Hmmn... You are right this is problematic. Each time when a pojo is attached, a new cache node will be created under __JBossInternal__. So for optimistic locking this will be problem for concurrent transaction. This will evitably create high rate of rollback and degrade the performance. I ahve created a jira: http://jira.jboss.com/jira/browse/JBCACHE-915 A partial workaround is to use "region" in cache such that __JBossInternal__ is separate for each region. However, for concurrent access under the same region, the problem would still exist. Any reason that you must use optimistic locking? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3995547#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...