public void notifyReAuthentication() {
    if (_messageDispatcher == null) {
      return;
    }

    // use another thread to do the notification so that the server operation won't be blocked
    ExecutorService threadPool =
        _cache.getDistributionManager().getExecutors().getWaitingThreadPool();
    threadPool.submit(() -> _messageDispatcher.notifyReAuthentication());
  }
Returns whether the proxy is alive. It is alive if its message dispatcher is processing
messages.

@return whether the proxy is alive
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientProxy.java