Hi, I'm having some trouble trying to maximise JMS throughput using JBoss. I've tried using both JBossMQ and activeMQ within JBoss AS 4.0.5. I am using EJB3. I read the JBoss wiki page on configuring MDBs: http://wiki.jboss.org/wiki/Wiki.jsp?page=ConfigJBossMDB There is an interesting comment in 'general pooling notes': 'In most use cases (common configurations) the delivery server session pool (15 concurrent strictly pooled sessions/threads) throttles the MDB pool (100 instances non strictly pooled) making it irrelevant.' I think this may relate to my problem, but I confess I don't know exactly what is meant by 'delivery server session pool'. I'm firing large numbers of messages from several clients and many threads to a queue on my server. I only ever seem to have about 20 MDBs processing the messages. I think my throughput would increase if I had more MDBs in the pool, but I can't figure out how to increase this. - How do I increase the number of pooled MDBs? - Is my MDB pool size not growing because the delivery server session pool is throttling it? I'm not sure what the delivery server session pool is or how to increase it; is this referring to the <tx-connection-factory> configuration in my *-jms-ds.xml? Thanks, Peter View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4025463#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...