[jboss-jira] [JBoss JIRA] (DROOLS-368) Memory leak mappedKnowledgeBaseListeners

Memory leak mappedKnowledgeBaseListeners ---------------------------------------- Key: DROOLS-368 URL: https://issues.jboss.org/browse/DROOLS-368 Project: Drools Issue Type: Bug Affects Versions: 5.5.0.Final Environment: Linex Reporter: David Tse Assignee: Petr Široký Priority: Critical This leak is identified by getting a heap dump. Analysis of the heap dump by Eclipse MAT puts org.drools.retoo.ReteooRuleBase as the prime suspect holding to 47.33% of the 870 MB heap memory with org.drools.retoo.ReteooStatefulSession adding to the problem accounting for an additional 5.25% of the memory leak. Examination of the BRMS 5.5.0.Final source code indicates that SFT memory leaks are caused by issues associated with 7 classes in the drools-core module of the community version BRMS 5.5.0.Final. These classes are • org.drools.impl.KnowledgeBaseImpl.java • org.drools.impl.StatefulKnowledgeSession.java • org.drools.retoo.ReteooStatefulSession which extends org.drools.retoo.ReteooWorkingMemory.java which extends org.drools.common.AbstractWorkingMemory.java • org.drools.retoo.ReteooRuleBase.java which extends org.drools.common.AbstractRuleBase.java The code in the community version has cyclic dependency and these developed into dying pointers. 1. org.drools.impl.KnowledgeBaseImpl$KnowledgeBaseEventListenerWrapper is holding a reference to this (KnowledgeBaseImpl) 2. KnowledgeBaseImpl is holding a reference to RuleBase (ReteooRuleBase is the implementation class) 3. ReteooRuleBase is holding a reference to org.drools.impl.KnowledgeBaseImpl$KnowledgeBaseEventListenerWrapper For the second leak, StatefulKnowledgeSessionImpl is holding a reference to ReteooWorkingMemory. ReteooWorkingMemory is also holding a reference to StatefulKnowledgeSessionImpl.