In general, your young generation should be 1/4 to 1/3 the size of your heap. I usually also recommend setting the heap min and max to the same size. Considering the size of your heap, a 4 second garbage collection is very normal (I have see 20 seconds with heaps that size). Setting the young generation size should help because then fewer objects will get tenured, which will reduce the number of times a full collection gets run. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3987658#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...