Hi, folks,

I’m using Drools 5.1, MVEL dialect, JDK 1.6 to build a OLTP system running on tomcat 6.0.28. the runtime environment is on a cloud virtual and node profile is relatively small. We’ve noticed below run time exceptions from prod since it’s online from day one which is impacting transaction processing. However it is happening adhoc-ly. Here I have 1 question:

1. The yellow marked lines are actually java file compiled from DRL file. Why there is null pointer exception thrown from org.drools.common.DefaultAgenda.fireActivation?

ERROR>2012-02-25 11:42:25,071 com.xxx.xxx.xxx.xxx[DefaultQuartzScheduler_Worker-3]: Rules run time error:

org.drools.runtime.rule.ConsequenceException: rule: Match

        at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)

        at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:916)

        at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:845)

        at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1056)

        at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:733)

        at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:699)

        at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)

        at com. xxx.xxx.xxx.xxx.xxx.xxx.xxx (SessionManager.java:94)

        at com. xxx.xxx.xxx.xxx.xxx.xxx.yyy(SessionManagerJob.java:17)

        at org.quartz.core.JobRunShell.run(JobRunShell.java:202)

        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)

Caused by: java.lang.NullPointerException

        at com.xxx.xxx.xxx.xxx.xxx.xxx.xxx(xxx.java:634)

        at com.xxx.xxx.xxx.xxx.xxx.yyy.yyy(yyy.java:227)

        at com.xxx.xxx.xxx.xxx.xxx.yyy.zzz(zzz.java:115)

        at com.xxx.xxx.xxx.xxx.xxx.yyy.ttt(ttt.java:83)

        at com.xxx.xxx.xxx.xxx.xxx.yyy.uuu(uuu.java:75)

at com. com.xxx.xxx.xxx.xxx.xxx.yyy.vvv(vvv.java:9)

        at com. com.xxx.xxx.xxx.xxx.xxx.yyy.www(www.java:28)

        at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:906)

        ... 9 more

Best regards

Abe