Hi all

I  have encountered an issue when Droools fusion is run in the stream mode with 'multithreadEvaluation' and  maxThreads=5.   The issue is as follows.

org.drools.
RuntimeDroolsException: Unexpected exception executing action org.drools.reteoo.PropagationQueuingNode$PropagateAction@8c1400
    at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1549)
    at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:160)
    at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:121)
    at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:80)
    at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:28)
   .........
Caused by: org.drools.RuntimeDroolsException: java.lang.NullPointerException
    at org.drools.rule.Accumulate.accumulate(Accumulate.java:172)
    at org.drools.reteoo.AccumulateNode.modifyTuple(AccumulateNode.java:424)
    at org.drools.reteoo.AccumulateNode.assertObject(AccumulateNode.java:284)
    at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:42)
    at org.drools.reteoo.PropagationQueuingNode$AssertAction.execute(PropagationQueuingNode.java:326)
    at org.drools.reteoo.PropagationQueuingNode.propagateActions(PropagationQueuingNode.java:221)
    at org.drools.reteoo.PropagationQueuingNode$PropagateAction.execute(PropagationQueuingNode.java:394)
    at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1547)
    ... 18 more
Caused by: java.lang.NullPointerException
    at org.drools.base.accumulators.MVELAccumulatorFunctionExecutor.accumulate(MVELAccumulatorFunctionExecutor.java:129)
    at org.drools.rule.Accumulate.accumulate(Accumulate.java:164)
    ... 25 more


Then NPE is due to the argument  'context' of the accumulate is null.

When I  run the fusion in the same scenario without  'multithreadEvaluation' , it works fine.  

Could someone help me to identify the actual issue?

Thanks Lots

Indika

Please Note : I did not inject events concurrently.  But , I need to do that too