Thanks. So, the eviction queue should not be the cause of our problem as the content in the queue is pretty small. I think we have found out the problem we had in production. It is the hot deployment. I know jboss does not recommend redeployment in production, we use it once in a while to add new datasources. What happened in our case is like this: We turned on hot deployment for adding a new datasource. But we also changed the treecache.xml so that the Max node number can be reduced. When the hot deployment runs, it redeployed treecache. Also, we have hibernate session factory service (mbean) depends on the treecache mbean. So all the session factories got redeployed. At that moment, jboss was hosed and refused to take in requests. What we do not know is that what happens in hot deployment of treecache with actively being used by hibernate. Does this explain why our eviction queue got so big? Thanks. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4224149#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...