@Override
  public void close() {
    if (!closed) {
      shutdown();
      logger.info("Marking DistributionManager {} as closed.",
          localAddress);
      MembershipLogger.logShutdown(localAddress);
      closed = true;
    }
  }
This thread processes member events as they occur.

@see ClusterDistributionManager.MemberCrashedEvent
@see ClusterDistributionManager.MemberJoinedEvent
@see ClusterDistributionManager.MemberDepartedEvent
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterDistributionManager.java