Hello, I have reached this post because I am facing the same problem. I see that in the FAQ it says: anonymous wrote : Q: I have strange pooling? Connections that are not matched in my | | matchManagedConnections | | are destroyed. | | A: Yes this is the default/expected behaviour. I have had a look at the jca 1.5 specification and according to this issue it says the following anonymous wrote : If the resource adapter cannot find an acceptable ManagedConnection instance, it | returns a null value. In this case, the application server requests the resource | adapter to create a new connection instance. So, it does not say anything in particular about this behaviour. Now I'm gonna explain my use case, on which I consider this is not the expected behaviour: My resource adapter holds connections, each one have an associated window, so that on a request, and identifier is stored on the window to be removed later when an ACK is received. When a request is made, it may need one or more slots on the window, so I specify a ConnectionRequestInfo with the number of slots needed. Suppose a request is made which needs 2 slots, and all connections in the pool have 1 free slot. The matchManagedConnections method returns null and application server creates a new Connection that is returned. At this moment, if existing connections are destroyed, their associated window information and actions on ACKs are lost. Other reason for not destroy them is that as they all have 1 slot free, they should be available for other 1 slot requests. Also, they will become available as ACKs come. I have seen that using <application-managed-security/> not only changes this behaviour, as application must implement all connection pooling task. In my case a new connection is created on each request, so I suppose that no connection management is performed by jboss. In my opinion, I consider that this behaviour should be configurable on a policy property, so you can use all jboss services in your resource adapter as matchManagedConnections method and choose what to do with no matching connections. I only want to explain my point of view in order to contribute on improving this amazing project. Thanks a lot! Borja View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4165307#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...