Did you ever resolve this issue? I'm experiencing similar problems. I see the hsqldb data file growing to +400MB and a periodic action occurring in hsqldb that seems to gobble up the resources so nothing happens. Everything then times-out. Is this a known issue with hsqldb under load? At this point I'm considering replacing it. Have also found some posts stating it is a good idea to replace. Thanks View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3976980#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...