I'm trying to stress-test Drools to see what its limits are, and I stumbled across a NPE when I have a large amount of facts in a stateful knowledgebase: java.lang.NullPointerException at org.drools.core.phreak.PhreakTimerNode.doPropagateChildLeftTuple(PhreakTimerNode.java:355) at org.drools.core.phreak.PhreakTimerNode.doPropagateChildLeftTuples(PhreakTimerNode.java:325) at org.drools.core.phreak.PhreakTimerNode.doNode(PhreakTimerNode.java:72) at org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:357) at org.drools.core.phreak.RuleNetworkEvaluator.outerEval(RuleNetworkEvaluator.java:161) at org.drools.core.phreak.RuleNetworkEvaluator.evaluateNetwork(RuleNetworkEvaluator.java:116) at org.drools.core.phreak.RuleExecutor.reEvaluateNetwork(RuleExecutor.java:200) at org.drools.core.phreak.RuleExecutor.evaluateNetworkAndFire(RuleExecutor.java:67) at org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:935) at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1200) at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:957) at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:931) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:256) I have a little program that creates, populates, fires, and destroys a session repeatedly. With 10K objects in the knowledge base, I get the NPE the first time I loop through my program, but not subsequently (probably because by the subsequent executions things have been cached). With 100K objects, I get the exception most times. With 1M objects, I get the NPE every time. Am I doing anything wrong or is it simply taking so long to execute all the rules that something times out? Is there a timeout param I could set? Thank you! Joseph -- View this message in context: http://drools.46999.n3.nabble.com/Null-Pointer-Exception-with-10K-kBase-o... Sent from the Drools: User forum mailing list archive at Nabble.com.