@roschmel: Okay, now its a bit clearer. Why don't you use hibernate pessimistic locking in this case? And: With async=true, couldn't you get completly rid of the problematic situations if you use it often enough? Alex wrote : An ExecuteJobsCommand is constructed with the exclusive job IDs and sent to the command queue. The command executor then executes the jobs serially. Couldn't this lead to the behavior of a repeating timer creating jobs which cannot be processed as fast as created (assume the system is very utilized)? This is why we normally decided against executing timer stuff over JMS. Or what do you think? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4208876#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...