That is why I place all my data into their own Fqn. I have 1,000,000 objects (Meters) and each of them is constructed using: Fqn fqn = new Fqn("root", "MeterID" + i); Node<Object,Object> node = rootNode.addChild(fqn); node.put("data", meter); Does it mean I *over* do it? Instead of using a sunshine structure (1 level), should I structure my objects to fit into something like radix-tree? The reason I'm using REPL_SYNC is to be fair to EHCache since I'm using SYNC, too, as well as Terracotta (write-lock). Thanks for the quick response :) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4166036#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...