I should have added that the script still completes successfully, it is only the JIT optimization that is having problems and only when some threshold is reached causing an attempt at performing the optimization - as per descriptions I have read earlier. The problem is that I thought there was a fix already in place for this problem if I read the earlier posts correctly but perhaps I do not know how to enable it. paulk_asert wrote > When I run this Groovy script using drools 5.5.0.CR1 with numAnimals = 8 > and numLegs = 120, it works fine. If I set numAnimals = 17 and numLegs = > 1020 then it fails with a JITting error. I saw a bunch of Jira issues > related to JITting issues but no open ones seemed to match exactly. > > @GrabResolver('https://repository.jboss.org/nexus/content/groups/public-jboss/') > @Grab('org.drools:knowledge-api:5.5.0.CR1') > @Grab('org.drools:drools-compiler:5.5.0.CR1') > @Grab('org.drools:drools-core:5.5.0.CR1') > @Grab('com.sun.xml.bind:jaxb-xjc:2.2.5.jboss-1') > @GrabExclude('com.github.relaxng:relaxngDatatype') > @GrabResolver('http://repo2.maven.org/maven2/') > @Grab('org.mvel#mvel2;2.1.2.Final') > @Grab('org.slf4j#slf4j-simple;1.6.4') > import groovy.transform.Immutable > import static org.drools.KnowledgeBaseFactory.newKnowledgeBase > import static > org.drools.builder.KnowledgeBuilderFactory.newKnowledgeBuilder > import static org.drools.builder.ResourceType.DRL > import static org.drools.io.ResourceFactory.newReaderResource > > def numAnimals = 8 > def numLegs = 120 > def kbuilder = newKnowledgeBuilder() > def drl = ''' > dialect "mvel" > rule "deduce animal counts" > when > $crane : Crane( ) > $centipede : Centipede( ) > $tortoise : Tortoise( > quantity + $crane.quantity + $centipede.quantity == ''' + > numAnimals + ''', > quantity * numLegs + $crane.quantity * $crane.numLegs + > $centipede.quantity * $centipede.numLegs == ''' + numLegs + ''' > ) > then > System.out.println( "Cranes " + $crane.getQuantity() ) > System.out.println( "Tortoises " + $tortoise.getQuantity() ) > System.out.println( "Centipedes " + $centipede.getQuantity() ) > end > ''' > kbuilder.add(newReaderResource(new StringReader(drl)), DRL) > def kbase = newKnowledgeBase() > kbase.addKnowledgePackages(kbuilder.knowledgePackages) > def ksession = kbase.newStatefulKnowledgeSession() > > (numAnimals + 1).times { n -> > if (numLegs.intdiv(Crane.numLegs) >= n) { > ksession.insert(new Crane(n)) > } > if (numLegs.intdiv(Tortoise.numLegs) >= n) { > ksession.insert(new Tortoise(n)) > } > if (numLegs.intdiv(Centipede.numLegs) >= n) { > ksession.insert(new Centipede(n)) > } > } > > ksession.fireAllRules() > ksession.dispose() > > @Immutable > class Crane { > static int numLegs = 2 > int quantity > } > > @Immutable > class Tortoise { > static int numLegs = 4 > int quantity > } > > @Immutable > class Centipede { > static int numLegs = 100 > int quantity > } > > Here is the error message: > > Exception in thread "Thread-1" java.lang.RuntimeException: Exception > jitting: quantity + $crane.quantity + $centipede.quantity == 17 && > quantity * numLegs + $crane.quantity * $crane.numLegs + > $centipede.quantity * $centipede.numLegs == 1020 > at > org.drools.rule.constraint.MvelConstraint.executeJitting(MvelConstraint.java:275) > at > org.drools.rule.constraint.MvelConstraint.access$200(MvelConstraint.java:51) > at > org.drools.rule.constraint.MvelConstraint$ConditionJitter.run(MvelConstraint.java:250) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) > at java.lang.Thread.run(Thread.java:722) > Caused by: java.lang.RuntimeException: java.lang.RuntimeException: Error > writing method evaluate > at > org.drools.rule.builder.dialect.asm.ClassGenerator.newInstance(ClassGenerator.java:200) > at > org.drools.rule.constraint.ASMConditionEvaluatorJitter.jitEvaluator(ASMConditionEvaluatorJitter.java:53) > at > org.drools.rule.constraint.MvelConstraint.executeJitting(MvelConstraint.java:273) > ... 5 more > Caused by: java.lang.RuntimeException: Error writing method evaluate > at > org.drools.rule.builder.dialect.asm.ClassGenerator$MethodDescr.write(ClassGenerator.java:881) > at > org.drools.rule.builder.dialect.asm.ClassGenerator.generateBytecode(ClassGenerator.java:128) > at > org.drools.rule.builder.dialect.asm.ClassGenerator.generateClass(ClassGenerator.java:144) > at > org.drools.rule.builder.dialect.asm.ClassGenerator.newInstance(ClassGenerator.java:198) > ... 7 more > Caused by: java.lang.ArrayIndexOutOfBoundsException: 0 > at org.mvel2.asm.Frame.merge(Frame.java:1373) > at org.mvel2.asm.Frame.merge(Frame.java:1329) > at org.mvel2.asm.MethodWriter.visitMaxs(MethodWriter.java:1282) > at > org.drools.rule.builder.dialect.asm.ClassGenerator$MethodDescr.write(ClassGenerator.java:879) > ... 10 more > > Is this a known issue? > > Thanks, Paul.