Hi Ingomar, Which drools version are you using? We made improvements on 4.0.4, that fixes concurrency issues on mvel core, so if you aren't using it please do an update and try test against your environment. Please let me know if your problems go away when you upgrade. Thanks On Jan 22, 2008 11:13 AM, Ingomar Otter <ingomar.otter(a)valtech.de <mailto:ingomar.otter@valtech.de>> wrote: Folks, I am currently trying to scale our implementation by farming out request into mutliple threads. I am on a 4 CPU Mac. A few things I am wondering about: 1. Although I see an increase in CPU load when going from single to multi-threaded processing the throughput increased marginally. I am pretty sure that my measurements are correct. I have checked the GC and this is not the source of congestion. My question here is whether Drools is using lot's of synchronization that may explain this. 2. When I share the RuleBase accross threads (which I think is valid?) I get interesting errors during execution. eg: org.drools.RuntimeDroolsException : Exception executing predicate org.drools.base.mvel.MVELPredicateExpression@bb981e atorg.drools.rule.PredicateConstraint.isAllowedCachedRight( PredicateConstraint.java:246) at org.drools.common.TripleBetaConstraints.isAllowedCachedRight(TripleBetaConstraints.java:200) atorg.drools.reteoo.JoinNode.assertObject(JoinNode.java:150) atorg.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:318) atorg.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:153) at org.drools.reteoo.Rete.assertObject(Rete.java:175) atorg.drools.reteoo.ReteooRuleBase.assertObject (ReteooRuleBase.java:192) at org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:71) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:909) atorg.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:881) atorg.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:682) atxxxx.DroolsPD.validate(DroolsPD.java:66) at xxxx.DroolsMTRunner.run(DroolsMTRunner.java:30) at java.lang.Thread.run(Thread.java:552) Caused by: org.mvel.CompileException: cannot invoke getter: getSAClass [declr.class: xxx.AbstractSA; act.class: null] atorg.mvel.optimizers.impl.refl.GetterAccessor.getValue( GetterAccessor.java:52) at org.mvel.optimizers.impl.refl.VariableAccessor.getValue(VariableAccessor.java:39) at org.mvel.ast.VariableDeepPropertyNode.getReducedValueAccelerated(VariableDeepPropertyNode.java:22) atorg.mvel.ast.PropertyASTNode.getReducedValueAccelerated(PropertyASTNode.java:21) at org.mvel.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:21) at org.mvel.MVELRuntime.execute(MVELRuntime.java:88) at org.mvel.CompiledExpression.getValue(CompiledExpression.java:111) atorg.mvel.MVEL.executeExpression(MVEL.java:235) at org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpression.java:36) atorg.drools.rule.PredicateConstraint.isAllowedCachedRight(PredicateConstraint.java:240) ... 13 more Caused by: java.lang.NullPointerException atsun.reflect.GeneratedMethodAccessor6.invoke (Unknown Source) atsun.reflect.DelegatingMethodAccessorImpl.invoke( DelegatingMethodAccessorImpl.java:25) atjava.lang.reflect.Method.invoke( Method.java:324) at org.mvel.optimizers.impl.refl.GetterAccessor.getValue(GetterAccessor.java:42) ... 22 more Details: * I use StatelessSessions which are private to the threads * No data is shared between threads (with the exception of the RuleBase, as outline above) * I am on JDK 1.5 I would be grateful for any pointers for 'correct' use of Drools in an MT environment. Cheers, Ingomar Ingomar Otter Chief Technology Officer ingomar.otter(a)valtech.de <mailto:ingomar.otter@valtech.de> Mobile: +49 172 2367867 Valtech GmbH Bahnstraße 16 40212 Düsseldorf Germany Phone: +49 (0)211 179237-0 Fax: +49 211 179237-19 www.valtech.de <http://www.valtech.de/> Geschäftsführer: Ingo Kriescher Amtsgericht Düsseldorf HRB48672 _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/rules-users -- Fernando Meyer http://fmeyer.org JBoss Rules Core Developer fernando(a)fmeyer.org <mailto:fernando@fmeyer.org> ------------------------------------------------------------------------ _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users