Clebert had the idea of a user being able to batch the delivery of transactions to MDB's. Say the tx batch size was 10 and the tx was rolled back for some reason on the 9th message the all the previous 8 messages would also be rolled back. i'm not sure of the best way to do this tho, because of the following reason. currently there are more than one sessions feeding the MDB's, i think the default is 15 sessions each with a single consumer. This would mean that if each session was batched individually you would get a weird order of messages if say one session was rolled back, i.e. this session may be consuming messages 1,10, 20 etc. Specifying only 1 session would solve this but would slow things down under heavy load. alternatively we could enlist all the sessions with the same tx but this would mean extra synchronization and would also slow things down. any ideas anyone? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4247523#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...