Hello! I am researching how to do thread safe update of packages/rules in a rulebase. I noticed that there are lock() and unlock() methods on the RuleBase object, but could not find much documentation on how they could be used. I am trying to implement the following scenario and was wondering if someone could verify that I am using the lock functionality correctly in this case: Thread1: 1. rulebase.getStatelessSession() 1.1 rulebase.lock() 1.2 rulebase.removeRule(rule1) 1.3 rulebase.removePackage(somePackage) 1.4 rulebase.addPackage(someCompiledNewPackage) 1.5 rulebase.unlock() Thread2 2. rulebase.getStatelessSession() Threads 1 and 2 use the same rulebase object. Quesion 1: What does it mean having the rulebase be locked in Thread1? Does it mean, that if Thread2 is trying to get the session , say, between steps1.2 and 1.3 of the Thread1 , then it will wait until Thread1 released the lock on the rulebase? If that's true, that's exactly what I need. Question 2: I also see methods rulebase.getAdditionsSinceLock() and getRemovalsSinceLock(). Who will see anything when calling these functions - Thread1 after operation 1.5? before 1.5? Or Thread2? But, which lock would it mean to Thread2? - it woudl probably not even be aware of any locks being place by other threads?? Thanks! Marina