Finally, we SHOULD tell our (HBONE) peers we are shutting down.
This can help ensure that clients do not hold onto pooled connections for too long.
This is not strictly required; Ztunnel clients have both keepalives (which will start to fail once the other end is shut down) and pool idle timeouts (which will close the connection when it has had no activity for some period; because the backend is gone, there will be no activity).

                                tcpKeepalive:
                                  description: If set then set SO_KEEPALIVE on the
                                    socket to enable TCP Keepalives.
                                  properties:
                                    interval:
                                      description: The time duration between keep-alive

  @Throws(SocketException::class)
  override fun getTcpNoDelay(): Boolean {
    return delegate!!.tcpNoDelay
  }

  @Throws(SocketException::class)
  override fun setKeepAlive(keepAlive: Boolean) {
    delegate!!.keepAlive = keepAlive
  }

  @Throws(SocketException::class)
  override fun setSendBufferSize(size: Int) {
    delegate!!.sendBufferSize = size
  }

  @Throws(SocketException::class)

				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
			}

			// Set tcp user timeout in addition to the keep-alive - tcp-keepalive is not enough to close a socket
			// with dead end because tcp-keepalive is not fired when there is data in the socket buffer.
			//    https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/

	if args.MaxReconnectInterval == 0 {
		// Default interval
		// https://github.com/eclipse/paho.mqtt.golang/blob/master/options.go#L115
		args.MaxReconnectInterval = 10 * time.Minute
	}

	if args.KeepAlive == 0 {
		args.KeepAlive = 10 * time.Second
	}

	var queueStore store.Store[event.Event]
	if args.QueueDir != "" {
		queueDir := filepath.Join(args.QueueDir, storePrefix+"-mqtt-"+id)

    canceled = true
    stream?.closeLater(ErrorCode.CANCEL)
  }

  companion object {
    private const val CONNECTION = "connection"
    private const val HOST = "host"
    private const val KEEP_ALIVE = "keep-alive"
    private const val PROXY_CONNECTION = "proxy-connection"
    private const val TRANSFER_ENCODING = "transfer-encoding"
    private const val TE = "te"
    private const val ENCODING = "encoding"

      env:
        # Set the DEVELOCITY_ACCESS_KEY so that Gradle Build Scans are generated
        DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
        # Potential stop-gap solution for ReadTimeout issues with the Gradle Build Cache
        # https://gradle.slack.com/archives/CHDLT99C6/p1636477584059200
        GRADLE_OPTS: -Dhttp.keepAlive=false

            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            proxy_connect_timeout 300;
            # Default is HTTP/1, keepalive is only enabled in HTTP/1.1
            proxy_http_version 1.1;
            proxy_set_header Connection "";
            chunked_transfer_encoding off;

            proxy_pass http://minio;
        }
    }

            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            proxy_connect_timeout 300;
            # Default is HTTP/1, keepalive is only enabled in HTTP/1.1
            proxy_http_version 1.1;
            proxy_set_header Connection "";
            chunked_transfer_encoding off;

            proxy_pass http://minio;
        }
    }

		// Remove failed listings after 5 minutes.
		return time.Since(cache.lastUpdate) > 5*time.Minute
	}
	return true
}

// keepAlive will continuously update lastHandout until ctx is canceled.
func (m metacache) keepAlive(ctx context.Context, rpc *peerRESTClient) {
	// we intentionally operate on a copy of m, so we can update without locks.
	t := time.NewTicker(metacacheMaxClientWait / 10)