change default value of heartbeat interval and timeout when tcpmux enabled (#4186)

Release.md

@@ -1,3 +1,9 @@
+### Notable Changes
+
+We have optimized the heartbeat mechanism when tcpmux is enabled (enabled by default). The default value of `heartbeatInterval` has been adjusted to -1. This update ensures that when tcpmux is active, the client does not send additional heartbeats to the server. Since tcpmux incorporates its own heartbeat system, this change effectively reduces unnecessary data consumption, streamlining communication efficiency between client and server.
+
+When connecting to frps versions older than v0.39.0 might encounter compatibility issues due to changes in the heartbeat mechanism. As a temporary workaround, setting the `heartbeatInterval` to 30 can help maintain stable connectivity with these older versions. We recommend updating to the latest frps version to leverage full functionality and improvements.
+
 ### Features
 
 * Show tcpmux proxies on the frps dashboard.

client/control.go

@@ -20,8 +20,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/samber/lo"
-
 	"github.com/fatedier/frp/client/proxy"
 	"github.com/fatedier/frp/client/visitor"
 	"github.com/fatedier/frp/pkg/auth"
@@ -236,10 +234,8 @@ func (ctl *Control) registerMsgHandlers() {
 func (ctl *Control) heartbeatWorker() {
 	xl := ctl.xl
 
-	// TODO(fatedier): Change default value of HeartbeatInterval to -1 if tcpmux is enabled.
-	// Users can still enable heartbeat feature by setting HeartbeatInterval to a positive value.
 	if ctl.sessionCtx.Common.Transport.HeartbeatInterval > 0 {
-		// send heartbeat to server
+		// Send heartbeat to server.
 		sendHeartBeat := func() (bool, error) {
 			xl.Debugf("send heartbeat to server")
 			pingMsg := &msg.Ping{}
@@ -263,10 +259,8 @@ func (ctl *Control) heartbeatWorker() {
 		)
 	}
 
-	// Check heartbeat timeout only if TCPMux is not enabled and users don't disable heartbeat feature.
-	if ctl.sessionCtx.Common.Transport.HeartbeatInterval > 0 && ctl.sessionCtx.Common.Transport.HeartbeatTimeout > 0 &&
-		!lo.FromPtr(ctl.sessionCtx.Common.Transport.TCPMux) {
-
+	// Check heartbeat timeout.
+	if ctl.sessionCtx.Common.Transport.HeartbeatInterval > 0 && ctl.sessionCtx.Common.Transport.HeartbeatTimeout > 0 {
 		go wait.Until(func() {
 			if time.Since(ctl.lastPong.Load().(time.Time)) > time.Duration(ctl.sessionCtx.Common.Transport.HeartbeatTimeout)*time.Second {
 				xl.Warnf("heartbeat timeout")

pkg/config/v1/client.go

@@ -136,8 +136,14 @@ func (c *ClientTransportConfig) Complete() {
 	c.PoolCount = util.EmptyOr(c.PoolCount, 1)
 	c.TCPMux = util.EmptyOr(c.TCPMux, lo.ToPtr(true))
 	c.TCPMuxKeepaliveInterval = util.EmptyOr(c.TCPMuxKeepaliveInterval, 60)
-	c.HeartbeatInterval = util.EmptyOr(c.HeartbeatInterval, 30)
-	c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, 90)
+	if lo.FromPtr(c.TCPMux) {
+		// If TCPMux is enabled, heartbeat of application layer is unnecessary because we can rely on heartbeat in tcpmux.
+		c.HeartbeatInterval = util.EmptyOr(c.HeartbeatInterval, -1)
+		c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, -1)
+	} else {
+		c.HeartbeatInterval = util.EmptyOr(c.HeartbeatInterval, 30)
+		c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, 90)
+	}
 	c.QUIC.Complete()
 	c.TLS.Complete()
 }

pkg/config/v1/server.go

@@ -179,7 +179,12 @@ func (c *ServerTransportConfig) Complete() {
 	c.TCPMuxKeepaliveInterval = util.EmptyOr(c.TCPMuxKeepaliveInterval, 60)
 	c.TCPKeepAlive = util.EmptyOr(c.TCPKeepAlive, 7200)
 	c.MaxPoolCount = util.EmptyOr(c.MaxPoolCount, 5)
-	c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, 90)
+	if lo.FromPtr(c.TCPMux) {
+		// If TCPMux is enabled, heartbeat of application layer is unnecessary because we can rely on heartbeat in tcpmux.
+		c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, -1)
+	} else {
+		c.HeartbeatTimeout = util.EmptyOr(c.HeartbeatTimeout, 90)
+	}
 	c.QUIC.Complete()
 	if c.TLS.TrustedCaFile != "" {
 		c.TLS.Force = true

server/control.go

@@ -297,20 +297,18 @@ func (ctl *Control) GetWorkConn() (workConn net.Conn, err error) {
 }
 
 func (ctl *Control) heartbeatWorker() {
-	xl := ctl.xl
-
-	// Don't need application heartbeat if TCPMux is enabled,
-	// yamux will do same thing.
-	// TODO(fatedier): let default HeartbeatTimeout to -1 if TCPMux is enabled. Users can still set it to positive value to enable it.
-	if !lo.FromPtr(ctl.serverCfg.Transport.TCPMux) && ctl.serverCfg.Transport.HeartbeatTimeout > 0 {
-		go wait.Until(func() {
-			if time.Since(ctl.lastPing.Load().(time.Time)) > time.Duration(ctl.serverCfg.Transport.HeartbeatTimeout)*time.Second {
-				xl.Warnf("heartbeat timeout")
-				ctl.conn.Close()
-				return
-			}
-		}, time.Second, ctl.doneCh)
+	if ctl.serverCfg.Transport.HeartbeatTimeout <= 0 {
+		return
 	}
+
+	xl := ctl.xl
+	go wait.Until(func() {
+		if time.Since(ctl.lastPing.Load().(time.Time)) > time.Duration(ctl.serverCfg.Transport.HeartbeatTimeout)*time.Second {
+			xl.Warnf("heartbeat timeout")
+			ctl.conn.Close()
+			return
+		}
+	}, time.Second, ctl.doneCh)
 }
 
 // block until Control closed