I noticed a change in trunk that switched from the UMDM from HashMap to ConcurrentHashMap. Why was this change made? The design of the UMDM is that writes are confined to single thread on startup, and all access after that point is read-only. Switching from HashMap to ConcurrentHashMap adds unnecessary locking. -Jason View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4013932#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...