Description of problem:

Drools 6.0.0.CR5 appears to have introduced an intermittent issue where events being processed against the SLAViolation rule do not locate the 'ServiceResponseTimes' entry point.

With drools debug enabled, it shows:

15:47:59,902 INFO  [org.drools.compiler.kie.builder.impl.KieRepositoryImpl] (ServerService Thread Pool -- 66) KieModule was added:MemoryKieModule[ ReleaseId=org.default:artifact:1.0.0-SNAPSHOT]
15:47:59,901 INFO  [org.drools.compiler.kie.builder.impl.KieRepositoryImpl] (ServerService Thread Pool -- 72) KieModule was added:MemoryKieModule[ ReleaseId=org.default:artifact:1.0.0-SNAPSHOT]
15:48:00,040 DEBUG [org.drools.core.reteoo.ReteooRuleBase] (ServerService Thread Pool -- 66) Starting Engine in PHREAK mode
15:48:00,042 DEBUG [org.drools.core.reteoo.ReteooRuleBase] (ServerService Thread Pool -- 72) Starting Engine in PHREAK mode
15:48:00,115 TRACE [org.drools.core.phreak.AddRemoveRule] (ServerService Thread Pool -- 66) Adding Rule Create situation to represent exception
15:48:00,149 TRACE [org.drools.core.phreak.AddRemoveRule] (ServerService Thread Pool -- 72) Adding Rule Create situation to represent exception
15:48:00,175 TRACE [org.drools.core.reteoo.SegmentMemory] (ServerService Thread Pool -- 72) LinkNode notify=true nmask=1 smask=1 spos=0 rules=[RuleMem Create situation to represent exception]
15:48:00,176 TRACE [org.drools.core.reteoo.SegmentMemory] (ServerService Thread Pool -- 66) LinkNode notify=true nmask=1 smask=1 spos=0 rules=[RuleMem Create situation to represent exception]
15:48:00,192 FINEST [org.overlord.rtgov.ep.drools.DroolsEventProcessor] (ServerService Thread Pool -- 72) DroolsEventProcessor init: ruleName=SLAViolation session=org.drools.core.impl.StatefulKnowledgeSessionImpl@7b1868c3
15:48:00,192 FINEST [org.overlord.rtgov.ep.drools.DroolsEventProcessor] (ServerService Thread Pool -- 66) DroolsEventProcessor init: ruleName=RaiseSituationForException session=org.drools.core.impl.StatefulKnowledgeSessionImpl@7f861957

Two different rules are being initialized in separate threads, 'SLAViolation' and 'RaiseSituationForException'. However in the TRACE lines, it shows that one rules has been initialized in both threads.

Solution is to synchronize the creation of the session.