Ensure WriteTimeout > TimeoutBroadcastTxCommit (#3443)

* Make sure config.TimeoutBroadcastTxCommit < rpcserver.WriteTimeout()

* remove redundant comment

* libs/rpc/http_server: move Read/WriteTimeout into Config

* increase defaults for read/write timeouts

Based on this article
https://www.digitalocean.com/community/tutorials/how-to-optimize-nginx-configuration

* WriteTimeout should be larger than TimeoutBroadcastTxCommit

* set a deadline for subscribing to txs

* extract duration into const

* add two changelog entries

* Update CHANGELOG_PENDING.md

Co-Authored-By: melekes <anton.kalyaev@gmail.com>

* Update CHANGELOG_PENDING.md

Co-Authored-By: melekes <anton.kalyaev@gmail.com>

* 12 -> 10

* changelog

* changelog

CHANGELOG.md

@@ -11,8 +11,8 @@ This release is primarily about the new pubsub implementation, dubbed `pubsub 2.
 like configurable limits on the number of active RPC subscriptions at a time (`max_subscription_clients`).
 Pubsub 2.0 is an improved version of the older pubsub that is non-blocking and has a nicer API.
 Note the improved pubsub API also resulted in some improvements to the HTTPClient interface and the API for WebSocket subscriptions.
-This release also adds a configurable limit to the mempool size, `max_txs_bytes`, with
-default 1GB, and includes many smaller improvements and bug-fixes.
+This release also adds a configurable limit to the mempool size (`max_txs_bytes`, default 1GB)
+and a configurable timeout for the `/broadcast_tx_commit` endpoint.
 
 See the [v0.31.0
 Milestone](https://github.com/tendermint/tendermint/milestone/19?closed=1) for
@@ -30,6 +30,7 @@ program](https://hackerone.com/tendermint).
     the subscription.
   - [rpc] [\#3269](https://github.com/tendermint/tendermint/issues/2826) Limit number of unique clientIDs with open subscriptions. Configurable via `rpc.max_subscription_clients`
   - [rpc] [\#3269](https://github.com/tendermint/tendermint/issues/2826) Limit number of unique queries a given client can subscribe to at once. Configurable via `rpc.max_subscriptions_per_client`.
+  - [rpc] [\#3435](https://github.com/tendermint/tendermint/issues/3435) Default ReadTimeout and WriteTimeout changed to 10s. WriteTimeout can increased by setting `rpc.timeout_broadcast_tx_commit` in the config.
   - [rpc/client] [\#3269](https://github.com/tendermint/tendermint/issues/3269) Update `EventsClient` interface to reflect new pubsub/eventBus API [ADR-33](https://github.com/tendermint/tendermint/blob/develop/docs/architecture/adr-033-pubsub.md). This includes `Subscribe`, `Unsubscribe`, and `UnsubscribeAll` methods.
 
 * Apps
@@ -43,6 +44,7 @@ program](https://hackerone.com/tendermint).
     * TrapSignal should not be responsible for blocking thread of execution
   - [libs/db] [\#3397](https://github.com/tendermint/tendermint/pull/3397) Add possibility to `Close()` `Batch` to prevent memory leak when using ClevelDB. (@Stumble)
   - [types] [\#3354](https://github.com/tendermint/tendermint/issues/3354) Remove RoundState from EventDataRoundState
+  - [rpc] [\#3435](https://github.com/tendermint/tendermint/issues/3435) `StartHTTPServer` / `StartHTTPAndTLSServer` now require a Config (use `rpcserver.DefaultConfig`)
 
 * Blockchain Protocol
 

config/config.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
-	rpcserver "github.com/tendermint/tendermint/rpc/lib/server"
 )
 
 const (
@@ -336,6 +335,9 @@ type RPCConfig struct {
 	MaxSubscriptionsPerClient int `mapstructure:"max_subscriptions_per_client"`
 
 	// How long to wait for a tx to be committed during /broadcast_tx_commit
+	// WARNING: Using a value larger than 10s will result in increasing the
+	// global HTTP write timeout, which applies to all connections and endpoints.
+	// See https://github.com/tendermint/tendermint/issues/3435
 	TimeoutBroadcastTxCommit time.Duration `mapstructure:"timeout_broadcast_tx_commit"`
 }
 
@@ -385,9 +387,6 @@ func (cfg *RPCConfig) ValidateBasic() error {
 	if cfg.TimeoutBroadcastTxCommit < 0 {
 		return errors.New("timeout_broadcast_tx_commit can't be negative")
 	}
-	if cfg.TimeoutBroadcastTxCommit > rpcserver.WriteTimeout {
-		return fmt.Errorf("timeout_broadcast_tx_commit can't be greater than rpc server's write timeout: %v", rpcserver.WriteTimeout)
-	}
 	return nil
 }
 

config/toml.go

@@ -176,6 +176,9 @@ max_subscription_clients = {{ .RPC.MaxSubscriptionClients }}
 max_subscriptions_per_client = {{ .RPC.MaxSubscriptionsPerClient }}
 
 # How long to wait for a tx to be committed during /broadcast_tx_commit.
+# WARNING: Using a value larger than 10s will result in increasing the
+# global HTTP write timeout, which applies to all connections and endpoints.
+# See https://github.com/tendermint/tendermint/issues/3435
 timeout_broadcast_tx_commit = "{{ .RPC.TimeoutBroadcastTxCommit }}"
 
 ##### peer to peer configuration options #####

docs/tendermint-core/configuration.md

@@ -122,6 +122,9 @@ max_subscription_clients = 100
 max_subscriptions_per_client = 5
 
 # How long to wait for a tx to be committed during /broadcast_tx_commit.
+# WARNING: Using a value larger than 10s will result in increasing the
+# global HTTP write timeout, which applies to all connections and endpoints.
+# See https://github.com/tendermint/tendermint/issues/3435
 timeout_broadcast_tx_commit = "10s"
 
 ##### peer to peer configuration options #####

lite/proxy/proxy.go

@@ -45,11 +45,13 @@ func StartProxy(c rpcclient.Client, listenAddr string, logger log.Logger, maxOpe
 	core.SetLogger(logger)
 	mux.HandleFunc(wsEndpoint, wm.WebsocketHandler)
 
-	l, err := rpcserver.Listen(listenAddr, rpcserver.Config{MaxOpenConnections: maxOpenConnections})
+	config := rpcserver.DefaultConfig()
+	config.MaxOpenConnections = maxOpenConnections
+	l, err := rpcserver.Listen(listenAddr, config)
 	if err != nil {
 		return err
 	}
-	return rpcserver.StartHTTPServer(l, mux, logger)
+	return rpcserver.StartHTTPServer(l, mux, logger, config)
 }
 
 // RPCRoutes just routes everything to the given client, as if it were

node/node.go

@@ -689,9 +689,18 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 		mux.HandleFunc("/websocket", wm.WebsocketHandler)
 		rpcserver.RegisterRPCFuncs(mux, rpccore.Routes, coreCodec, rpcLogger)
 
+		config := rpcserver.DefaultConfig()
+		config.MaxOpenConnections = n.config.RPC.MaxOpenConnections
+		// If necessary adjust global WriteTimeout to ensure it's greater than
+		// TimeoutBroadcastTxCommit.
+		// See https://github.com/tendermint/tendermint/issues/3435
+		if config.WriteTimeout <= n.config.RPC.TimeoutBroadcastTxCommit {
+			config.WriteTimeout = n.config.RPC.TimeoutBroadcastTxCommit + 1*time.Second
+		}
+
 		listener, err := rpcserver.Listen(
 			listenAddr,
-			rpcserver.Config{MaxOpenConnections: n.config.RPC.MaxOpenConnections},
+			config,
 		)
 		if err != nil {
 			return nil, err
@@ -711,6 +720,7 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 			listener,
 			rootHandler,
 			rpcLogger,
+			config,
 		)
 		listeners[i] = listener
 	}
@@ -718,8 +728,9 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 	// we expose a simplified api over grpc for convenience to app devs
 	grpcListenAddr := n.config.RPC.GRPCListenAddress
 	if grpcListenAddr != "" {
-		listener, err := rpcserver.Listen(
-			grpcListenAddr, rpcserver.Config{MaxOpenConnections: n.config.RPC.GRPCMaxOpenConnections})
+		config := rpcserver.DefaultConfig()
+		config.MaxOpenConnections = n.config.RPC.MaxOpenConnections
+		listener, err := rpcserver.Listen(grpcListenAddr, config)
 		if err != nil {
 			return nil, err
 		}

rpc/core/events.go

@@ -105,8 +105,7 @@ func Subscribe(ctx *rpctypes.Context, query string) (*ctypes.ResultSubscribe, er
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to parse query")
 	}
-
-	subCtx, cancel := context.WithTimeout(context.Background(), subscribeTimeout)
+	subCtx, cancel := context.WithTimeout(ctx.Context(), SubscribeTimeout)
 	defer cancel()
 	sub, err := eventBus.Subscribe(subCtx, addr, q)
 	if err != nil {

rpc/core/mempool.go

@@ -197,7 +197,7 @@ func BroadcastTxCommit(ctx *rpctypes.Context, tx types.Tx) (*ctypes.ResultBroadc
 	}
 
 	// Subscribe to tx being committed in block.
-	subCtx, cancel := context.WithTimeout(context.Background(), subscribeTimeout)
+	subCtx, cancel := context.WithTimeout(ctx.Context(), SubscribeTimeout)
 	defer cancel()
 	q := types.EventQueryTxFor(tx)
 	deliverTxSub, err := eventBus.Subscribe(subCtx, subscriber, q)

rpc/core/pipe.go

@@ -1,6 +1,8 @@
 package core
 
 import (
+	"time"
+
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/consensus"
 	"github.com/tendermint/tendermint/crypto"
@@ -9,7 +11,6 @@ import (
 	mempl "github.com/tendermint/tendermint/mempool"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/proxy"
-	rpcserver "github.com/tendermint/tendermint/rpc/lib/server"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/state/txindex"
 	"github.com/tendermint/tendermint/types"
@@ -19,9 +20,11 @@ const (
 	// see README
 	defaultPerPage = 30
 	maxPerPage     = 100
-)
 
-var subscribeTimeout = rpcserver.WriteTimeout / 2
+	// SubscribeTimeout is the maximum time we wait to subscribe for an event.
+	// must be less than the server's write timeout (see rpcserver.DefaultConfig)
+	SubscribeTimeout = 5 * time.Second
+)
 
 //----------------------------------------------
 // These interfaces are used by RPC and must be thread safe

rpc/lib/rpc_test.go

@@ -121,11 +121,12 @@ func setup() {
 	wm := server.NewWebsocketManager(Routes, RoutesCdc, server.ReadWait(5*time.Second), server.PingPeriod(1*time.Second))
 	wm.SetLogger(tcpLogger)
 	mux.HandleFunc(websocketEndpoint, wm.WebsocketHandler)
-	listener1, err := server.Listen(tcpAddr, server.Config{})
+	config := server.DefaultConfig()
+	listener1, err := server.Listen(tcpAddr, config)
 	if err != nil {
 		panic(err)
 	}
-	go server.StartHTTPServer(listener1, mux, tcpLogger)
+	go server.StartHTTPServer(listener1, mux, tcpLogger, config)
 
 	unixLogger := logger.With("socket", "unix")
 	mux2 := http.NewServeMux()
@@ -133,11 +134,11 @@ func setup() {
 	wm = server.NewWebsocketManager(Routes, RoutesCdc)
 	wm.SetLogger(unixLogger)
 	mux2.HandleFunc(websocketEndpoint, wm.WebsocketHandler)
-	listener2, err := server.Listen(unixAddr, server.Config{})
+	listener2, err := server.Listen(unixAddr, config)
 	if err != nil {
 		panic(err)
 	}
-	go server.StartHTTPServer(listener2, mux2, unixLogger)
+	go server.StartHTTPServer(listener2, mux2, unixLogger, config)
 
 	// wait for servers to start
 	time.Sleep(time.Second * 2)

rpc/lib/server/handlers.go

@@ -2,6 +2,7 @@ package rpcserver
 
 import (
 	"bytes"
+	"context"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -439,6 +440,9 @@ type wsConnection struct {
 
 	// callback which is called upon disconnect
 	onDisconnect func(remoteAddr string)
+
+	ctx    context.Context
+	cancel context.CancelFunc
 }
 
 // NewWSConnection wraps websocket.Conn.
@@ -532,6 +536,10 @@ func (wsc *wsConnection) OnStop() {
 	if wsc.onDisconnect != nil {
 		wsc.onDisconnect(wsc.remoteAddr)
 	}
+
+	if wsc.ctx != nil {
+		wsc.cancel()
+	}
 }
 
 // GetRemoteAddr returns the remote address of the underlying connection.
@@ -569,6 +577,16 @@ func (wsc *wsConnection) Codec() *amino.Codec {
 	return wsc.cdc
 }
 
+// Context returns the connection's context.
+// The context is canceled when the client's connection closes.
+func (wsc *wsConnection) Context() context.Context {
+	if wsc.ctx != nil {
+		return wsc.ctx
+	}
+	wsc.ctx, wsc.cancel = context.WithCancel(context.Background())
+	return wsc.ctx
+}
+
 // Read from the socket and subscribe to or unsubscribe from events
 func (wsc *wsConnection) readRoutine() {
 	defer func() {

rpc/lib/server/http_server.go

@@ -18,9 +18,23 @@ import (
 	types "github.com/tendermint/tendermint/rpc/lib/types"
 )
 
-// Config is an RPC server configuration.
+// Config is a RPC server configuration.
 type Config struct {
+	// see netutil.LimitListener
 	MaxOpenConnections int
+	// mirrors http.Server#ReadTimeout
+	ReadTimeout time.Duration
+	// mirrors http.Server#WriteTimeout
+	WriteTimeout time.Duration
+}
+
+// DefaultConfig returns a default configuration.
+func DefaultConfig() *Config {
+	return &Config{
+		MaxOpenConnections: 0, // unlimited
+		ReadTimeout:        10 * time.Second,
+		WriteTimeout:       10 * time.Second,
+	}
 }
 
 const (
@@ -30,25 +44,17 @@ const (
 
 	// same as the net/http default
 	maxHeaderBytes = 1 << 20
-
-	// Timeouts for reading/writing to the http connection.
-	// Public so handlers can read them -
-	// /broadcast_tx_commit has it's own timeout, which should
-	// be less than the WriteTimeout here.
-	// TODO: use a config instead.
-	ReadTimeout  = 3 * time.Second
-	WriteTimeout = 20 * time.Second
 )
 
 // StartHTTPServer takes a listener and starts an HTTP server with the given handler.
 // It wraps handler with RecoverAndLogHandler.
 // NOTE: This function blocks - you may want to call it in a go-routine.
-func StartHTTPServer(listener net.Listener, handler http.Handler, logger log.Logger) error {
+func StartHTTPServer(listener net.Listener, handler http.Handler, logger log.Logger, config *Config) error {
 	logger.Info(fmt.Sprintf("Starting RPC HTTP server on %s", listener.Addr()))
 	s := &http.Server{
 		Handler:        RecoverAndLogHandler(maxBytesHandler{h: handler, n: maxBodyBytes}, logger),
-		ReadTimeout:    ReadTimeout,
-		WriteTimeout:   WriteTimeout,
+		ReadTimeout:    config.ReadTimeout,
+		WriteTimeout:   config.WriteTimeout,
 		MaxHeaderBytes: maxHeaderBytes,
 	}
 	err := s.Serve(listener)
@@ -64,13 +70,14 @@ func StartHTTPAndTLSServer(
 	handler http.Handler,
 	certFile, keyFile string,
 	logger log.Logger,
+	config *Config,
 ) error {
 	logger.Info(fmt.Sprintf("Starting RPC HTTPS server on %s (cert: %q, key: %q)",
 		listener.Addr(), certFile, keyFile))
 	s := &http.Server{
 		Handler:        RecoverAndLogHandler(maxBytesHandler{h: handler, n: maxBodyBytes}, logger),
-		ReadTimeout:    ReadTimeout,
-		WriteTimeout:   WriteTimeout,
+		ReadTimeout:    config.ReadTimeout,
+		WriteTimeout:   config.WriteTimeout,
 		MaxHeaderBytes: maxHeaderBytes,
 	}
 	err := s.ServeTLS(listener, certFile, keyFile)
@@ -180,7 +187,7 @@ func (h maxBytesHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 // Listen starts a new net.Listener on the given address.
 // It returns an error if the address is invalid or the call to Listen() fails.
-func Listen(addr string, config Config) (listener net.Listener, err error) {
+func Listen(addr string, config *Config) (listener net.Listener, err error) {
 	parts := strings.SplitN(addr, "://", 2)
 	if len(parts) != 2 {
 		return nil, errors.Errorf(

rpc/lib/server/http_server_test.go

@@ -30,10 +30,12 @@ func TestMaxOpenConnections(t *testing.T) {
 		time.Sleep(10 * time.Millisecond)
 		fmt.Fprint(w, "some body")
 	})
-	l, err := Listen("tcp://127.0.0.1:0", Config{MaxOpenConnections: max})
+	config := DefaultConfig()
+	config.MaxOpenConnections = max
+	l, err := Listen("tcp://127.0.0.1:0", config)
 	require.NoError(t, err)
 	defer l.Close()
-	go StartHTTPServer(l, mux, log.TestingLogger())
+	go StartHTTPServer(l, mux, log.TestingLogger(), config)
 
 	// Make N GET calls to the server.
 	attempts := max * 2
@@ -64,15 +66,17 @@ func TestMaxOpenConnections(t *testing.T) {
 }
 
 func TestStartHTTPAndTLSServer(t *testing.T) {
+	config := DefaultConfig()
+	config.MaxOpenConnections = 1
 	// set up fixtures
 	listenerAddr := "tcp://0.0.0.0:0"
-	listener, err := Listen(listenerAddr, Config{MaxOpenConnections: 1})
+	listener, err := Listen(listenerAddr, config)
 	require.NoError(t, err)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {})
 
 	// test failure
-	err = StartHTTPAndTLSServer(listener, mux, "", "", log.TestingLogger())
+	err = StartHTTPAndTLSServer(listener, mux, "", "", log.TestingLogger(), config)
 	require.IsType(t, (*os.PathError)(nil), err)
 
 	// TODO: test that starting the server can actually work

rpc/lib/test/main.go

@@ -36,9 +36,10 @@ func main() {
 	cmn.TrapSignal(logger, func() {})
 
 	rpcserver.RegisterRPCFuncs(mux, routes, cdc, logger)
-	listener, err := rpcserver.Listen("0.0.0.0:8008", rpcserver.Config{})
+	config := rpcserver.DefaultConfig()
+	listener, err := rpcserver.Listen("0.0.0.0:8008", config)
 	if err != nil {
 		cmn.Exit(err.Error())
 	}
-	rpcserver.StartHTTPServer(listener, mux, logger)
+	rpcserver.StartHTTPServer(listener, mux, logger, config)
 }

rpc/lib/types/types.go

@@ -1,6 +1,7 @@
 package rpctypes
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -243,6 +244,8 @@ type WSRPCConnection interface {
 	TryWriteRPCResponse(resp RPCResponse) bool
 	// Codec returns an Amino codec used.
 	Codec() *amino.Codec
+	// Context returns the connection's context.
+	Context() context.Context
 }
 
 // Context is the first parameter for all functions. It carries a json-rpc
@@ -260,8 +263,12 @@ type Context struct {
 	HTTPReq *http.Request
 }
 
-// RemoteAddr returns either HTTPReq#RemoteAddr or result of the
-// WSConn#GetRemoteAddr().
+// RemoteAddr returns the remote address (usually a string "IP:port").
+// If neither HTTPReq nor WSConn is set, an empty string is returned.
+// HTTP:
+//		http.Request#RemoteAddr
+// WS:
+//		result of GetRemoteAddr
 func (ctx *Context) RemoteAddr() string {
 	if ctx.HTTPReq != nil {
 		return ctx.HTTPReq.RemoteAddr
@@ -271,6 +278,22 @@ func (ctx *Context) RemoteAddr() string {
 	return ""
 }
 
+// Context returns the request's context.
+// The returned context is always non-nil; it defaults to the background context.
+// HTTP:
+//		The context is canceled when the client's connection closes, the request
+//		is canceled (with HTTP/2), or when the ServeHTTP method returns.
+// WS:
+//		The context is canceled when the client's connections closes.
+func (ctx *Context) Context() context.Context {
+	if ctx.HTTPReq != nil {
+		return ctx.HTTPReq.Context()
+	} else if ctx.WSConn != nil {
+		return ctx.WSConn.Context()
+	}
+	return context.Background()
+}
+
 //----------------------------------------
 // SOCKETS
 

tools/tm-monitor/rpc.go

@@ -17,11 +17,12 @@ func startRPC(listenAddr string, m *monitor.Monitor, logger log.Logger) net.List
 	wm := rpc.NewWebsocketManager(routes, nil)
 	mux.HandleFunc("/websocket", wm.WebsocketHandler)
 	rpc.RegisterRPCFuncs(mux, routes, cdc, logger)
-	listener, err := rpc.Listen(listenAddr, rpc.Config{})
+	config := rpc.DefaultConfig()
+	listener, err := rpc.Listen(listenAddr, config)
 	if err != nil {
 		panic(err)
 	}
-	go rpc.StartHTTPServer(listener, mux, logger)
+	go rpc.StartHTTPServer(listener, mux, logger, config)
 	return listener
 }