diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/clientconn.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/clientconn.go | 427 |
1 files changed, 321 insertions, 106 deletions
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go index ae605bc32..bfbef3621 100644 --- a/vendor/google.golang.org/grpc/clientconn.go +++ b/vendor/google.golang.org/grpc/clientconn.go @@ -95,8 +95,14 @@ type dialOptions struct { scChan <-chan ServiceConfig copts transport.ConnectOptions callOptions []CallOption - // This is to support v1 balancer. + // This is used by v1 balancer dial option WithBalancer to support v1 + // balancer, and also by WithBalancerName dial option. balancerBuilder balancer.Builder + // This is to support grpclb. + resolverBuilder resolver.Builder + // Custom user options for resolver.Build. + resolverBuildUserOptions interface{} + waitForHandshake bool } const ( @@ -107,6 +113,15 @@ const ( // DialOption configures how we set up the connection. type DialOption func(*dialOptions) +// WithWaitForHandshake blocks until the initial settings frame is received from the +// server before assigning RPCs to the connection. +// Experimental API. +func WithWaitForHandshake() DialOption { + return func(o *dialOptions) { + o.waitForHandshake = true + } +} + // WithWriteBufferSize lets you set the size of write buffer, this determines how much data can be batched // before doing a write on the wire. func WithWriteBufferSize(s int) DialOption { @@ -186,7 +201,8 @@ func WithDecompressor(dc Decompressor) DialOption { // WithBalancer returns a DialOption which sets a load balancer with the v1 API. // Name resolver will be ignored if this DialOption is specified. -// Deprecated: use the new balancer APIs in balancer package instead. +// +// Deprecated: use the new balancer APIs in balancer package and WithBalancerName. func WithBalancer(b Balancer) DialOption { return func(o *dialOptions) { o.balancerBuilder = &balancerWrapperBuilder{ @@ -195,12 +211,36 @@ func WithBalancer(b Balancer) DialOption { } } -// WithBalancerBuilder is for testing only. Users using custom balancers should -// register their balancer and use service config to choose the balancer to use. -func WithBalancerBuilder(b balancer.Builder) DialOption { - // TODO(bar) remove this when switching balancer is done. +// WithBalancerName sets the balancer that the ClientConn will be initialized +// with. Balancer registered with balancerName will be used. This function +// panics if no balancer was registered by balancerName. +// +// The balancer cannot be overridden by balancer option specified by service +// config. +// +// This is an EXPERIMENTAL API. +func WithBalancerName(balancerName string) DialOption { + builder := balancer.Get(balancerName) + if builder == nil { + panic(fmt.Sprintf("grpc.WithBalancerName: no balancer is registered for name %v", balancerName)) + } + return func(o *dialOptions) { + o.balancerBuilder = builder + } +} + +// withResolverBuilder is only for grpclb. +func withResolverBuilder(b resolver.Builder) DialOption { return func(o *dialOptions) { - o.balancerBuilder = b + o.resolverBuilder = b + } +} + +// WithResolverUserOptions returns a DialOption which sets the UserOptions +// field of resolver's BuildOption. +func WithResolverUserOptions(userOpt interface{}) DialOption { + return func(o *dialOptions) { + o.resolverBuildUserOptions = userOpt } } @@ -231,7 +271,7 @@ func WithBackoffConfig(b BackoffConfig) DialOption { return withBackoff(b) } -// withBackoff sets the backoff strategy used for retries after a +// withBackoff sets the backoff strategy used for connectRetryNum after a // failed connection attempt. // // This can be exported if arbitrary backoff strategies are allowed by gRPC. @@ -283,18 +323,23 @@ func WithTimeout(d time.Duration) DialOption { } } +func withContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption { + return func(o *dialOptions) { + o.copts.Dialer = f + } +} + // WithDialer returns a DialOption that specifies a function to use for dialing network addresses. // If FailOnNonTempDialError() is set to true, and an error is returned by f, gRPC checks the error's // Temporary() method to decide if it should try to reconnect to the network address. func WithDialer(f func(string, time.Duration) (net.Conn, error)) DialOption { - return func(o *dialOptions) { - o.copts.Dialer = func(ctx context.Context, addr string) (net.Conn, error) { + return withContextDialer( + func(ctx context.Context, addr string) (net.Conn, error) { if deadline, ok := ctx.Deadline(); ok { return f(addr, deadline.Sub(time.Now())) } return f(addr, 0) - } - } + }) } // WithStatsHandler returns a DialOption that specifies the stats handler @@ -480,17 +525,19 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * Dialer: cc.dopts.copts.Dialer, } - if cc.dopts.balancerBuilder != nil { - cc.customBalancer = true - // Build should not take long time. So it's ok to not have a goroutine for it. - cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts) - } - // Build the resolver. cc.resolverWrapper, err = newCCResolverWrapper(cc) if err != nil { return nil, fmt.Errorf("failed to build resolver: %v", err) } + // Start the resolver wrapper goroutine after resolverWrapper is created. + // + // If the goroutine is started before resolverWrapper is ready, the + // following may happen: The goroutine sends updates to cc. cc forwards + // those to balancer. Balancer creates new addrConn. addrConn fails to + // connect, and calls resolveNow(). resolveNow() tries to use the non-ready + // resolverWrapper. + cc.resolverWrapper.start() // A blocking dial blocks until the clientConn is ready. if cc.dopts.block { @@ -563,7 +610,6 @@ type ClientConn struct { dopts dialOptions csMgr *connectivityStateManager - customBalancer bool // If this is true, switching balancer will be disabled. balancerBuildOpts balancer.BuildOptions resolverWrapper *ccResolverWrapper blockingpicker *pickerWrapper @@ -575,6 +621,7 @@ type ClientConn struct { // Keepalive parameter can be updated if a GoAway is received. mkp keepalive.ClientParameters curBalancerName string + preBalancerName string // previous balancer name. curAddresses []resolver.Address balancerWrapper *ccBalancerWrapper } @@ -624,51 +671,92 @@ func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) { cc.mu.Lock() defer cc.mu.Unlock() if cc.conns == nil { + // cc was closed. return } - // TODO(bar switching) when grpclb is submitted, check address type and start grpclb. - if !cc.customBalancer && cc.balancerWrapper == nil { - // No customBalancer was specified by DialOption, and this is the first - // time handling resolved addresses, create a pickfirst balancer. - builder := newPickfirstBuilder() - cc.curBalancerName = builder.Name() - cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts) + if reflect.DeepEqual(cc.curAddresses, addrs) { + return } - // TODO(bar switching) compare addresses, if there's no update, don't notify balancer. cc.curAddresses = addrs + + if cc.dopts.balancerBuilder == nil { + // Only look at balancer types and switch balancer if balancer dial + // option is not set. + var isGRPCLB bool + for _, a := range addrs { + if a.Type == resolver.GRPCLB { + isGRPCLB = true + break + } + } + var newBalancerName string + if isGRPCLB { + newBalancerName = grpclbName + } else { + // Address list doesn't contain grpclb address. Try to pick a + // non-grpclb balancer. + newBalancerName = cc.curBalancerName + // If current balancer is grpclb, switch to the previous one. + if newBalancerName == grpclbName { + newBalancerName = cc.preBalancerName + } + // The following could be true in two cases: + // - the first time handling resolved addresses + // (curBalancerName="") + // - the first time handling non-grpclb addresses + // (curBalancerName="grpclb", preBalancerName="") + if newBalancerName == "" { + newBalancerName = PickFirstBalancerName + } + } + cc.switchBalancer(newBalancerName) + } else if cc.balancerWrapper == nil { + // Balancer dial option was set, and this is the first time handling + // resolved addresses. Build a balancer with dopts.balancerBuilder. + cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts) + } + cc.balancerWrapper.handleResolvedAddrs(addrs, nil) } -// switchBalancer starts the switching from current balancer to the balancer with name. +// switchBalancer starts the switching from current balancer to the balancer +// with the given name. +// +// It will NOT send the current address list to the new balancer. If needed, +// caller of this function should send address list to the new balancer after +// this function returns. +// +// Caller must hold cc.mu. func (cc *ClientConn) switchBalancer(name string) { if cc.conns == nil { return } - grpclog.Infof("ClientConn switching balancer to %q", name) - if cc.customBalancer { - grpclog.Infoln("ignoring service config balancer configuration: WithBalancer DialOption used instead") + if strings.ToLower(cc.curBalancerName) == strings.ToLower(name) { return } - if cc.curBalancerName == name { + grpclog.Infof("ClientConn switching balancer to %q", name) + if cc.dopts.balancerBuilder != nil { + grpclog.Infoln("ignoring balancer switching: Balancer DialOption used instead") return } - // TODO(bar switching) change this to two steps: drain and close. // Keep track of sc in wrapper. - cc.balancerWrapper.close() + if cc.balancerWrapper != nil { + cc.balancerWrapper.close() + } builder := balancer.Get(name) if builder == nil { - grpclog.Infof("failed to get balancer builder for: %v (this should never happen...)", name) + grpclog.Infof("failed to get balancer builder for: %v, using pick_first instead", name) builder = newPickfirstBuilder() } + cc.preBalancerName = cc.curBalancerName cc.curBalancerName = builder.Name() cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts) - cc.balancerWrapper.handleResolvedAddrs(cc.curAddresses, nil) } func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) { @@ -684,6 +772,8 @@ func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivi } // newAddrConn creates an addrConn for addrs and adds it to cc.conns. +// +// Caller needs to make sure len(addrs) > 0. func (cc *ClientConn) newAddrConn(addrs []resolver.Address) (*addrConn, error) { ac := &addrConn{ cc: cc, @@ -774,6 +864,7 @@ func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool { grpclog.Infof("addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound) if curAddrFound { ac.addrs = addrs + ac.reconnectIdx = 0 // Start reconnecting from beginning in the new list. } return curAddrFound @@ -816,13 +907,33 @@ func (cc *ClientConn) handleServiceConfig(js string) error { cc.mu.Lock() cc.scRaw = js cc.sc = sc - if sc.LB != nil { - cc.switchBalancer(*sc.LB) + if sc.LB != nil && *sc.LB != grpclbName { // "grpclb" is not a valid balancer option in service config. + if cc.curBalancerName == grpclbName { + // If current balancer is grpclb, there's at least one grpclb + // balancer address in the resolved list. Don't switch the balancer, + // but change the previous balancer name, so if a new resolved + // address list doesn't contain grpclb address, balancer will be + // switched to *sc.LB. + cc.preBalancerName = *sc.LB + } else { + cc.switchBalancer(*sc.LB) + cc.balancerWrapper.handleResolvedAddrs(cc.curAddresses, nil) + } } cc.mu.Unlock() return nil } +func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) { + cc.mu.Lock() + r := cc.resolverWrapper + cc.mu.Unlock() + if r == nil { + return + } + go r.resolveNow(o) +} + // Close tears down the ClientConn and all underlying connections. func (cc *ClientConn) Close() error { cc.cancel() @@ -859,15 +970,16 @@ type addrConn struct { ctx context.Context cancel context.CancelFunc - cc *ClientConn - curAddr resolver.Address - addrs []resolver.Address - dopts dialOptions - events trace.EventLog - acbw balancer.SubConn + cc *ClientConn + addrs []resolver.Address + dopts dialOptions + events trace.EventLog + acbw balancer.SubConn - mu sync.Mutex - state connectivity.State + mu sync.Mutex + curAddr resolver.Address + reconnectIdx int // The index in addrs list to start reconnecting from. + state connectivity.State // ready is closed and becomes nil when a new transport is up or failed // due to timeout. ready chan struct{} @@ -875,6 +987,14 @@ type addrConn struct { // The reason this addrConn is torn down. tearDownErr error + + connectRetryNum int + // backoffDeadline is the time until which resetTransport needs to + // wait before increasing connectRetryNum count. + backoffDeadline time.Time + // connectDeadline is the time by which all connection + // negotiations must complete. + connectDeadline time.Time } // adjustParams updates parameters used to create transports upon @@ -909,6 +1029,15 @@ func (ac *addrConn) errorf(format string, a ...interface{}) { // resetTransport recreates a transport to the address for ac. The old // transport will close itself on error or when the clientconn is closed. +// The created transport must receive initial settings frame from the server. +// In case that doesnt happen, transportMonitor will kill the newly created +// transport after connectDeadline has expired. +// In case there was an error on the transport before the settings frame was +// received, resetTransport resumes connecting to backends after the one that +// was previously connected to. In case end of the list is reached, resetTransport +// backs off until the original deadline. +// If the DialOption WithWaitForHandshake was set, resetTrasport returns +// successfully only after server settings are received. // // TODO(bar) make sure all state transitions are valid. func (ac *addrConn) resetTransport() error { @@ -922,19 +1051,38 @@ func (ac *addrConn) resetTransport() error { ac.ready = nil } ac.transport = nil - ac.curAddr = resolver.Address{} + ridx := ac.reconnectIdx ac.mu.Unlock() ac.cc.mu.RLock() ac.dopts.copts.KeepaliveParams = ac.cc.mkp ac.cc.mu.RUnlock() - for retries := 0; ; retries++ { - sleepTime := ac.dopts.bs.backoff(retries) - timeout := minConnectTimeout + var backoffDeadline, connectDeadline time.Time + for connectRetryNum := 0; ; connectRetryNum++ { ac.mu.Lock() - if timeout < time.Duration(int(sleepTime)/len(ac.addrs)) { - timeout = time.Duration(int(sleepTime) / len(ac.addrs)) + if ac.backoffDeadline.IsZero() { + // This means either a successful HTTP2 connection was established + // or this is the first time this addrConn is trying to establish a + // connection. + backoffFor := ac.dopts.bs.backoff(connectRetryNum) // time.Duration. + // This will be the duration that dial gets to finish. + dialDuration := minConnectTimeout + if backoffFor > dialDuration { + // Give dial more time as we keep failing to connect. + dialDuration = backoffFor + } + start := time.Now() + backoffDeadline = start.Add(backoffFor) + connectDeadline = start.Add(dialDuration) + ridx = 0 // Start connecting from the beginning. + } else { + // Continue trying to conect with the same deadlines. + connectRetryNum = ac.connectRetryNum + backoffDeadline = ac.backoffDeadline + connectDeadline = ac.connectDeadline + ac.backoffDeadline = time.Time{} + ac.connectDeadline = time.Time{} + ac.connectRetryNum = 0 } - connectTime := time.Now() if ac.state == connectivity.Shutdown { ac.mu.Unlock() return errConnClosing @@ -949,93 +1097,159 @@ func (ac *addrConn) resetTransport() error { copy(addrsIter, ac.addrs) copts := ac.dopts.copts ac.mu.Unlock() - for _, addr := range addrsIter { + connected, err := ac.createTransport(connectRetryNum, ridx, backoffDeadline, connectDeadline, addrsIter, copts) + if err != nil { + return err + } + if connected { + return nil + } + } +} + +// createTransport creates a connection to one of the backends in addrs. +// It returns true if a connection was established. +func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline, connectDeadline time.Time, addrs []resolver.Address, copts transport.ConnectOptions) (bool, error) { + for i := ridx; i < len(addrs); i++ { + addr := addrs[i] + target := transport.TargetInfo{ + Addr: addr.Addr, + Metadata: addr.Metadata, + Authority: ac.cc.authority, + } + done := make(chan struct{}) + onPrefaceReceipt := func() { ac.mu.Lock() - if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - return errConnClosing + close(done) + if !ac.backoffDeadline.IsZero() { + // If we haven't already started reconnecting to + // other backends. + // Note, this can happen when writer notices an error + // and triggers resetTransport while at the same time + // reader receives the preface and invokes this closure. + ac.backoffDeadline = time.Time{} + ac.connectDeadline = time.Time{} + ac.connectRetryNum = 0 } ac.mu.Unlock() - sinfo := transport.TargetInfo{ - Addr: addr.Addr, - Metadata: addr.Metadata, - Authority: ac.cc.authority, - } - newTransport, err := transport.NewClientTransport(ac.cc.ctx, sinfo, copts, timeout) - if err != nil { - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - ac.mu.Lock() - if ac.state != connectivity.Shutdown { - ac.state = connectivity.TransientFailure - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - } - ac.mu.Unlock() - return err - } - grpclog.Warningf("grpc: addrConn.resetTransport failed to create client transport: %v; Reconnecting to %v", err, addr) + } + // Do not cancel in the success path because of + // this issue in Go1.6: https://github.com/golang/go/issues/15078. + connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline) + newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt) + if err != nil { + cancel() + if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { ac.mu.Lock() - if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - return errConnClosing + if ac.state != connectivity.Shutdown { + ac.state = connectivity.TransientFailure + ac.cc.handleSubConnStateChange(ac.acbw, ac.state) } ac.mu.Unlock() - continue + return false, err } ac.mu.Lock() - ac.printf("ready") if ac.state == connectivity.Shutdown { // ac.tearDown(...) has been invoked. ac.mu.Unlock() - newTransport.Close() - return errConnClosing - } - ac.state = connectivity.Ready - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - t := ac.transport - ac.transport = newTransport - if t != nil { - t.Close() - } - ac.curAddr = addr - if ac.ready != nil { - close(ac.ready) - ac.ready = nil + return false, errConnClosing } ac.mu.Unlock() - return nil + grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err) + continue + } + if ac.dopts.waitForHandshake { + select { + case <-done: + case <-connectCtx.Done(): + // Didn't receive server preface, must kill this new transport now. + grpclog.Warningf("grpc: addrConn.createTransport failed to receive server preface before deadline.") + newTr.Close() + break + case <-ac.ctx.Done(): + } } ac.mu.Lock() - ac.state = connectivity.TransientFailure + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + // ac.tearDonn(...) has been invoked. + newTr.Close() + return false, errConnClosing + } + ac.printf("ready") + ac.state = connectivity.Ready ac.cc.handleSubConnStateChange(ac.acbw, ac.state) + ac.transport = newTr + ac.curAddr = addr if ac.ready != nil { close(ac.ready) ac.ready = nil } - ac.mu.Unlock() - timer := time.NewTimer(sleepTime - time.Since(connectTime)) select { - case <-timer.C: - case <-ac.ctx.Done(): - timer.Stop() - return ac.ctx.Err() + case <-done: + // If the server has responded back with preface already, + // don't set the reconnect parameters. + default: + ac.connectRetryNum = connectRetryNum + ac.backoffDeadline = backoffDeadline + ac.connectDeadline = connectDeadline + ac.reconnectIdx = i + 1 // Start reconnecting from the next backend in the list. } + ac.mu.Unlock() + return true, nil + } + ac.mu.Lock() + ac.state = connectivity.TransientFailure + ac.cc.handleSubConnStateChange(ac.acbw, ac.state) + ac.cc.resolveNow(resolver.ResolveNowOption{}) + if ac.ready != nil { + close(ac.ready) + ac.ready = nil + } + ac.mu.Unlock() + timer := time.NewTimer(backoffDeadline.Sub(time.Now())) + select { + case <-timer.C: + case <-ac.ctx.Done(): timer.Stop() + return false, ac.ctx.Err() } + return false, nil } // Run in a goroutine to track the error in transport and create the // new transport if an error happens. It returns when the channel is closing. func (ac *addrConn) transportMonitor() { for { + var timer *time.Timer + var cdeadline <-chan time.Time ac.mu.Lock() t := ac.transport + if !ac.connectDeadline.IsZero() { + timer = time.NewTimer(ac.connectDeadline.Sub(time.Now())) + cdeadline = timer.C + } ac.mu.Unlock() // Block until we receive a goaway or an error occurs. select { case <-t.GoAway(): case <-t.Error(): + case <-cdeadline: + ac.mu.Lock() + // This implies that client received server preface. + if ac.backoffDeadline.IsZero() { + ac.mu.Unlock() + continue + } + ac.mu.Unlock() + timer = nil + // No server preface received until deadline. + // Kill the connection. + grpclog.Warningf("grpc: addrConn.transportMonitor didn't get server preface after waiting. Closing the new transport now.") + t.Close() + } + if timer != nil { + timer.Stop() } // If a GoAway happened, regardless of error, adjust our keepalive // parameters as appropriate. @@ -1053,6 +1267,7 @@ func (ac *addrConn) transportMonitor() { // resetTransport. Transition READY->CONNECTING is not valid. ac.state = connectivity.TransientFailure ac.cc.handleSubConnStateChange(ac.acbw, ac.state) + ac.cc.resolveNow(resolver.ResolveNowOption{}) ac.curAddr = resolver.Address{} ac.mu.Unlock() if err := ac.resetTransport(); err != nil { @@ -1140,6 +1355,9 @@ func (ac *addrConn) tearDown(err error) { ac.cancel() ac.mu.Lock() defer ac.mu.Unlock() + if ac.state == connectivity.Shutdown { + return + } ac.curAddr = resolver.Address{} if err == errConnDrain && ac.transport != nil { // GracefulClose(...) may be executed multiple times when @@ -1148,9 +1366,6 @@ func (ac *addrConn) tearDown(err error) { // address removal and GoAway. ac.transport.GracefulClose() } - if ac.state == connectivity.Shutdown { - return - } ac.state = connectivity.Shutdown ac.tearDownErr = err ac.cc.handleSubConnStateChange(ac.acbw, ac.state) |