OK - looks like I will have to solve this one myself. Turns out that I needed to specify this additional field in my datasource descriptor (ms-sql.ds). <!-- sql to call to check exiting connection is still ok --> <check-valid-connection-sql>select top 1 name from sysobjects with (nolock)</check-valid-connection-sql> This is apparently called before a pooled connection is used, if it fails (say because the connection is closed!!!!) - then the connection is released and a new one is used. Thus - I can now reset my database server without my JBoss application dying a horrible horrible death. Fantastic! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4039079#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...