Thank you for your help. I have another question. If a ManagedConnection is used by connection, Can this ManagedConnection be matched with a new connecion? If so, I have the following question: If one connection "A" get a ManagedConnection from pool which is used by another connection "B". After the first one "A" finished and want to close, dose it have some effection to connection "B"? for example, if "A" invokes "close()", the ManagedConnection will invoke the "cleanup()" function, does it effect the connection "B"? Is the ManagedConnection pushed into pool before the "A" finished ? The second question is why jobss service does't invoke "mathManagedConnection()" which is implemented in MyManagecConnectionFactory? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4096071#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...