What is client application trying to do? Especially, what's the purpose of using ctx.rebind("java:MySQLDS", ref); View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4112924#4112924 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4112924