[rules-users] NPE from reteoo.AccumulateNode

First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final The full source code and rules are pasted below but here's the gist, I have a stateful knowledge session to which I am inserting events and running an accumulate on the input events. I have a for loop generating the events and inserting them as rapidly as possible. In the rules I use an accumulator to calculate the average of the values contained within the events. The behavior I'm observing is that if I insert ~120 events without any waiting I receive an NPE. If I Thread.sleep for even just 1ms the test goes off without a hitch. Have I uncovered a bug which should be logged in JIRA? I would check through JIRA to see if something similar has been logged but I'm so unfamiliar with the codebase, not to mention it could all just be user error. The NPE is as follows: Exception in thread "main" java.lang.NullPointerException at org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050) at org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345) at org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259) at org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676) at org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590) at org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350) at org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119) at org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94) at org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167) at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235) at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55) at drools5fusioneval.Average.main(Average.java:66) ### Average.java ### package drools5fusioneval; import java.io.IOException; import java.util.Random; import org.drools.KnowledgeBase; import org.drools.KnowledgeBaseConfiguration; import org.drools.KnowledgeBaseFactory; import org.drools.builder.KnowledgeBuilder; import org.drools.builder.KnowledgeBuilderFactory; import org.drools.builder.ResourceType; import org.drools.conf.EventProcessingOption; import org.drools.io.ResourceFactory; import org.drools.runtime.StatefulKnowledgeSession; import org.drools.runtime.rule.WorkingMemoryEntryPoint; class AvgDFEChannel implements org.drools.runtime.Channel { @Override public void send(Object o) { System.err.println ("Recieved channel message: "+ o); } } public class Average { public static void main(String[] args) throws InterruptedException, IOException { KnowledgeBaseConfiguration kbconfig = KnowledgeBaseFactory.newKnowledgeBaseConfiguration(); kbconfig.setOption(EventProcessingOption.STREAM); KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(kbconfig); KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"), ResourceType.DRL); if (kbuilder.hasErrors()) { System.err.println(kbuilder.getErrors().toString()); } kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); final StatefulKnowledgeSession session = kbase.newStatefulKnowledgeSession(); session.registerChannel("heartbeat", new AvgDFEChannel ()); WorkingMemoryEntryPoint ep01 = session.getWorkingMemoryEntryPoint("ep01"); new Thread() { public void run() { session.fireUntilHalt(); } }.start(); Thread.sleep (5000); // give the engine time to get setup Server hiwaesdk = new Server ("hiwaesdk"); session.insert(hiwaesdk); long LIMIT = 120; Random rnd = new Random (System.nanoTime()); for (long i = LIMIT; i > 0; i--) { int j = rnd.nextInt (212); ep01.insert (new IntEvent (j)); //Thread.sleep (0x1); } System.out.println (hiwaesdk); } } ### average.drl ### package drools5fusioneval declare IntEvent @role ( event ) @expires(15s) end declare Statistics opsec : long total : long end global Statistics stats; rule "Init engine" salience 100 when then stats = new Statistics (); stats.setTotal (0); stats.setOpsec (0); drools.getWorkingMemory ().setGlobal ("stats", stats); System.out.println ("Engine initialized"); end rule "number rule" when $e : IntEvent () from entry-point ep01 $s : Server (hostname == "hiwaesdk") then $s.currentTemp = $e.data; stats.setOpsec (stats.getOpsec () + 1); stats.setTotal (stats.getTotal () + 1); end rule "average temp" when Number ($avg : intValue) from accumulate ( IntEvent ($temp : data) over window:length(10) from entry-point ep01, average ($temp) ) $s : Server (hostname == "hiwaesdk") then $s.avgTemp = $avg; end rule "Heartbeat" timer ( int: 5s 5s) when then channels["heartbeat"].send ("Heartbeat: "+ stats.getOpsec () / 5 +", "+ stats.getTotal ()); stats.setOpsec (0); end -- View this message in context: http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381... 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