I see. One question on fault-tolerange to message loss. Do the messages get replicated across the cluster (using post-office pulling or post-office routing?), so in case a node fails, they are not lost OR are they stored in a database until acknowledged? If it's the database, then I can assume that not persisted messages are lost in case of node failure. If it's replication, how does it affect the performance in term of network traffic/resource usage? Are all the messages forwarded/pulled by all the members or only those unread for a # of milliseconds and only a limited number of nodes? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4104305#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...