if err != nil {
		return nil, err
	}
	dialer := &net.Dialer{
		Timeout: 5 * time.Second,
	}
	var res TestGrid
	res.Hosts = hosts
	ready := make(chan struct{})
	ctx, cancel := context.WithCancel(context.Background())
	res.cancel = cancel
	for i, host := range hosts {
		manager, err := NewManager(ctx, ManagerOptions{
			Dialer: dialer.DialContext,
			Local:  host,
			Hosts:  hosts,

		toDial = strings.Replace(toDial, "https://", "wss://", 1)
		toDial += RoutePath

		dialer := ws.DefaultDialer
		dialer.ReadBufferSize = readBufferSize
		dialer.WriteBufferSize = writeBufferSize
		dialer.Timeout = defaultDialTimeout
		if c.dialer != nil {
			dialer.NetDial = c.dialer.DialContext
		}
		if c.header == nil {
			c.header = make(http.Header, 2)
		}

	if lookupHost == nil {
		lookupHost = net.DefaultResolver.LookupHost
	}

	if baseDialCtx == nil {
		// This is same as which `http.DefaultTransport` uses.
		baseDialCtx = (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
		}).DialContext
	}

	return func(ctx context.Context, network, addr string) (conn net.Conn, err error) {
		host, port, err := net.SplitHostPort(addr)

// deliver a final empty token (which is different from a nil token).
// One could achieve the same behavior with a custom error value but
// providing one here is tidier.
// See the emptyFinalToken example for a use of this value.
var ErrFinalToken = errors.New("final token")

// Scan advances the [Scanner] to the next token, which will then be

func getHostFromSrv(records []dns.SrvRecord) (host string) {
	hosts := getHostsSlice(records)
	rng := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
	var d net.Dialer
	var retry int
	for retry < len(hosts) {
		ctx, cancel := context.WithTimeout(GlobalContext, 300*time.Millisecond)

		host = hosts[rng.Intn(len(hosts))]
		conn, err := d.DialContext(ctx, "tcp", host)
		cancel()

	local string

	// Validate incoming requests.
	authRequest func(r *http.Request) error
}

// ManagerOptions are options for creating a new grid manager.
type ManagerOptions struct {
	Dialer       ContextDialer               // Outgoing dialer.
	Local        string                      // Local host name.
	Hosts        []string                    // All hosts, including local in the grid.

				// concurrently, check for it before we
				// write the filler byte.
				select {
				case err := <-doneCh:
					if err != nil {
						write([]byte{1})
						write([]byte(err.Error()))
					} else {
						write([]byte{0})
					}
					return
				default:
				}

				// Response not ready, write a filler byte.
				write([]byte{32})
				if canWrite {
					w.(http.Flusher).Flush()

var globalGridStart = make(chan struct{})

func initGlobalGrid(ctx context.Context, eps EndpointServerPools) error {
	hosts, local := eps.GridHosts()
	g, err := grid.NewManager(ctx, grid.ManagerOptions{
		Dialer:       grid.ContextDialer(xhttp.DialContextWithLookupHost(globalDNSCache.LookupHost, xhttp.NewInternodeDialContext(rest.DefaultTimeout, globalTCPOptions))),
		Local:        local,
		Hosts:        hosts,

		Endpoint: endpoint,
	}
	for _, setter := range setters {
		setter(args)
	}
	args.httpClient = &http.Client{
		Transport: &http.Transport{
			Proxy: http.ProxyFromEnvironment,
			DialContext: (&net.Dialer{
				Timeout:   3 * time.Second,
				KeepAlive: 5 * time.Second,
			}).DialContext,
			ResponseHeaderTimeout: 3 * time.Second,
			TLSHandshakeTimeout:   3 * time.Second,
			ExpectContinueTimeout: 3 * time.Second,

)

const (
	shutdownPollIntervalMax = 500 * time.Millisecond

	// DefaultShutdownTimeout - default shutdown timeout to gracefully shutdown server.
	DefaultShutdownTimeout = 5 * time.Second

	// DefaultIdleTimeout for idle inactive connections
	DefaultIdleTimeout = 30 * time.Second

	// DefaultReadHeaderTimeout for very slow inactive connections
	DefaultReadHeaderTimeout = 30 * time.Second