You would add an @CacheConfig annotation: @org.jboss.ejb3.annotation.CacheConfig (name="sfsb-cache", maxSize=100000, idleTimeoutSeconds=300, removalTimeoutSeconds=0) The maxSize param controls the max number of beans. If you don't configure that, and your bean is @Clustered, per the deploy/ejb3-interceptors-aop.xml I have in my workspace, the following should be added to your bean: @org.jboss.ejb3.annotation.CacheConfig (name="jboss.cache:service=EJB3SFSBClusteredCache", maxSize=100000, idleTimeoutSeconds=300, removalTimeoutSeconds=0) It already has a maxSize of 100,000 so I'm not sure how you're ending up with only 10,000. I'll poke around. The name="jboss.cache:service=EJB3SFSBClusteredCache" bit needs to be fixed: https://jira.jboss.org/jira/browse/JBAS-6128 . The way StatefulTreeCache uses that value in AS 5 is to drive a lookup in the CacheManager service, deployed via deploy/cluster/jboss-cache-manager.sar. CacheManager is an on-demand factory for JBoss Cache instances. It's maintains a registry of named JBC configurations, and provides caches based on the name. The name here should be "sfsb-cache". The cache manager is configured to understand the old 4.x name "jboss.cache:service=EJB3SFSBClusteredCache" to be an alias for "sfsb-cache". That allows pre-existing code to work. If you actually wanted to play around with the "sfsb-cache" JBC configuration, you could edit deploy/cluster/jboss-cache-manager.sar/META-INF/jboss-cache-configs.xml. But I don't think that's what you are looking for; you don't control things like the max # of beans via JBC configuration; it's via @CacheConfig. Obviously this needs documenting. :( Does the deploy/ejb3-interceptors-aop.xml file on your JBoss install include this? <annotation expr=&quot;!class((a)org.jboss.ejb3.annotation.CacheConfig) AND class((a)org.jboss.ejb3.annotation.Clustered)&quot;&gt; | @org.jboss.ejb3.annotation.CacheConfig (name="jboss.cache:service=EJB3SFSBClusteredCache", maxSize=100000, idleTimeoutSeconds=300, removalTimeoutSeconds=0) | </annotation> | If your maxSize value were something different, that would explain it. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4184011#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...