I am using global slf4j log4j logger as a global variable within our drl and inserting that global logger value at runtime into kiesession. While we are trying to do logger.info with multiple arguments then it's giving the following exception stack trace - Exception executing consequence for rule "Test Logger 2" in test.rules.system: java.lang.RuntimeException: cannot invoke method: info at org.drools.core.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39) at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1027) at org.drools.core.phreak.RuleExecutor.fire(RuleExecutor.java:129) at org.drools.core.phreak.RuleExecutor.evaluateNetworkAndFire(RuleExecutor.java:71) at org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:935) at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1200) at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:952) at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:926) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:232) at test.platform.rules.executor.service.impl.RuleExecutorServiceImplTest.testExecuteRule(RuleExecutorServiceImplTest.java:230) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83) at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: java.lang.RuntimeException: cannot invoke method: info at org.mvel2.optimizers.impl.refl.nodes.MethodAccessor.getValue(MethodAccessor.java:63) at org.mvel2.optimizers.impl.refl.nodes.VariableAccessor.getValue(VariableAccessor.java:37) at org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:108) at org.mvel2.MVELRuntime.execute(MVELRuntime.java:86) at org.mvel2.compiler.CompiledExpression.getDirectValue(CompiledExpression.java:123) at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:119) at org.mvel2.MVEL.executeExpression(MVEL.java:930) at org.drools.core.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:107) at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1016) ... 36 more Caused by: java.lang.ArrayIndexOutOfBoundsException: 1 at org.mvel2.optimizers.impl.refl.nodes.MethodAccessor.executeAll(MethodAccessor.java:140) at org.mvel2.optimizers.impl.refl.nodes.MethodAccessor.getValue(MethodAccessor.java:48) ... 44 more Example: My drl file looks like this - package test.system.rule; import test.platform.model.*; import org.slf4j.Logger; global Logger logger; rule "Test Logger 1" when then logger.info("within test logger 1"); end rule "Test Logger 2" when then logger.info("within test logger 2. Rule fired {}", drools.getRule().getName()); end While rules are firing then the first logger is getting printed into console but second one is not getting printed and giving the above exception to me. -- View this message in context: http://drools.46999.n3.nabble.com/Slf4j-Log4j-logger-not-working-with-Dro... Sent from the Drools: User forum mailing list archive at Nabble.com.