UN-5213: Increase MaxStreams value for QUIC transport

The default max streams value of 100 is rather small when subject to
high load in terms of connecting QUIC with streams faster than it can
create new ones. This high value allows for more throughput.

connection/connection.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"math"
 	"net/http"
 	"strconv"
 	"strings"
@@ -19,6 +20,7 @@ const (
 	lbProbeUserAgentPrefix = "Mozilla/5.0 (compatible; Cloudflare-Traffic-Manager/1.0; +https://www.cloudflare.com/traffic-manager/;"
 	LogFieldConnIndex      = "connIndex"
 	MaxGracePeriod         = time.Minute * 3
+	MaxConcurrentStreams   = math.MaxUint32
 )
 
 var switchingProtocolText = fmt.Sprintf("%d %s", http.StatusSwitchingProtocols, http.StatusText(http.StatusSwitchingProtocols))

connection/http2.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"math"
 	"net"
 	"net/http"
 	"runtime/debug"
@@ -60,7 +59,7 @@ func NewHTTP2Connection(
 	return &HTTP2Connection{
 		conn: conn,
 		server: &http2.Server{
-			MaxConcurrentStreams: math.MaxUint32,
+			MaxConcurrentStreams: MaxConcurrentStreams,
 		},
 		config:               config,
 		connOptions:          connOptions,

origin/tunnel.go

@@ -358,7 +358,6 @@ func serveTunnel(
 			config,
 			connOptions,
 			controlStream,
-			connectedFuse,
 			reconnectCh,
 			gracefulShutdownC)
 
@@ -509,15 +508,16 @@ func ServeQUIC(
 	config *TunnelConfig,
 	connOptions *tunnelpogs.ConnectionOptions,
 	controlStreamHandler connection.ControlStreamHandler,
-	connectedFuse connection.ConnectedFuse,
 	reconnectCh chan ReconnectSignal,
 	gracefulShutdownC <-chan struct{},
 ) (err error, recoverable bool) {
 	tlsConfig := config.EdgeTLSConfigs[connection.QUIC]
 	quicConfig := &quic.Config{
-		HandshakeIdleTimeout: quicHandshakeIdleTimeout,
+		HandshakeIdleTimeout:  quicHandshakeIdleTimeout,
-		MaxIdleTimeout:       quicMaxIdleTimeout,
+		MaxIdleTimeout:        quicMaxIdleTimeout,
-		KeepAlive:            true,
+		MaxIncomingStreams:    connection.MaxConcurrentStreams,
+		MaxIncomingUniStreams: connection.MaxConcurrentStreams,
+		KeepAlive:             true,
 	}
 	for {
 		select {