anonymous wrote : So 20 messages had been started and of those 5 had been completed If you look at the ejb3-interceptors-aop.xml in the deploy folder, you will notice that for the Message Driven Bean, there's a StrictMaxPool setting of max pool size = 15. Looking at your logs, it appears that each message processing in the onMessage takes around 10 or more minutes. And you have reached a stage where all the pool size of 15 has exhausted for that MDB. You can configure the pool size for your MDB by using a @PoolClass annotation. See this for details http://www.jboss.org/jbossejb3/docs/reference/build/reference/en/html/ses... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4199120#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...