XA spec, section 3.3: [quote} RMs in the DTP environment should anticipate that many threads will try to use them concurrently. If multiple threads use an RM on behalf of the same XID, the RM is free to serialise the threads’ work in any way it sees fit. For example, an RM may block a second or subsequent thread while one is active. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217332#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...