Disable http2 until we have upstream bugs fixed (#7711)

We should revert this PR in future once we
have upstream bugs fixed regarding http2 behavior

cmd/http/server.go

@@ -26,7 +26,6 @@ import (
 	"time"
 
 	humanize "github.com/dustin/go-humanize"
-	"golang.org/x/net/http2"
 
 	"github.com/minio/minio-go/v6/pkg/set"
 	"github.com/minio/minio/pkg/certs"
@@ -56,9 +55,6 @@ const (
 
 	// DefaultMaxHeaderBytes - default maximum HTTP header size in bytes.
 	DefaultMaxHeaderBytes = 1 * humanize.MiByte
-
-	// DefaultHTTP2MaxConcurrentStreams - default value for HTTP 2.0 maximum concurrent streams allowed.
-	DefaultHTTP2MaxConcurrentStreams = 1024
 )
 
 // Server - extended http.Server supports multiple addresses to serve and enhanced connection handling.
@@ -133,11 +129,6 @@ func (srv *Server) Start() (err error) {
 
 	// Start servicing with listener.
 	if tlsConfig != nil {
-		if err = http2.ConfigureServer(&srv.Server, &http2.Server{
-			MaxConcurrentStreams: DefaultHTTP2MaxConcurrentStreams,
-		}); err != nil {
-			return err
-		}
 		return srv.Server.Serve(tls.NewListener(listener, tlsConfig))
 	}
 	return srv.Server.Serve(listener)
@@ -211,7 +202,14 @@ func NewServer(addrs []string, handler http.Handler, getCert certs.GetCertificat
 			CipherSuites:             defaultCipherSuites,
 			CurvePreferences:         secureCurves,
 			MinVersion:               tls.VersionTLS12,
-			NextProtos:               []string{"h2", "http/1.1"},
+			// Do not edit the next line, protos priority is kept
+			// on purpose in this manner for HTTP 2.0, we would
+			// still like HTTP 2.0 clients to negotiate connection
+			// to server if needed but by default HTTP 1.1 is
+			// expected. We need to change this in future
+			// when we wish to go back to HTTP 2.0 as default
+			// priority for HTTP protocol negotiation.
+			NextProtos: []string{"http/1.1", "h2"},
 		}
 		tlsConfig.GetCertificate = getCert
 	}

cmd/rest/client.go

@@ -28,7 +28,6 @@ import (
 	"time"
 
 	xhttp "github.com/minio/minio/cmd/http"
-	"golang.org/x/net/http2"
 )
 
 // DefaultRESTTimeout - default RPC timeout is one minute.
@@ -118,12 +117,6 @@ func NewClient(url *url.URL, tlsConfig *tls.Config, timeout time.Duration, newAu
 		TLSClientConfig:       tlsConfig,
 		DisableCompression:    true,
 	}
-	if tlsConfig != nil {
-		// If TLS is enabled configure http2
-		if err := http2.ConfigureTransport(tr); err != nil {
-			return nil, err
-		}
-	}
 	return &Client{
 		httpClient:          &http.Client{Transport: tr},
 		httpIdleConnsCloser: tr.CloseIdleConnections,