protected int getWorkersAlive() {
    int count = 0;
    for (int i = 0; i < asyncRequestWorkers.size(); i++) {
      if (asyncRequestWorkers.get(i).isRunning()) {
        count++;
      }
    }
    return count;
  }
Returns how many {@link AsyncRequestWorker}s are alive and well.
@return number of {@link AsyncRequestWorker}s alive and well.
ambry-rest/src/main/java/com/github/ambry/rest/AsyncRequestResponseHandler.java