private static void startWatchDog() {
    if (failureActionCompleted) {
      return;
    }
    synchronized (failureSync) {
      if (watchDog != null && watchDog.isAlive()) {
        return;
      }
      watchDog = new LoggingThread("SystemFailure WatchDog", SystemFailure::runWatchDog);
      watchDog.start();
    }
  }
Start the watchdog thread, if it isn't already running.
geode-core/src/main/java/org/apache/geode/SystemFailure.java