thanks for the answer. here are my questions again: 1. are you talking about DeliveryMode.PERSISTENT ? if I choose to use database persistence, why do I still have to set this property? as mentioned in your last post, it will get lost if it has not been paged to database yet, if I don't set it to persistent mode. 2. if I set the message to be DeliveryMode.PERSISTENT, and messages have not been paged to database, the server gets restarted, how does it handle the recovery? backed by disk file? 3. the message dequeue is fast, but the message enqueue is really slow compared to oracle AQ. any way, I can tune the enqueue performance? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4165223#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...