According to http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#par_g..., it would appear that you are running too many collections and each collection is not freeing enough heap space. Have you collected GC data and graphed it to see what is happening? See my presentation on that subject for information: http://www.cecmg.de/doc/tagung_2007/agenda07/24-mai/2b3-peter-johnson/ind... Also, I assume you are using JDK 6, if that is not correct, please let me know. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4198967#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...