You can find out what the app server is doing at any point in time by taking a thread dump and examining the stack trace for each thread. As far as memory is concerned, what you are noticing does not strike me as an issue - a single request that allocates a lot of objects, such as for a daily/weekly/monthly report, can cause such a spike in memory usage. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4235032#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...