You should not attempt to cache connections. The typical usage pattern is acquire the connection, use the connection, close the connection. JBossJCA 1) Acquire the connection 2) Use the connection 3) Close the connection JBossJCA is telling you two thing with the errror message 1) You are not correctly closing your JDBC connections as a result, JBossJCA is having to close them for you. 2)You are attempting to reuse a connection handle that has already been closed (by JBossJCA). Review your code and make sure it conforms to the above pattern. Note, there is nothing wrong with caching a DataSource as this is just a simple connection factory. However, the connection should be released (closed) after use. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4024958#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...