Timer of BisocketServerInvoker is a static object. When BisocketServerInvoker start, it will create a controlMonitorTimerTask and insert it to Timer. Then BisocketServerInvoker cleanup, it will call controlMonitorTimerTask's shutdown method which will set its status to CANCELLED. Thus, controlMonitorTimerTask will still has its reference in static Timer, even its status is CANCELLED after BisocketServerInvoker destory. So Timer's size will increase until jboss crash, right? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4160420#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...