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

[Bojan Janisch]

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