Likely, nobody including the devs have tested 200 separate cache instances versus a cache with 200 regions. Given that there are limitations on what you can do within a region, specifically you can't configure a per-region cache loader yet, you would need separate cache instances. I can't see anything wrong with 200 cache instances, just potential headaches with dealing with configuration. You do lose a bit of efficiency, in terms of memory. What might be a good compromise would be to create about 10 different "flavors" of caches and share these amongst the 200 applications. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4045338#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...