I figured out how to optimize it, though there are race conditions when sharing caches, but the whole thing is full of potential race conditions. :-) I optimized put() by creating a cheap cache of all the dummy nodes created by previous put() operations. This seemed to work well enough to pass all the CacheLoader tests. By the way, to test the darn thing, you have to have an Amazon S3 account. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4127237#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...