[rules-users] Help with troubleshooting rules/Drools

[Wolfgang Laun]

Good diagnostics is provided if you follow
http://members.inode.at/w.laun/drools/CustomConsequenceExceptionHandlingHowTo.htmlwhich
has been incorporated into 5.3.0.
-W

On 31 October 2011 23:47, Robert Crawford <crawford at kloognome.com> wrote:

> Any advice on how to troubleshoot problems? I have a fairly simple set of
> rules (a couple dozen), but keep having problems with fatal exceptions. The
> most recent was:
>
> org.drools.RuntimeDroolsException: Unexpected exception executing action
> org.drools.reteoo.PropagationQueuingNode$PropagateAction at 1e60aa7
>     at
>
> org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:977)
>     at
> org.drools.common.DefaultAgenda.fireUntilHalt(DefaultAgenda.java:1231)
>     at
>
> org.drools.common.AbstractWorkingMemory.fireUntilHalt(AbstractWorkingMemory.java:753)
>     at
>
> org.drools.common.AbstractWorkingMemory.fireUntilHalt(AbstractWorkingMemory.java:729)
>     at
>
> org.drools.impl.StatefulKnowledgeSessionImpl.fireUntilHalt(StatefulKnowledgeSessionImpl.java:234)
>     at
> com.kroger.tempmonitor.app.service.RuleService$1.run(RuleService.java:214)
>     at java.lang.Thread.run(Thread.java:662)
> Caused by: java.util.NoSuchElementException
>     at java.util.LinkedList.remove(LinkedList.java:788)
>     at java.util.LinkedList.removeFirst(LinkedList.java:134)
>     at
>
> org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:264)
>     at
>
> org.drools.reteoo.PropagationQueuingNode$AssertAction.execute(PropagationQueuingNode.java:357)
>     at
>
> org.drools.reteoo.PropagationQueuingNode.propagateActions(PropagationQueuingNode.java:238)
>     at
>
> org.drools.reteoo.PropagationQueuingNode$PropagateAction.execute(PropagationQueuingNode.java:502)
>     at
>
> org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:975)
>     ... 6 more
>
>
> No mention of a rule name, so where do I begin?
>
> My architecture is simple: one thread ran fireUntilHalt(), other (multiple)
> threads inserting objects. Should I synchronize on the session so only one
> thread is inserting at a time?
>
> There's one rule that triggers a large number of inserts, and it used to
> give me problems, but I've moved those inserts into Commands and those
> problems seem to have gone away.
>
> Any advice would be welcome, no matter how basic you think it is! Thanks!
>
>
> --
> View this message in context:
> http://drools.46999.n3.nabble.com/Help-with-troubleshooting-rules-Drools-tp3469285p3469285.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
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>
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