There have been many threads (no pun intended) on this in the past; here's one arbitrary example: http://drools-java-rules-engine.46999.n3.nabble.com/KnowledgeBase-threads... However I haven't been able to find a declarative statement anywhere from the Drools developers that says, definitively: Yes, you may call newStatefulSession() and newStatelessSession() on a KnowledgeBase that is shared by many threads without performing synchronization. This is certainly implied. Is it indeed true? Thanks, Laird -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/KnowledgeBase-OK-to-s... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users