[rules-users] Getting infinite loops even with limitation of fires

Tue Jul 16 11:38:53 EDT 2013

> So you are saying that repeated runs with the same data livelock
somewhere in a rule's RHS but always in a different one?

Yeah there isn't a specific constellation of conditions, but the conclusion is always the same.
And it works if I run the rule separately, only getting this random occurrence in my
multi-threaded environment.

> Do the thread dumps have something in common, e.g., calls to some
org.drools.util.CompositeClassLoader method?

Well the thread dumps looks always exactly the same (except for the rule name). 
So it's always the same code part I think, which causes the spinlock. 

-B

----- Ursprüngliche Mail -----
Von: "Wolfgang Laun" <wolfgang.laun at gmail.com>
An: "Rules Users List" <rules-users at lists.jboss.org>
Gesendet: Dienstag, 16. Juli 2013 16:59:11
Betreff: Re: [rules-users] Getting infinite loops even with limitation of	fires

So you are saying that repeated runs with the same data livelock
somewhere in a rule's RHS but always in a different one? Do the thread
dumps have something in common, e.g., calls to some
org.drools.util.CompositeClassLoader method? (There was an issue with
class loading but I can't remember the details or version.)

-W

On 16/07/2013, Bojan Janisch <bojan.janisch at scai.fraunhofer.de> wrote:
> Hey Wolfgang,
>
> I thinks it's an infinite loop because the thread dump is always the same,
> doesn't matter when I look. The thread is running, not waiting or blocked
> which means that there has to be a spinlock that keeps the thread at the
> current position. And because this thing runs for almost 1 hour now I think
> it is an infinite loop.
>
> Do you have another idea why a thread should run for an endless time always
> at the same code segment if not because of an infinite loop?
>
> Greetings
>
> Bojan
>
> ----- Ursprüngliche Mail -----
> Von: "Wolfgang Laun" <wolfgang.laun at gmail.com>
> An: "Rules Users List" <rules-users at lists.jboss.org>
> Gesendet: Dienstag, 16. Juli 2013 11:55:48
> Betreff: Re: [rules-users] Getting infinite loops even with limitation
> of	fires
>
> Running longer than expected may not be due to overshooting the limit
> for fired rules. Monitoring firings using a listener and registering
> and counting where what actually happens is paramount.
>
> How do you determine that there is in endless loop?
>
> -W
>
> On 16/07/2013, Bojan Janisch <bojan.janisch at scai.fraunhofer.de> wrote:
>> Hello everyone,
>>
>> Recently I'm using Drools in a multithreaded environment. But after a
>> while
>> I see that Drools is running for endless time even though I gave him with
>> fireAllRules(1000) a limitation to fire only 1000 rules. The occurrence is
>> rule-independent, I've checked multiple times and each time it's another
>> rule which works well if I run it separately.
>>
>> Could someone check the code of this stack trace? That's a thread dump of
>> my
>> last run.
>>
>> "ECJ Evaluation Thread 9" daemon prio=10 tid=0x00002b08a4fd9000 nid=0x2f90
>> runnable [0x00002b08a9a82000]
>>    java.lang.Thread.State: RUNNABLE
>> 	at java.util.HashMap.getEntry(HashMap.java:347)
>> 	at java.util.HashMap.containsKey(HashMap.java:335)
>> 	at
>> org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:244)
>> 	at
>> org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:237)
>> 	at
>> org.drools.util.CompositeClassLoader.loadClass(CompositeClassLoader.java:88)
>> 	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
>> 	at
>> defaultpkg.Rule_308_7dd58592a49c4dd1a6fd98dc64c74466DefaultConsequenceInvokerGenerated.evaluate(Unknown
>> Source)
>> 	at
>> defaultpkg.Rule_308_7dd58592a49c4dd1a6fd98dc64c74466DefaultConsequenceInvoker.evaluate(Unknown
>> Source)
>> 	at
>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287)
>> 	- locked <0x000000020865c080> (a org.drools.common.DefaultAgenda)
>> 	at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1221)
>> 	at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1456)
>> 	at
>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710)
>> 	at
>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:679)
>> 	at
>> org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:234)
>> 	at rulevolution.RulEvolution.runDrools(RulEvolution.java:348)
>> 	at rulevolution.RulEvolution.evaluate(RulEvolution.java:183)
>> 	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:
>> 	- None
>>
>> Also here the rule and code snipped I'm using to prove that the infinite
>> loop does not come from my code:
>>
>> //kSession is a StatefulKnowledgeSession
>> try {
>> 	//Limiting the Activation will prevent infinite loops
>> 	kSession.fireAllRules(1000);
>> } catch (Exception e) {
>> 	System.out.println("error while processing :: " + e.toString());
>> 	System.out.println(rule);
>> } finally {
>> 	kSession.dispose();
>> }
>> -------------------------------------------------------------------
>> rule "308"
>> no-loop
>> when
>>
>> $0:NormalizedNamedEntity(
>> ct_0:CoveredText,
>> cp_0:Concept,
>> label_0:getConcept().getPrefLabel().value,
>> getConcept().identifierSource.toLowerCase.contains("ops"))
>>
>> $1:NormalizedNamedEntity(
>> ct_1:CoveredText,
>> cp_1:Concept,
>> label_1:getConcept().getPrefLabel().value,
>> getConcept().identifierSource.toLowerCase.contains("bodyside"))
>>
>> then
>> int start = getStart($0,$1);
>> int ende = getStop($0,$1);
>> String attribute = label_0+" "+label_1;
>> insert(annotate(aJCas, "Operation", 309, attribute, start, ende, "",
>> attribute));
>> end
>>
>> I appreciate any help to solve this occurrence.
>>
>> Greetings
>>
>> Bojan
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
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