@VisibleForTesting
  JobCoordinatorMetadataManager createJobCoordinatorMetadataManager() {
    return new JobCoordinatorMetadataManager(new NamespaceAwareCoordinatorStreamStore(metadataStore,
        SetJobCoordinatorMetadataMessage.TYPE), JobCoordinatorMetadataManager.ClusterType.YARN, metrics);
  }
Stops all components of the JobCoordinator.
samza-core/src/main/java/org/apache/samza/clustermanager/ClusterBasedJobCoordinator.java