That was too vague and confusing. What do you mean by "response times are slow consistently after we increase the load" That is exactly what I would suspect would happen - the higher the load the slower the response times. And response times for what - the JNDI lookup only or for sending the messages? It is especially confusing when you then say "And only lookup that slows down is looking up queue destination". Are you saying that the response time for sending a message, or the whole processing of a message, is acceptable? Are you saying that only one particular queue has this issue? Are you saying that looking up a topic destination does not have this issue? Are you saying that the response time for looking up the connection factory is acceptable but the response time for looking up the queue is not? Please be very specific and supply numbers, including information about the load. And it still could be GC. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4232007#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...