This i certainly not a JBoss clustering issue...but...the last time I used oracle in that mode, you had to use the Type 2 Driver. Hope this helps. Think of it this way. One of these has to be true. 1)Type 4- The IP of the database never changes even after Oracle's failover occurs. 2)Type 2 - The Oracle SID never changes (which it doesnt, but the Oracle CLI driver handles pointing the SID to the new IP address after Oracle fails). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4029347#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...