anonymous wrote : Yes. The default attribute map is a synchronized hash map because concurrent hash map consumes more memory as the number of the connections grows. Is it really relevant? It will just provide partitioned almost empty HashMaps to avoid the concurrency on a single object. And.. isn't this synchronization limiting the number of connection you can reach up to as it is a contention point? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4149790#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...