private static boolean hasCache(DistributionManager manager) {
    InternalCache cache = manager.getCache();
    return cache != null && !cache.isClosed();
  }
Sends a shutdownAll request to all other members and performs local shutdownAll processing in
the waitingThreadPool.
geode-core/src/main/java/org/apache/geode/internal/admin/remote/ShutdownAllRequest.java