@Override
  public void close() {
    if (persistorFuture != null) {
      // cancel the future.
      persistorFuture.cancel(false);
      // refresh the token one more time.
      persistToken();
    }
  }
Disable this {@link RemoteTokenTracker} and cancel the scheduled persistor.
ambry-store/src/main/java/com/github/ambry/store/RemoteTokenTracker.java