[rules-users] Getting deadlock-like thread state
Hey drools users,
I'm running drools multiple times in parallel with ECJ (genetic algorithm framework).
Also I'm running ECJ multiple times in parallel (evaluation purpose).
But each time I want to run ECJ, after an unspecific time, one thread is running infinite
long while ECJ waits for it to finish. Additionally to this my
working memory is steadily growing while hanging in this deadlock-like state, though this
might not be due to drools. This goes on until I get an gc out of
memory exception.
I've created a threaddump which always looks so:
java.lang.Thread.State: RUNNABLE
at java.lang.Object.notifyAll(Native Method)
at org.drools.common.DefaultAgenda.notifyHalt(DefaultAgenda.java:1478)
- locked <0x00002af5f3b0fe88> (a java.util.concurrent.atomic.AtomicBoolean)
at org.drools.common.DefaultAgenda.addActivation(DefaultAgenda.java:466)
at org.drools.common.DefaultAgenda.addActivation(DefaultAgenda.java:326)
at org.drools.reteoo.RuleTerminalNode.assertLeftTuple(RuleTerminalNode.java:259)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:196)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:71)
at org.drools.reteoo.JoinNode.propagateFromLeft(JoinNode.java:107)
at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:95)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:196)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:71)
at org.drools.reteoo.JoinNode.propagateFromLeft(JoinNode.java:107)
at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:95)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:196)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:71)
at org.drools.reteoo.JoinNode.propagateFromRight(JoinNode.java:159)
at org.drools.reteoo.JoinNode.assertObject(JoinNode.java:148)
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.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:903)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:847)
at
org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:269)
at rulevolution.RulEvolution.runDrools(RulEvolution.java:343)
at rulevolution.RulEvolution.evaluate(RulEvolution.java:185)
at ec.simple.SimpleEvaluator.evalPopChunk(SimpleEvaluator.java:259)
at ec.simple.SimpleEvaluator$SimpleEvaluatorThreadCG.run(SimpleEvaluator.java:341)
at ec.util.ThreadPool$PoolThread.run(ThreadPool.java:57)
Locked ownable synchronizers:
- <0x00002af5f3ae95d0> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
To my Programm:
Rules are generated in parallel and for each rule, a new KnowledgeBase, KnowledgeBuilder
and StatefulKnowledgeSession is created.
Objects are inserted into the session and the rule is fired. The session will be disposed
after no facts matches my rule or 1000
conclusions are fired.
I've searched the net for a similar problem, but with no success. Does someone know
why Drools get into such a thread state and
how to get out of it?
I appreciate any help.
Bojan