anonymous wrote : I am not quite sure how reliable message delivery (PERSISTENT) is implemented in JBoss Messaging. Assuming a JDBC persistence manager, does the AUTO_ACK mode result in a JDBC commit after each message ? JBossMessaging is very reliable, it is 100% Sun CTS (Compatibility Test Suite) JMS and JEE (1.4 and 5) compliant. persistence is guaranteed as per the JMS specification. Which database were you using, remember hsql, the default database, is in memory and doesnt actually persist! You will need to use a full database such as Oracle or MySQL. On my tests, persistent auto-ack send was too fast ( about 3000 1K messages/s) which means that there is no auto commit. if so, it would mean that persistent message delivery is not really reliable which is a violation of the JMS spec. What is your topology, are you using a queue or a topic, remember messages sent to a topic with a nondurable subscriber wont be persisted. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4128269#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...