If you take a couple more thread dumps, are the -3 and -14 threads progressing? Also, what does com.tracker.web.servlet.SessionCounter.sessionCreated do? Obviously it's updating a java.util.HashMap. Is it doing anything to synchronize access to that non-thread-safe object? Perhaps a ConcurrentHashMap is a better choice, since you can concurrently get the sessionCreated callback from multiple threads. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4121077#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...