Looks like you have a memory leak - look at the heap size after each GC. Also, with setting the young gen to 400M, you will end up running a major collection if you have more that around 600MB heap in use - once you crossed that magic barrier you get nothing but full GCs. You will need to monitor the heap usage. Try using the jmap and jhat utilities that come with the JDK. Also, VisualVM that comes with JDK 6 has some great tools for finding memory leaks - I know that VisualVM can monitor apps running with JDK 5 but I don't recall if will do heap usage analysis for JDK 5. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4240172#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...