Hello, It's very difficult to treproduce as this is a big telecom project - Phonbook3G synchronization - (6 month with 12 people) - each sequencer that use a JMS selector on the shared queue launch a complex SYNCML synchronisation with an external server My idea was just to replace the plumbing because : 1) i found that the persistence implementation in Oracle is costly - and the implementation seems different & optimized with JBossMessaging 2) One key point on JBoss Messaging is the performance improvment My performance test use a home-made injector (due to proprietary protocol). -With JBossMQ i achieve around 2 req/s - With JBossMessaging less than 0,5 req/s ( and i get some timeout ) For information 2req/s means around 50 open session on JBoss. I will try to give you more precise information using OptimizeIt Is it possible that i did some configuration mistakes that could explain this difference ? (I don't see what) rgds, View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3974135#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...