to try netstat. I'm not happy about increasing ulimit, I think it's asking for trouble isn't it? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4040112#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...