Each call to KieContainer.updateToVersion(ReleaseId version) creates a new classloader for unmodifed rules in the KieModule ---------------------------------------------------------------------------------------------------------------------------- Key: DROOLS-1372 URL: https://issues.jboss.org/browse/DROOLS-1372 Project: Drools Issue Type: Bug Components: core engine Affects Versions: 6.3.0.Final Reporter: Bill Tuminaro Assignee: Mario Fusco Priority: Major Attachments: UpdateToVersionCreatingNewClassloaders.java, drools-1372_one.PNG, drools-1372_two.PNG I have attached a reproducer named UpdateToVersionCreatingNewClassloaders.java that creates a KieContainer with a KieModule that contains a single rule (rule name 1081) and then runs a loop that adds 1 rule and removes 1 rule and calls KieContainer.updateToVersion(). Along the way it creates .dmp files. If you examine the .dmp files name updrule#_3.dmp (i.e. updrule1_3.dmp , updrule3_3.dmp ) you will see that the number of classloaders for the rule named org.drools.compiler.integrationTests.Rule_10810DefaultConsequenceInvoker increases by 1 each iteration.