code: public synchronized void disconnect() {
      if (mConnected) {
        Preconditions.checkNotNull(mChannel, PreconditionMessage.CHANNEL_NULL_WHEN_CONNECTED);
        LOG.debug("Disconnecting from the {} @ {}", getServiceName(), mAddress);
        beforeDisconnect();
        mChannel.shutdown();
        mConnected = false;
        afterDisconnect();
      }
    }
docs: Closes the connection with the Alluxio remote and does the necessary cleanup. It should be used
  if the client has not connected with the remote for a while, for example.