NameNotFound is understandable since JBossMQ is deployed as singleton and I bet this exception happens on the Node that does not have JBossMQ started. If you were to look at the JndiView (via JMX console) you won't find any Queues and/or Topics deployed. In oher words it is expected result if. . . JNDI "autodiscovery" disabled, some other jndi properties changed and so on... Autodiscover feature that is a part of JBoss clustered JNDI lookup should make an attempt to find a node in the cluster which is able to serve such JNDI request if initial lookup failed. . . before NameNotFound is thrown Did you change anything in jndi.properties file? Could you post a code snippet how the lookup is made? Are you passing a specific properties to the InitialContext? and I assume queues and topics are deployed and started on the Master node (the one that is currently running JBossMQ) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3984996#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...