I'm using various KnowledgeBase objects in a J2EE environment, using JBoss 4.2 as the application server. Currently, I keep a list of KnowledgeBase objects in a stateless session bean. The thought being that to keep the application scalable, we don't want contention around rule sessions. However, I just heard that KnowledgeBase is thread safe. This would mean that I could instantiate a KnowledgeBase once and have multiple StatelessKnowledgeSessions using it concurrently. Can anyone verify that KnowledgeBase is thread safe for me? Would this technique potentially cause contention on a busy system? Dan -- View this message in context: http://www.nabble.com/KnowledgeBase-threadsafe--tp23324327p23324327.html Sent from the drools - user mailing list archive at Nabble.com.