Hey everyone, I have been running Drools 5.2 for a long time now and decided to try out Drools 5.5 to see what was new. I felt that 5.2 was always a bit of a memory hog so I was hoping that 5.5 would be better, however it seems to have gotten worse. Previously I could run my company's test suite with -Xmx1024m -XX:MaxPermSize=256m. Now I get: [Error: Java heap space] [Near : {... MyDomainObject != CE ....}] ^ [Line: 1, Column: 1] at org.mvel2.compiler.ExpressionCompiler._compile(ExpressionCompiler.java:308) at org.mvel2.compiler.ExpressionCompiler.compile(ExpressionCompiler.java:62) at org.mvel2.MVEL.compileExpression(MVEL.java:810) at org.drools.base.mvel.MVELCompilationUnit.compile(MVELCompilationUnit.java:435) at org.drools.base.mvel.MVELCompilationUnit.getCompiledExpression(MVELCompilationUnit.java:238) at org.drools.rule.constraint.MvelConstraint.createMvelConditionEvaluator(MvelConstraint.java:206) at org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:190) at org.drools.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:157) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:137) at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:141) at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235) at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:903) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:847) at org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:269) at my.company.KnowledgeBaseStatelessRuleEngine.execute(KnowledgeBaseStatelessRuleEngine.java:48) I incrementally increased the max heap size in steps of 500m to see when the heap error would go away and I had to go all the way up to 4000m. Is it common knowledge that Drools requires more memory since 5.5? Is there anything our rules could possibly be doing wrong that the newer versions don't like? Once I do get the tests running, I am getting a lot of errors about a comparison to a string with the value of "null": Exception executing consequence for rule "SomeRule_39" in my.company.user.rules: [Error: incompatible types in statement: class java.lang.String (compared from: class my.company.userdata.intermediate.numbers.TotalScore)] [Near : {... this != "null" ....}] ^ [Line: 1, Column: 1] at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1297) 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:674) at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230) at my.company.commons.rules.util.KnowledgeBaseStatelessRuleEngine.execute(KnowledgeBaseStatelessRuleEngine.java:49) Caused by: [Error: incompatible types in statement: class java.lang.String (compared from: class my.company.userdata.intermediate.numbers.TotalScore)] [Near : {... this != "null" ....}] ^ [Line: 1, Column: 1] at org.mvel2.ast.BinaryOperation.<init>(BinaryOperation.java:84) at org.mvel2.util.CompilerTools.finalizePayload(CompilerTools.java:118) at org.mvel2.compiler.ExpressionCompiler._compile(ExpressionCompiler.java:287) at org.mvel2.compiler.ExpressionCompiler.compile(ExpressionCompiler.java:62) at org.mvel2.MVEL.compileExpression(MVEL.java:810) at org.drools.base.mvel.MVELCompilationUnit.compile(MVELCompilationUnit.java:435) at org.drools.base.mvel.MVELCompilationUnit.getCompiledExpression(MVELCompilationUnit.java:238) at org.drools.rule.constraint.MvelConstraint.createMvelConditionEvaluator(MvelConstraint.java:206) at org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:190) at org.drools.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:157) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:137) at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235) at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:903) at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:192) at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:186) at my.company.user.rules.Rule_SomeRule_39_e811b8e64e174d6b84ff672feb3172d2.defaultConsequence(Rule_SomeRule_39_e811b8e64e174d6b84ff672feb3172d2.java:8) at my.company.user.rules.Rule_SomeRule_39_e811b8e64e174d6b84ff672feb3172d2DefaultConsequenceInvokerGenerated.evaluate(Unknown Source) at my.company.user.rules.Rule_SomeRule_39_e811b8e64e174d6b84ff672feb3172d2DefaultConsequenceInvoker.evaluate(Unknown Source) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287) ... 37 more I have checked my DRL sources and verified that I am not doing any null checks, and I am certainly not doing any "null" checks either. Does anyone out there happen to know why this error is occuring? The source for that rule is: rule "SomeRule_39" when subScore1 : SubScore1() subScore2 : SubScore2() subScore3 : SubScore3() subScore4 : SubScore4() subScore5 : SubScore5() subScore6 : SubScore6() subScore7 : SubScore7() subScore8 : SubScore8() subScore9 : SubScore9() subScore10 : SubScore10() then TotalScore totalScore = new TotalScore(subScore1.getValue() + subScore2.getValue() + subScore3.getValue() + subScore4.getValue() + subScore5.getValue() + subScore6.getValue() + subScore7.getValue() + subScore8.getValue() + subScore9.getValue() + subScore10.getValue()); insert(totalScore); end Thanks for any insight! -DT -- View this message in context: http://drools.46999.n3.nabble.com/Drools-5-2-5-5-problems-tp4022168.html Sent from the Drools: User forum mailing list archive at Nabble.com.