The jms-ds.xml file is one of the configuration files that comes with JBoss Messaging when using in AS 4.2.x. Based on the error message, there must be another configuration file that contains the MBean jboss.messaging:service=ServerSessionPoolMBean,name=StdJMSPool. Could you do a text search of all *.xml files in server/jms for that MBean? Also, could you post the contents of the *-ds.xml file you created for MySQL? When you do that, make sure you enclose the XML text within code brackets (select the text and click the Code button above the editor window). Also, click Preview to ensure that the text is formatted correctly before clicking Submit. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4174411#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...