lib/httpserver: reduce typical duration for http server graceful shutdown

Previously the duration for graceful shutdown for http server could take more than a minute
because of imporperly set timeouts in setNetworkTimeout.
Now typical duration for graceful shutdown should be reduced to less than 5 seconds.

lib/httpserver/httpserver.go

@@ -71,7 +71,6 @@ func Serve(addr string, rh RequestHandler) {
 	if err != nil {
 		logger.Fatalf("cannot start http server at %s: %s", addr, err)
 	}
-	setNetworkTimeouts(lnTmp)
 	ln := net.Listener(lnTmp)
 
 	if *tlsEnable {
@@ -87,29 +86,18 @@ func Serve(addr string, rh RequestHandler) {
 	serveWithListener(addr, ln, rh)
 }
 
-func setNetworkTimeouts(ln *netutil.TCPListener) {
-	// Set network-level read and write timeouts to reasonable values
-	// in order to protect from DoS or broken networks.
-	// Application-level timeouts must be set by the authors of request handlers.
-	//
-	// The read timeout limits the life of idle connection
-	ln.ReadTimeout = time.Minute
-	ln.WriteTimeout = time.Minute
-}
-
 func serveWithListener(addr string, ln net.Listener, rh RequestHandler) {
 	s := &http.Server{
 		Handler: gzipHandler(rh),
 
-		// Disable http/2
+		// Disable http/2, since it doesn't give any advantages for VictoriaMetrics services.
 		TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler)),
 
-		// Do not set ReadTimeout and WriteTimeout here.
+		ReadHeaderTimeout: 5 * time.Second,
-		// Network-level timeouts are set in setNetworkTimeouts.
+		IdleTimeout:       time.Minute,
-		// Application-level timeouts must be set in the app.
 
-		// Do not set IdleTimeout, since it is equivalent to read timeout
+		// Do not set ReadTimeout and WriteTimeout here,
-		// set in setNetworkTimeouts.
+		// since these timeouts must be controlled by request handlers.
 
 		ErrorLog: logger.StdErrorLogger(),
 	}

lib/ingestserver/opentsdbhttp/server.go

@@ -43,9 +43,11 @@ func MustStart(addr string, insertHandler func(req *http.Request) error) *Server
 func MustServe(ln net.Listener, insertHandler func(req *http.Request) error) *Server {
 	h := newRequestHandler(insertHandler)
 	hs := &http.Server{
-		Handler:      h,
+		Handler:           h,
-		ReadTimeout:  30 * time.Second,
+		ReadHeaderTimeout: 5 * time.Second,
-		WriteTimeout: 10 * time.Second,
+		IdleTimeout:       time.Minute,
+		// Do not set ReadTimeout and WriteTimeout here,
+		// since these timeouts must be controlled by request handler.
 	}
 	s := &Server{
 		s:  hs,

lib/netutil/conn.go

@@ -5,7 +5,6 @@ import (
 	"io"
 	"net"
 	"sync/atomic"
-	"time"
 
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -48,29 +47,12 @@ type statConn struct {
 
 	closeCalls uint64
 
-	readTimeout  time.Duration
-	lastReadTime time.Time
-
-	writeTimeout  time.Duration
-	lastWriteTime time.Time
-
 	net.Conn
 
 	cm *connMetrics
 }
 
 func (sc *statConn) Read(p []byte) (int, error) {
-	if sc.readTimeout > 0 {
-		t := time.Now()
-		if t.Sub(sc.lastReadTime) > sc.readTimeout>>4 {
-			d := t.Add(sc.readTimeout)
-			if err := sc.Conn.SetReadDeadline(d); err != nil {
-				// This error may occur when the client closes the connection before setting the deadline
-				return 0, err
-			}
-		}
-	}
-
 	n, err := sc.Conn.Read(p)
 	sc.cm.readCalls.Inc()
 	sc.cm.readBytes.Add(n)
@@ -85,17 +67,6 @@ func (sc *statConn) Read(p []byte) (int, error) {
 }
 
 func (sc *statConn) Write(p []byte) (int, error) {
-	if sc.writeTimeout > 0 {
-		t := time.Now()
-		if t.Sub(sc.lastWriteTime) > sc.writeTimeout>>4 {
-			d := t.Add(sc.writeTimeout)
-			if err := sc.Conn.SetWriteDeadline(d); err != nil {
-				// This error may accour when the client closes the connection before setting the deadline
-				return 0, err
-			}
-		}
-	}
-
 	n, err := sc.Conn.Write(p)
 	sc.cm.writeCalls.Inc()
 	sc.cm.writtenBytes.Add(n)

lib/netutil/tcplistener.go

@@ -49,20 +49,6 @@ func getNetwork() string {
 //
 // It also gathers various stats for the accepted connections.
 type TCPListener struct {
-	// ReadTimeout is timeout for each Read call on accepted conns.
-	//
-	// By default it isn't set.
-	//
-	// Set ReadTimeout before calling Accept the first time.
-	ReadTimeout time.Duration
-
-	// WriteTimeout is timeout for each Write call on accepted conns.
-	//
-	// By default it isn't set.
-	//
-	// Set WriteTimeout before calling Accept the first time.
-	WriteTimeout time.Duration
-
 	net.Listener
 
 	accepts      *metrics.Counter
@@ -87,9 +73,6 @@ func (ln *TCPListener) Accept() (net.Conn, error) {
 		}
 		ln.conns.Inc()
 		sc := &statConn{
-			readTimeout:  ln.ReadTimeout,
-			writeTimeout: ln.WriteTimeout,
-
 			Conn: conn,
 			cm:   &ln.connMetrics,
 		}