We have application working well in JBOSS 4.0.5GA. After moving to jboss 5.0.1GA, we have to use XA datasources. We setup three mysql XA datasources in our application using hiberhate. Each datasource has the following: <track-connection-by-tx>true</track-connection-by-tx> <new-connection-sql>set autocommit=1</new-connection-sql> <no-tx-separate-pools>true</no-tx-separate-pools> My question is: set automcommit=1, for performing a number of entity updates, are they in one transaction? for autocommit, mysql will commit each update immediately. If <new-connection-sql>set autocommit=1</new-connection-sql> is removed from datasource configuration, we will get the following error: MysqlXAException: XAER_OUTSIDE: Some work is done outside global transaction Thanks for help. Dave View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4228145#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...