The set of GC output you posted at 9:37 looks good. Earlier, all of your GCs were full GCs taking around 10 seconds. Now you have minor GCs taking less than 1/10th of a second. Your post at 10:02 shows that you have overrun the 5GB heap you set. Note the heap sizes both before and after the collection are around 5GB. Now you have to find out why the amount of heap in use jumped from 2.5GB in the 9:37 posting to 5GB in the 10:02 posting. Look at the GC outputs for where the heap sizes started to increase and find out what was going on at that time. If the increase is a jump, then something changed, find out what it was. If the increase was gradual, I would suspect a memory leak. Add -XX:+PrintGCTimestamps to the JVM options - this will let you know when each GC was done (amount of time since the app started). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4137815#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...