After upgrading drools dependencies from version 6.0.2-SNAPSHOT to 6.1.0-SNAPSHOT, the mbeans that used to be created for each KieSession no longer get created.

The problem seems to have been introduced when the StatefulKnowledgeSessionImpl constructor was modified in this commit made by mfusco@redhat.com: https://github.com/droolsjbpm/drools/commit/1f8dc32725276a68456c5c4315c6a7c0b3f222ad

The previous version of the constructor made a call to StatefulKnowledgeSession.setKnowledgeRuntime(InternalKnowledgeRuntime kruntime), which resulted in the ksession mbean being created and registered.

I tried adding the following line to the end of the constructor, and the ksession mbeans started to get created again:

setKnowledgeRuntime(this);