From 107c1cdb09c575aa2f61d97f48d8587eb6bada4c Mon Sep 17 00:00:00 2001 From: Nathan Dench Date: Fri, 24 May 2019 15:16:44 +1000 Subject: Upgrade to 0.12 --- vendor/google.golang.org/grpc/clientconn.go | 1901 +++++++++++++++------------ 1 file changed, 1096 insertions(+), 805 deletions(-) (limited to 'vendor/google.golang.org/grpc/clientconn.go') diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go index e3f6cb1..56d0bf7 100644 --- a/vendor/google.golang.org/grpc/clientconn.go +++ b/vendor/google.golang.org/grpc/clientconn.go @@ -19,35 +19,72 @@ package grpc import ( + "context" "errors" + "fmt" + "math" "net" + "reflect" "strings" "sync" + "sync/atomic" "time" - "golang.org/x/net/context" - "golang.org/x/net/trace" + "google.golang.org/grpc/balancer" + _ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin. + "google.golang.org/grpc/codes" "google.golang.org/grpc/connectivity" "google.golang.org/grpc/credentials" "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/internal/backoff" + "google.golang.org/grpc/internal/channelz" + "google.golang.org/grpc/internal/envconfig" + "google.golang.org/grpc/internal/grpcsync" + "google.golang.org/grpc/internal/transport" "google.golang.org/grpc/keepalive" - "google.golang.org/grpc/stats" - "google.golang.org/grpc/transport" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/resolver" + _ "google.golang.org/grpc/resolver/dns" // To register dns resolver. + _ "google.golang.org/grpc/resolver/passthrough" // To register passthrough resolver. + "google.golang.org/grpc/status" +) + +const ( + // minimum time to give a connection to complete + minConnectTimeout = 20 * time.Second + // must match grpclbName in grpclb/grpclb.go + grpclbName = "grpclb" ) var ( // ErrClientConnClosing indicates that the operation is illegal because // the ClientConn is closing. - ErrClientConnClosing = errors.New("grpc: the client connection is closing") - // ErrClientConnTimeout indicates that the ClientConn cannot establish the - // underlying connections within the specified timeout. - // DEPRECATED: Please use context.DeadlineExceeded instead. - ErrClientConnTimeout = errors.New("grpc: timed out when dialing") + // + // Deprecated: this error should not be relied upon by users; use the status + // code of Canceled instead. + ErrClientConnClosing = status.Error(codes.Canceled, "grpc: the client connection is closing") + // errConnDrain indicates that the connection starts to be drained and does not accept any new RPCs. + errConnDrain = errors.New("grpc: the connection is drained") + // errConnClosing indicates that the connection is closing. + errConnClosing = errors.New("grpc: the connection is closing") + // errBalancerClosed indicates that the balancer is closed. + errBalancerClosed = errors.New("grpc: balancer is closed") + // We use an accessor so that minConnectTimeout can be + // atomically read and updated while testing. + getMinConnectTimeout = func() time.Duration { + return minConnectTimeout + } +) +// The following errors are returned from Dial and DialContext +var ( // errNoTransportSecurity indicates that there is no transport security // being set for ClientConn. Users should either set one or explicitly // call WithInsecure DialOption to disable security. errNoTransportSecurity = errors.New("grpc: no transport security set (use grpc.WithInsecure() explicitly or set credentials)") + // errTransportCredsAndBundle indicates that creds bundle is used together + // with other individual Transport Credentials. + errTransportCredsAndBundle = errors.New("grpc: credentials.Bundle may not be used with individual TransportCredentials") // errTransportCredentialsMissing indicates that users want to transmit security // information (e.g., oauth2 token) which requires secure connection on an insecure // connection. @@ -55,278 +92,100 @@ var ( // errCredentialsConflict indicates that grpc.WithTransportCredentials() // and grpc.WithInsecure() are both called for a connection. errCredentialsConflict = errors.New("grpc: transport credentials are set for an insecure connection (grpc.WithTransportCredentials() and grpc.WithInsecure() are both called)") - // errNetworkIO indicates that the connection is down due to some network I/O error. - errNetworkIO = errors.New("grpc: failed with network I/O error") - // errConnDrain indicates that the connection starts to be drained and does not accept any new RPCs. - errConnDrain = errors.New("grpc: the connection is drained") - // errConnClosing indicates that the connection is closing. - errConnClosing = errors.New("grpc: the connection is closing") - // errConnUnavailable indicates that the connection is unavailable. - errConnUnavailable = errors.New("grpc: the connection is unavailable") - // errBalancerClosed indicates that the balancer is closed. - errBalancerClosed = errors.New("grpc: balancer is closed") - // minimum time to give a connection to complete - minConnectTimeout = 20 * time.Second ) -// dialOptions configure a Dial call. dialOptions are set by the DialOption -// values passed to Dial. -type dialOptions struct { - unaryInt UnaryClientInterceptor - streamInt StreamClientInterceptor - codec Codec - cp Compressor - dc Decompressor - bs backoffStrategy - balancer Balancer - block bool - insecure bool - timeout time.Duration - scChan <-chan ServiceConfig - copts transport.ConnectOptions - callOptions []CallOption -} - const ( defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4 - defaultClientMaxSendMessageSize = 1024 * 1024 * 4 + defaultClientMaxSendMessageSize = math.MaxInt32 + // http2IOBufSize specifies the buffer size for sending frames. + defaultWriteBufSize = 32 * 1024 + defaultReadBufSize = 32 * 1024 ) -// DialOption configures how we set up the connection. -type DialOption func(*dialOptions) - -// WithInitialWindowSize returns a DialOption which sets the value for initial window size on a stream. -// The lower bound for window size is 64K and any value smaller than that will be ignored. -func WithInitialWindowSize(s int32) DialOption { - return func(o *dialOptions) { - o.copts.InitialWindowSize = s - } -} - -// WithInitialConnWindowSize returns a DialOption which sets the value for initial window size on a connection. -// The lower bound for window size is 64K and any value smaller than that will be ignored. -func WithInitialConnWindowSize(s int32) DialOption { - return func(o *dialOptions) { - o.copts.InitialConnWindowSize = s - } -} - -// WithMaxMsgSize returns a DialOption which sets the maximum message size the client can receive. Deprecated: use WithDefaultCallOptions(MaxCallRecvMsgSize(s)) instead. -func WithMaxMsgSize(s int) DialOption { - return WithDefaultCallOptions(MaxCallRecvMsgSize(s)) -} - -// WithDefaultCallOptions returns a DialOption which sets the default CallOptions for calls over the connection. -func WithDefaultCallOptions(cos ...CallOption) DialOption { - return func(o *dialOptions) { - o.callOptions = append(o.callOptions, cos...) - } -} - -// WithCodec returns a DialOption which sets a codec for message marshaling and unmarshaling. -func WithCodec(c Codec) DialOption { - return func(o *dialOptions) { - o.codec = c - } -} - -// WithCompressor returns a DialOption which sets a CompressorGenerator for generating message -// compressor. -func WithCompressor(cp Compressor) DialOption { - return func(o *dialOptions) { - o.cp = cp - } -} - -// WithDecompressor returns a DialOption which sets a DecompressorGenerator for generating -// message decompressor. -func WithDecompressor(dc Decompressor) DialOption { - return func(o *dialOptions) { - o.dc = dc - } -} - -// WithBalancer returns a DialOption which sets a load balancer. -func WithBalancer(b Balancer) DialOption { - return func(o *dialOptions) { - o.balancer = b - } -} - -// WithServiceConfig returns a DialOption which has a channel to read the service configuration. -func WithServiceConfig(c <-chan ServiceConfig) DialOption { - return func(o *dialOptions) { - o.scChan = c - } -} - -// WithBackoffMaxDelay configures the dialer to use the provided maximum delay -// when backing off after failed connection attempts. -func WithBackoffMaxDelay(md time.Duration) DialOption { - return WithBackoffConfig(BackoffConfig{MaxDelay: md}) -} - -// WithBackoffConfig configures the dialer to use the provided backoff -// parameters after connection failures. -// -// Use WithBackoffMaxDelay until more parameters on BackoffConfig are opened up -// for use. -func WithBackoffConfig(b BackoffConfig) DialOption { - // Set defaults to ensure that provided BackoffConfig is valid and - // unexported fields get default values. - setDefaults(&b) - return withBackoff(b) -} - -// withBackoff sets the backoff strategy used for retries after a -// failed connection attempt. -// -// This can be exported if arbitrary backoff strategies are allowed by gRPC. -func withBackoff(bs backoffStrategy) DialOption { - return func(o *dialOptions) { - o.bs = bs - } -} - -// WithBlock returns a DialOption which makes caller of Dial blocks until the underlying -// connection is up. Without this, Dial returns immediately and connecting the server -// happens in background. -func WithBlock() DialOption { - return func(o *dialOptions) { - o.block = true - } -} - -// WithInsecure returns a DialOption which disables transport security for this ClientConn. -// Note that transport security is required unless WithInsecure is set. -func WithInsecure() DialOption { - return func(o *dialOptions) { - o.insecure = true - } -} - -// WithTransportCredentials returns a DialOption which configures a -// connection level security credentials (e.g., TLS/SSL). -func WithTransportCredentials(creds credentials.TransportCredentials) DialOption { - return func(o *dialOptions) { - o.copts.TransportCredentials = creds - } -} - -// WithPerRPCCredentials returns a DialOption which sets -// credentials and places auth state on each outbound RPC. -func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption { - return func(o *dialOptions) { - o.copts.PerRPCCredentials = append(o.copts.PerRPCCredentials, creds) - } -} - -// WithTimeout returns a DialOption that configures a timeout for dialing a ClientConn -// initially. This is valid if and only if WithBlock() is present. -// Deprecated: use DialContext and context.WithTimeout instead. -func WithTimeout(d time.Duration) DialOption { - return func(o *dialOptions) { - o.timeout = d - } -} - -// 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) { - 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 -// for all the RPCs and underlying network connections in this ClientConn. -func WithStatsHandler(h stats.Handler) DialOption { - return func(o *dialOptions) { - o.copts.StatsHandler = h - } -} - -// FailOnNonTempDialError returns a DialOption that specifies if gRPC fails on non-temporary dial errors. -// If f is true, and dialer returns a non-temporary error, gRPC will fail the connection to the network -// address and won't try to reconnect. -// The default value of FailOnNonTempDialError is false. -// This is an EXPERIMENTAL API. -func FailOnNonTempDialError(f bool) DialOption { - return func(o *dialOptions) { - o.copts.FailOnNonTempDialError = f - } -} - -// WithUserAgent returns a DialOption that specifies a user agent string for all the RPCs. -func WithUserAgent(s string) DialOption { - return func(o *dialOptions) { - o.copts.UserAgent = s - } -} - -// WithKeepaliveParams returns a DialOption that specifies keepalive paramaters for the client transport. -func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption { - return func(o *dialOptions) { - o.copts.KeepaliveParams = kp - } -} - -// WithUnaryInterceptor returns a DialOption that specifies the interceptor for unary RPCs. -func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption { - return func(o *dialOptions) { - o.unaryInt = f - } -} - -// WithStreamInterceptor returns a DialOption that specifies the interceptor for streaming RPCs. -func WithStreamInterceptor(f StreamClientInterceptor) DialOption { - return func(o *dialOptions) { - o.streamInt = f - } -} - -// WithAuthority returns a DialOption that specifies the value to be used as -// the :authority pseudo-header. This value only works with WithInsecure and -// has no effect if TransportCredentials are present. -func WithAuthority(a string) DialOption { - return func(o *dialOptions) { - o.copts.Authority = a - } -} - // Dial creates a client connection to the given target. func Dial(target string, opts ...DialOption) (*ClientConn, error) { return DialContext(context.Background(), target, opts...) } -// DialContext creates a client connection to the given target. ctx can be used to -// cancel or expire the pending connection. Once this function returns, the -// cancellation and expiration of ctx will be noop. Users should call ClientConn.Close -// to terminate all the pending operations after this function returns. +// DialContext creates a client connection to the given target. By default, it's +// a non-blocking dial (the function won't wait for connections to be +// established, and connecting happens in the background). To make it a blocking +// dial, use WithBlock() dial option. +// +// In the non-blocking case, the ctx does not act against the connection. It +// only controls the setup steps. +// +// In the blocking case, ctx can be used to cancel or expire the pending +// connection. Once this function returns, the cancellation and expiration of +// ctx will be noop. Users should call ClientConn.Close to terminate all the +// pending operations after this function returns. +// +// The target name syntax is defined in +// https://github.com/grpc/grpc/blob/master/doc/naming.md. +// e.g. to use dns resolver, a "dns:///" prefix should be applied to the target. func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error) { cc := &ClientConn{ - target: target, - csMgr: &connectivityStateManager{}, - conns: make(map[Address]*addrConn), - } - cc.csEvltr = &connectivityStateEvaluator{csMgr: cc.csMgr} + target: target, + csMgr: &connectivityStateManager{}, + conns: make(map[*addrConn]struct{}), + dopts: defaultDialOptions(), + blockingpicker: newPickerWrapper(), + czData: new(channelzData), + firstResolveEvent: grpcsync.NewEvent(), + } + cc.retryThrottler.Store((*retryThrottler)(nil)) cc.ctx, cc.cancel = context.WithCancel(context.Background()) for _, opt := range opts { - opt(&cc.dopts) + opt.apply(&cc.dopts) + } + + if channelz.IsOn() { + if cc.dopts.channelzParentID != 0 { + cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target) + channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{ + Desc: "Channel Created", + Severity: channelz.CtINFO, + Parent: &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Nested Channel(id:%d) created", cc.channelzID), + Severity: channelz.CtINFO, + }, + }) + } else { + cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target) + channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{ + Desc: "Channel Created", + Severity: channelz.CtINFO, + }) + } + cc.csMgr.channelzID = cc.channelzID + } + + if !cc.dopts.insecure { + if cc.dopts.copts.TransportCredentials == nil && cc.dopts.copts.CredsBundle == nil { + return nil, errNoTransportSecurity + } + if cc.dopts.copts.TransportCredentials != nil && cc.dopts.copts.CredsBundle != nil { + return nil, errTransportCredsAndBundle + } + } else { + if cc.dopts.copts.TransportCredentials != nil || cc.dopts.copts.CredsBundle != nil { + return nil, errCredentialsConflict + } + for _, cd := range cc.dopts.copts.PerRPCCredentials { + if cd.RequireTransportSecurity() { + return nil, errTransportCredentialsMissing + } + } } + cc.mkp = cc.dopts.copts.KeepaliveParams if cc.dopts.copts.Dialer == nil { cc.dopts.copts.Dialer = newProxyDialer( func(ctx context.Context, addr string) (net.Conn, error) { - return dialContext(ctx, "tcp", addr) + network, addr := parseDialTarget(addr) + return (&net.Dialer{}).DialContext(ctx, network, addr) }, ) } @@ -367,66 +226,41 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * default: } } - // Set defaults. - if cc.dopts.codec == nil { - cc.dopts.codec = protoCodec{} - } if cc.dopts.bs == nil { - cc.dopts.bs = DefaultBackoffConfig + cc.dopts.bs = backoff.Exponential{ + MaxDelay: DefaultBackoffConfig.MaxDelay, + } + } + if cc.dopts.resolverBuilder == nil { + // Only try to parse target when resolver builder is not already set. + cc.parsedTarget = parseTarget(cc.target) + grpclog.Infof("parsed scheme: %q", cc.parsedTarget.Scheme) + cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme) + if cc.dopts.resolverBuilder == nil { + // If resolver builder is still nil, the parse target's scheme is + // not registered. Fallback to default resolver and set Endpoint to + // the original unparsed target. + grpclog.Infof("scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme) + cc.parsedTarget = resolver.Target{ + Scheme: resolver.GetDefaultScheme(), + Endpoint: target, + } + cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme) + } + } else { + cc.parsedTarget = resolver.Target{Endpoint: target} } creds := cc.dopts.copts.TransportCredentials if creds != nil && creds.Info().ServerName != "" { cc.authority = creds.Info().ServerName - } else if cc.dopts.insecure && cc.dopts.copts.Authority != "" { - cc.authority = cc.dopts.copts.Authority + } else if cc.dopts.insecure && cc.dopts.authority != "" { + cc.authority = cc.dopts.authority } else { - cc.authority = target - } - waitC := make(chan error, 1) - go func() { - defer close(waitC) - if cc.dopts.balancer == nil && cc.sc.LB != nil { - cc.dopts.balancer = cc.sc.LB - } - if cc.dopts.balancer != nil { - var credsClone credentials.TransportCredentials - if creds != nil { - credsClone = creds.Clone() - } - config := BalancerConfig{ - DialCreds: credsClone, - Dialer: cc.dopts.copts.Dialer, - } - if err := cc.dopts.balancer.Start(target, config); err != nil { - waitC <- err - return - } - ch := cc.dopts.balancer.Notify() - if ch != nil { - if cc.dopts.block { - doneChan := make(chan struct{}) - go cc.lbWatcher(doneChan) - <-doneChan - } else { - go cc.lbWatcher(nil) - } - return - } - } - // No balancer, or no resolver within the balancer. Connect directly. - if err := cc.resetAddrConn(Address{Addr: target}, cc.dopts.block, nil); err != nil { - waitC <- err - return - } - }() - select { - case <-ctx.Done(): - return nil, ctx.Err() - case err := <-waitC: - if err != nil { - return nil, err - } + // Use endpoint from "scheme://authority/endpoint" as the default + // authority for ClientConn. + cc.authority = cc.parsedTarget.Endpoint } + if cc.dopts.scChan != nil && !scSet { // Blocking wait for the initial service config. select { @@ -442,55 +276,50 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * go cc.scWatcher() } - return cc, nil -} + var credsClone credentials.TransportCredentials + if creds := cc.dopts.copts.TransportCredentials; creds != nil { + credsClone = creds.Clone() + } + cc.balancerBuildOpts = balancer.BuildOptions{ + DialCreds: credsClone, + CredsBundle: cc.dopts.copts.CredsBundle, + Dialer: cc.dopts.copts.Dialer, + ChannelzParentID: cc.channelzID, + } -// connectivityStateEvaluator gets updated by addrConns when their -// states transition, based on which it evaluates the state of -// ClientConn. -// Note: This code will eventually sit in the balancer in the new design. -type connectivityStateEvaluator struct { - csMgr *connectivityStateManager - mu sync.Mutex - numReady uint64 // Number of addrConns in ready state. - numConnecting uint64 // Number of addrConns in connecting state. - numTransientFailure uint64 // Number of addrConns in transientFailure. -} + // Build the resolver. + rWrapper, err := newCCResolverWrapper(cc) + if err != nil { + return nil, fmt.Errorf("failed to build resolver: %v", err) + } -// recordTransition records state change happening in every addrConn and based on -// that it evaluates what state the ClientConn is in. -// It can only transition between connectivity.Ready, connectivity.Connecting and connectivity.TransientFailure. Other states, -// Idle and connectivity.Shutdown are transitioned into by ClientConn; in the begining of the connection -// before any addrConn is created ClientConn is in idle state. In the end when ClientConn -// closes it is in connectivity.Shutdown state. -// TODO Note that in later releases, a ClientConn with no activity will be put into an Idle state. -func (cse *connectivityStateEvaluator) recordTransition(oldState, newState connectivity.State) { - cse.mu.Lock() - defer cse.mu.Unlock() - - // Update counters. - for idx, state := range []connectivity.State{oldState, newState} { - updateVal := 2*uint64(idx) - 1 // -1 for oldState and +1 for new. - switch state { - case connectivity.Ready: - cse.numReady += updateVal - case connectivity.Connecting: - cse.numConnecting += updateVal - case connectivity.TransientFailure: - cse.numTransientFailure += updateVal + cc.mu.Lock() + cc.resolverWrapper = rWrapper + cc.mu.Unlock() + // A blocking dial blocks until the clientConn is ready. + if cc.dopts.block { + for { + s := cc.GetState() + if s == connectivity.Ready { + break + } else if cc.dopts.copts.FailOnNonTempDialError && s == connectivity.TransientFailure { + if err = cc.blockingpicker.connectionError(); err != nil { + terr, ok := err.(interface { + Temporary() bool + }) + if ok && !terr.Temporary() { + return nil, err + } + } + } + if !cc.WaitForStateChange(ctx, s) { + // ctx got timeout or canceled. + return nil, ctx.Err() + } } } - // Evaluate. - if cse.numReady > 0 { - cse.csMgr.updateState(connectivity.Ready) - return - } - if cse.numConnecting > 0 { - cse.csMgr.updateState(connectivity.Connecting) - return - } - cse.csMgr.updateState(connectivity.TransientFailure) + return cc, nil } // connectivityStateManager keeps the connectivity.State of ClientConn. @@ -499,6 +328,7 @@ type connectivityStateManager struct { mu sync.Mutex state connectivity.State notifyChan chan struct{} + channelzID int64 } // updateState updates the connectivity.State of ClientConn. @@ -514,6 +344,12 @@ func (csm *connectivityStateManager) updateState(state connectivity.State) { return } csm.state = state + if channelz.IsOn() { + channelz.AddTraceEvent(csm.channelzID, &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Channel Connectivity change to %v", state), + Severity: channelz.CtINFO, + }) + } if csm.notifyChan != nil { // There are other goroutines waiting on this channel. close(csm.notifyChan) @@ -541,17 +377,32 @@ type ClientConn struct { ctx context.Context cancel context.CancelFunc - target string - authority string - dopts dialOptions - csMgr *connectivityStateManager - csEvltr *connectivityStateEvaluator // This will eventually be part of balancer. + target string + parsedTarget resolver.Target + authority string + dopts dialOptions + csMgr *connectivityStateManager + + balancerBuildOpts balancer.BuildOptions + blockingpicker *pickerWrapper - mu sync.RWMutex - sc ServiceConfig - conns map[Address]*addrConn + mu sync.RWMutex + resolverWrapper *ccResolverWrapper + sc ServiceConfig + scRaw string + conns map[*addrConn]struct{} // Keepalive parameter can be updated if a GoAway is received. - mkp keepalive.ClientParameters + mkp keepalive.ClientParameters + curBalancerName string + preBalancerName string // previous balancer name. + curAddresses []resolver.Address + balancerWrapper *ccBalancerWrapper + retryThrottler atomic.Value + + firstResolveEvent *grpcsync.Event + + channelzID int64 // channelz unique identification number + czData *channelzData } // WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or @@ -576,65 +427,6 @@ func (cc *ClientConn) GetState() connectivity.State { return cc.csMgr.getState() } -// lbWatcher watches the Notify channel of the balancer in cc and manages -// connections accordingly. If doneChan is not nil, it is closed after the -// first successfull connection is made. -func (cc *ClientConn) lbWatcher(doneChan chan struct{}) { - defer func() { - // In case channel from cc.dopts.balancer.Notify() gets closed before a - // successful connection gets established, don't forget to notify the - // caller. - if doneChan != nil { - close(doneChan) - } - }() - - for addrs := range cc.dopts.balancer.Notify() { - var ( - add []Address // Addresses need to setup connections. - del []*addrConn // Connections need to tear down. - ) - cc.mu.Lock() - for _, a := range addrs { - if _, ok := cc.conns[a]; !ok { - add = append(add, a) - } - } - for k, c := range cc.conns { - var keep bool - for _, a := range addrs { - if k == a { - keep = true - break - } - } - if !keep { - del = append(del, c) - delete(cc.conns, c.addr) - } - } - cc.mu.Unlock() - for _, a := range add { - var err error - if doneChan != nil { - err = cc.resetAddrConn(a, true, nil) - if err == nil { - close(doneChan) - doneChan = nil - } - } else { - err = cc.resetAddrConn(a, false, nil) - } - if err != nil { - grpclog.Warningf("Error creating connection to %v. Err: %v", a, err) - } - } - for _, c := range del { - c.tearDown(errConnDrain) - } - } -} - func (cc *ClientConn) scWatcher() { for { select { @@ -646,6 +438,7 @@ func (cc *ClientConn) scWatcher() { // TODO: load balance policy runtime change is ignored. // We may revist this decision in the future. cc.sc = sc + cc.scRaw = "" cc.mu.Unlock() case <-cc.ctx.Done(): return @@ -653,169 +446,411 @@ func (cc *ClientConn) scWatcher() { } } -// resetAddrConn creates an addrConn for addr and adds it to cc.conns. -// If there is an old addrConn for addr, it will be torn down, using tearDownErr as the reason. -// If tearDownErr is nil, errConnDrain will be used instead. -// -// We should never need to replace an addrConn with a new one. This function is only used -// as newAddrConn to create new addrConn. -// TODO rename this function and clean up the code. -func (cc *ClientConn) resetAddrConn(addr Address, block bool, tearDownErr error) error { - ac := &addrConn{ - cc: cc, - addr: addr, - dopts: cc.dopts, - } - ac.ctx, ac.cancel = context.WithCancel(cc.ctx) - ac.csEvltr = cc.csEvltr - if EnableTracing { - ac.events = trace.NewEventLog("grpc.ClientConn", ac.addr.Addr) +// waitForResolvedAddrs blocks until the resolver has provided addresses or the +// context expires. Returns nil unless the context expires first; otherwise +// returns a status error based on the context. +func (cc *ClientConn) waitForResolvedAddrs(ctx context.Context) error { + // This is on the RPC path, so we use a fast path to avoid the + // more-expensive "select" below after the resolver has returned once. + if cc.firstResolveEvent.HasFired() { + return nil } - if !ac.dopts.insecure { - if ac.dopts.copts.TransportCredentials == nil { - return errNoTransportSecurity - } - } else { - if ac.dopts.copts.TransportCredentials != nil { - return errCredentialsConflict - } - for _, cd := range ac.dopts.copts.PerRPCCredentials { - if cd.RequireTransportSecurity() { - return errTransportCredentialsMissing - } - } + select { + case <-cc.firstResolveEvent.Done(): + return nil + case <-ctx.Done(): + return status.FromContextError(ctx.Err()).Err() + case <-cc.ctx.Done(): + return ErrClientConnClosing } - // Track ac in cc. This needs to be done before any getTransport(...) is called. +} + +func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) { cc.mu.Lock() + defer cc.mu.Unlock() if cc.conns == nil { - cc.mu.Unlock() - return ErrClientConnClosing + // cc was closed. + return } - stale := cc.conns[ac.addr] - cc.conns[ac.addr] = ac - cc.mu.Unlock() - if stale != nil { - // There is an addrConn alive on ac.addr already. This could be due to - // a buggy Balancer that reports duplicated Addresses. - if tearDownErr == nil { - // tearDownErr is nil if resetAddrConn is called by - // 1) Dial - // 2) lbWatcher - // In both cases, the stale ac should drain, not close. - stale.tearDown(errConnDrain) - } else { - stale.tearDown(tearDownErr) - } + + if reflect.DeepEqual(cc.curAddresses, addrs) { + return } - if block { - if err := ac.resetTransport(false); err != nil { - if err != errConnClosing { - // Tear down ac and delete it from cc.conns. - cc.mu.Lock() - delete(cc.conns, ac.addr) - cc.mu.Unlock() - ac.tearDown(err) - } - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return e.Origin() + + cc.curAddresses = addrs + cc.firstResolveEvent.Fire() + + 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 } - return err } - // Start to monitor the error status of transport. - go ac.transportMonitor() - } else { - // Start a goroutine connecting to the server asynchronously. - go func() { - if err := ac.resetTransport(false); err != nil { - grpclog.Warningf("Failed to dial %s: %v; please retry.", ac.addr.Addr, err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) - } - return + 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 } - ac.transportMonitor() - }() + // 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) } - return nil + + cc.balancerWrapper.handleResolvedAddrs(addrs, nil) } -// GetMethodConfig gets the method config of the input method. -// If there's an exact match for input method (i.e. /service/method), we return -// the corresponding MethodConfig. -// If there isn't an exact match for the input method, we look for the default config -// under the service (i.e /service/). If there is a default MethodConfig for -// the serivce, we return it. -// Otherwise, we return an empty MethodConfig. -func (cc *ClientConn) GetMethodConfig(method string) MethodConfig { - // TODO: Avoid the locking here. - cc.mu.RLock() - defer cc.mu.RUnlock() - m, ok := cc.sc.Methods[method] - if !ok { - i := strings.LastIndex(method, "/") - m, _ = cc.sc.Methods[method[:i+1]] +// 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 } - return m -} -func (cc *ClientConn) getTransport(ctx context.Context, opts BalancerGetOptions) (transport.ClientTransport, func(), error) { - var ( - ac *addrConn - ok bool - put func() - ) - if cc.dopts.balancer == nil { - // If balancer is nil, there should be only one addrConn available. - cc.mu.RLock() - if cc.conns == nil { - cc.mu.RUnlock() - return nil, nil, toRPCErr(ErrClientConnClosing) - } - for _, ac = range cc.conns { - // Break after the first iteration to get the first addrConn. - ok = true - break - } - cc.mu.RUnlock() - } else { - var ( - addr Address - err error - ) - addr, put, err = cc.dopts.balancer.Get(ctx, opts) - if err != nil { - return nil, nil, toRPCErr(err) - } - cc.mu.RLock() - if cc.conns == nil { - cc.mu.RUnlock() - return nil, nil, toRPCErr(ErrClientConnClosing) - } - ac, ok = cc.conns[addr] - cc.mu.RUnlock() + if strings.ToLower(cc.curBalancerName) == strings.ToLower(name) { + return } - if !ok { - if put != nil { - updateRPCInfoInContext(ctx, rpcInfo{bytesSent: false, bytesReceived: false}) - put() - } - return nil, nil, errConnClosing + + grpclog.Infof("ClientConn switching balancer to %q", name) + if cc.dopts.balancerBuilder != nil { + grpclog.Infoln("ignoring balancer switching: Balancer DialOption used instead") + return } - t, err := ac.wait(ctx, cc.dopts.balancer != nil, !opts.BlockingWait) + // TODO(bar switching) change this to two steps: drain and close. + // Keep track of sc in wrapper. + if cc.balancerWrapper != nil { + cc.balancerWrapper.close() + } + + builder := balancer.Get(name) + // TODO(yuxuanli): If user send a service config that does not contain a valid balancer name, should + // we reuse previous one? + if channelz.IsOn() { + if builder == nil { + channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName), + Severity: channelz.CtWarning, + }) + } else { + channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Channel switches to new LB policy %q", name), + Severity: channelz.CtINFO, + }) + } + } + if builder == nil { + 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) +} + +func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) { + cc.mu.Lock() + if cc.conns == nil { + cc.mu.Unlock() + return + } + // TODO(bar switching) send updates to all balancer wrappers when balancer + // gracefully switching is supported. + cc.balancerWrapper.handleSubConnStateChange(sc, s) + cc.mu.Unlock() +} + +// 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, opts balancer.NewSubConnOptions) (*addrConn, error) { + ac := &addrConn{ + cc: cc, + addrs: addrs, + scopts: opts, + dopts: cc.dopts, + czData: new(channelzData), + resetBackoff: make(chan struct{}), + } + ac.ctx, ac.cancel = context.WithCancel(cc.ctx) + // Track ac in cc. This needs to be done before any getTransport(...) is called. + cc.mu.Lock() + if cc.conns == nil { + cc.mu.Unlock() + return nil, ErrClientConnClosing + } + if channelz.IsOn() { + ac.channelzID = channelz.RegisterSubChannel(ac, cc.channelzID, "") + channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{ + Desc: "Subchannel Created", + Severity: channelz.CtINFO, + Parent: &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Subchannel(id:%d) created", ac.channelzID), + Severity: channelz.CtINFO, + }, + }) + } + cc.conns[ac] = struct{}{} + cc.mu.Unlock() + return ac, nil +} + +// removeAddrConn removes the addrConn in the subConn from clientConn. +// It also tears down the ac with the given error. +func (cc *ClientConn) removeAddrConn(ac *addrConn, err error) { + cc.mu.Lock() + if cc.conns == nil { + cc.mu.Unlock() + return + } + delete(cc.conns, ac) + cc.mu.Unlock() + ac.tearDown(err) +} + +func (cc *ClientConn) channelzMetric() *channelz.ChannelInternalMetric { + return &channelz.ChannelInternalMetric{ + State: cc.GetState(), + Target: cc.target, + CallsStarted: atomic.LoadInt64(&cc.czData.callsStarted), + CallsSucceeded: atomic.LoadInt64(&cc.czData.callsSucceeded), + CallsFailed: atomic.LoadInt64(&cc.czData.callsFailed), + LastCallStartedTimestamp: time.Unix(0, atomic.LoadInt64(&cc.czData.lastCallStartedTime)), + } +} + +// Target returns the target string of the ClientConn. +// This is an EXPERIMENTAL API. +func (cc *ClientConn) Target() string { + return cc.target +} + +func (cc *ClientConn) incrCallsStarted() { + atomic.AddInt64(&cc.czData.callsStarted, 1) + atomic.StoreInt64(&cc.czData.lastCallStartedTime, time.Now().UnixNano()) +} + +func (cc *ClientConn) incrCallsSucceeded() { + atomic.AddInt64(&cc.czData.callsSucceeded, 1) +} + +func (cc *ClientConn) incrCallsFailed() { + atomic.AddInt64(&cc.czData.callsFailed, 1) +} + +// connect starts creating a transport. +// It does nothing if the ac is not IDLE. +// TODO(bar) Move this to the addrConn section. +func (ac *addrConn) connect() error { + ac.mu.Lock() + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + return errConnClosing + } + if ac.state != connectivity.Idle { + ac.mu.Unlock() + return nil + } + ac.updateConnectivityState(connectivity.Connecting) + ac.mu.Unlock() + + // Start a goroutine connecting to the server asynchronously. + go ac.resetTransport() + return nil +} + +// tryUpdateAddrs tries to update ac.addrs with the new addresses list. +// +// It checks whether current connected address of ac is in the new addrs list. +// - If true, it updates ac.addrs and returns true. The ac will keep using +// the existing connection. +// - If false, it does nothing and returns false. +func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool { + ac.mu.Lock() + defer ac.mu.Unlock() + grpclog.Infof("addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs) + if ac.state == connectivity.Shutdown { + ac.addrs = addrs + return true + } + + // Unless we're busy reconnecting already, let's reconnect from the top of + // the list. + if ac.state != connectivity.Ready { + return false + } + + var curAddrFound bool + for _, a := range addrs { + if reflect.DeepEqual(ac.curAddr, a) { + curAddrFound = true + break + } + } + grpclog.Infof("addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound) + if curAddrFound { + ac.addrs = addrs + } + + return curAddrFound +} + +// GetMethodConfig gets the method config of the input method. +// If there's an exact match for input method (i.e. /service/method), we return +// the corresponding MethodConfig. +// If there isn't an exact match for the input method, we look for the default config +// under the service (i.e /service/). If there is a default MethodConfig for +// the service, we return it. +// Otherwise, we return an empty MethodConfig. +func (cc *ClientConn) GetMethodConfig(method string) MethodConfig { + // TODO: Avoid the locking here. + cc.mu.RLock() + defer cc.mu.RUnlock() + m, ok := cc.sc.Methods[method] + if !ok { + i := strings.LastIndex(method, "/") + m = cc.sc.Methods[method[:i+1]] + } + return m +} + +func (cc *ClientConn) healthCheckConfig() *healthCheckConfig { + cc.mu.RLock() + defer cc.mu.RUnlock() + return cc.sc.healthCheckConfig +} + +func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) { + hdr, _ := metadata.FromOutgoingContext(ctx) + t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickOptions{ + FullMethodName: method, + Header: hdr, + }) if err != nil { - if put != nil { - updateRPCInfoInContext(ctx, rpcInfo{bytesSent: false, bytesReceived: false}) - put() + return nil, nil, toRPCErr(err) + } + return t, done, nil +} + +// handleServiceConfig parses the service config string in JSON format to Go native +// struct ServiceConfig, and store both the struct and the JSON string in ClientConn. +func (cc *ClientConn) handleServiceConfig(js string) error { + if cc.dopts.disableServiceConfig { + return nil + } + if cc.scRaw == js { + return nil + } + if channelz.IsOn() { + channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{ + // The special formatting of \"%s\" instead of %q is to provide nice printing of service config + // for human consumption. + Desc: fmt.Sprintf("Channel has a new service config \"%s\"", js), + Severity: channelz.CtINFO, + }) + } + sc, err := parseServiceConfig(js) + if err != nil { + return err + } + cc.mu.Lock() + // Check if the ClientConn is already closed. Some fields (e.g. + // balancerWrapper) are set to nil when closing the ClientConn, and could + // cause nil pointer panic if we don't have this check. + if cc.conns == nil { + cc.mu.Unlock() + return nil + } + cc.scRaw = js + cc.sc = sc + + if sc.retryThrottling != nil { + newThrottler := &retryThrottler{ + tokens: sc.retryThrottling.MaxTokens, + max: sc.retryThrottling.MaxTokens, + thresh: sc.retryThrottling.MaxTokens / 2, + ratio: sc.retryThrottling.TokenRatio, + } + cc.retryThrottler.Store(newThrottler) + } else { + cc.retryThrottler.Store((*retryThrottler)(nil)) + } + + 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) } - return nil, nil, err } - return t, put, nil + + cc.mu.Unlock() + return nil +} + +func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) { + cc.mu.RLock() + r := cc.resolverWrapper + cc.mu.RUnlock() + if r == nil { + return + } + go r.resolveNow(o) +} + +// ResetConnectBackoff wakes up all subchannels in transient failure and causes +// them to attempt another connection immediately. It also resets the backoff +// times used for subsequent attempts regardless of the current state. +// +// In general, this function should not be used. Typical service or network +// outages result in a reasonable client reconnection strategy by default. +// However, if a previously unavailable network becomes available, this may be +// used to trigger an immediate reconnect. +// +// This API is EXPERIMENTAL. +func (cc *ClientConn) ResetConnectBackoff() { + cc.mu.Lock() + defer cc.mu.Unlock() + for ac := range cc.conns { + ac.resetConnectBackoff() + } } // Close tears down the ClientConn and all underlying connections. func (cc *ClientConn) Close() error { - cc.cancel() + defer cc.cancel() cc.mu.Lock() if cc.conns == nil { @@ -825,13 +860,41 @@ func (cc *ClientConn) Close() error { conns := cc.conns cc.conns = nil cc.csMgr.updateState(connectivity.Shutdown) + + rWrapper := cc.resolverWrapper + cc.resolverWrapper = nil + bWrapper := cc.balancerWrapper + cc.balancerWrapper = nil cc.mu.Unlock() - if cc.dopts.balancer != nil { - cc.dopts.balancer.Close() + + cc.blockingpicker.close() + + if rWrapper != nil { + rWrapper.close() + } + if bWrapper != nil { + bWrapper.close() } - for _, ac := range conns { + + for ac := range conns { ac.tearDown(ErrClientConnClosing) } + if channelz.IsOn() { + ted := &channelz.TraceEventDesc{ + Desc: "Channel Deleted", + Severity: channelz.CtINFO, + } + if cc.dopts.channelzParentID != 0 { + ted.Parent = &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Nested channel(id:%d) deleted", cc.channelzID), + Severity: channelz.CtINFO, + } + } + channelz.AddTraceEvent(cc.channelzID, ted) + // TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to + // the entity beng deleted, and thus prevent it from being deleted right away. + channelz.RemoveEntry(cc.channelzID) + } return nil } @@ -841,29 +904,56 @@ type addrConn struct { cancel context.CancelFunc cc *ClientConn - addr Address dopts dialOptions - events trace.EventLog + acbw balancer.SubConn + scopts balancer.NewSubConnOptions + + // transport is set when there's a viable transport (note: ac state may not be READY as LB channel + // health checking may require server to report healthy to set ac to READY), and is reset + // to nil when the current transport should no longer be used to create a stream (e.g. after GoAway + // is received, transport is closed, ac has been torn down). + transport transport.ClientTransport // The current transport. - csEvltr *connectivityStateEvaluator + mu sync.Mutex + curAddr resolver.Address // The current address. + addrs []resolver.Address // All addresses that the resolver resolved to. - mu sync.Mutex + // Use updateConnectivityState for updating addrConn's connectivity state. state connectivity.State - down func(error) // the handler called when a connection is down. - // ready is closed and becomes nil when a new transport is up or failed - // due to timeout. - ready chan struct{} - transport transport.ClientTransport - - // The reason this addrConn is torn down. - tearDownErr error + + tearDownErr error // The reason this addrConn is torn down. + + backoffIdx int // Needs to be stateful for resetConnectBackoff. + resetBackoff chan struct{} + + channelzID int64 // channelz unique identification number. + czData *channelzData + healthCheckEnabled bool +} + +// Note: this requires a lock on ac.mu. +func (ac *addrConn) updateConnectivityState(s connectivity.State) { + if ac.state == s { + return + } + + updateMsg := fmt.Sprintf("Subchannel Connectivity change to %v", s) + grpclog.Infof(updateMsg) + ac.state = s + if channelz.IsOn() { + channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{ + Desc: updateMsg, + Severity: channelz.CtINFO, + }) + } + ac.cc.handleSubConnStateChange(ac.acbw, s) } // adjustParams updates parameters used to create transports upon // receiving a GoAway. func (ac *addrConn) adjustParams(r transport.GoAwayReason) { switch r { - case transport.TooManyPings: + case transport.GoAwayTooManyPings: v := 2 * ac.dopts.copts.KeepaliveParams.Time ac.cc.mu.Lock() if v > ac.cc.mkp.Time { @@ -873,246 +963,359 @@ func (ac *addrConn) adjustParams(r transport.GoAwayReason) { } } -// printf records an event in ac's event log, unless ac has been closed. -// REQUIRES ac.mu is held. -func (ac *addrConn) printf(format string, a ...interface{}) { - if ac.events != nil { - ac.events.Printf(format, a...) - } -} +func (ac *addrConn) resetTransport() { + for i := 0; ; i++ { + tryNextAddrFromStart := grpcsync.NewEvent() -// errorf records an error in ac's event log, unless ac has been closed. -// REQUIRES ac.mu is held. -func (ac *addrConn) errorf(format string, a ...interface{}) { - if ac.events != nil { - ac.events.Errorf(format, a...) - } -} - -// resetTransport recreates a transport to the address for ac. -// For the old transport: -// - if drain is true, it will be gracefully closed. -// - otherwise, it will be closed. -func (ac *addrConn) resetTransport(drain bool) error { - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return errConnClosing - } - ac.printf("connecting") - if ac.down != nil { - ac.down(downErrorf(false, true, "%v", errNetworkIO)) - ac.down = nil - } - oldState := ac.state - ac.state = connectivity.Connecting - ac.csEvltr.recordTransition(oldState, ac.state) - t := ac.transport - ac.transport = nil - ac.mu.Unlock() - if t != nil && !drain { - t.Close() - } - ac.cc.mu.RLock() - ac.dopts.copts.KeepaliveParams = ac.cc.mkp - ac.cc.mu.RUnlock() - for retries := 0; ; retries++ { ac.mu.Lock() - if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - return errConnClosing + if i > 0 { + ac.cc.resolveNow(resolver.ResolveNowOption{}) } + addrs := ac.addrs + backoffFor := ac.dopts.bs.Backoff(ac.backoffIdx) ac.mu.Unlock() - sleepTime := ac.dopts.bs.backoff(retries) - timeout := minConnectTimeout - if timeout < sleepTime { - timeout = sleepTime - } - ctx, cancel := context.WithTimeout(ac.ctx, timeout) - connectTime := time.Now() - sinfo := transport.TargetInfo{ - Addr: ac.addr.Addr, - Metadata: ac.addr.Metadata, - } - newTransport, err := transport.NewClientTransport(ctx, sinfo, ac.dopts.copts) - // Don't call cancel in success path due to a race in Go 1.6: - // https://github.com/golang/go/issues/15078. - if err != nil { - cancel() - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return err + addrLoop: + for _, addr := range addrs { + ac.mu.Lock() + + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + return } - grpclog.Warningf("grpc: addrConn.resetTransport failed to create client transport: %v; Reconnecting to %v", err, ac.addr) + ac.updateConnectivityState(connectivity.Connecting) + ac.transport = nil + ac.mu.Unlock() + + // This will be the duration that dial gets to finish. + dialDuration := getMinConnectTimeout() + if dialDuration < backoffFor { + // Give dial more time as we keep failing to connect. + dialDuration = backoffFor + } + connectDeadline := time.Now().Add(dialDuration) + ac.mu.Lock() + ac.cc.mu.RLock() + ac.dopts.copts.KeepaliveParams = ac.cc.mkp + ac.cc.mu.RUnlock() + if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. ac.mu.Unlock() - return errConnClosing + return } - ac.errorf("transient failure: %v", err) - oldState = ac.state - ac.state = connectivity.TransientFailure - ac.csEvltr.recordTransition(oldState, ac.state) - if ac.ready != nil { - close(ac.ready) - ac.ready = nil + + copts := ac.dopts.copts + if ac.scopts.CredsBundle != nil { + copts.CredsBundle = ac.scopts.CredsBundle } + hctx, hcancel := context.WithCancel(ac.ctx) + defer hcancel() ac.mu.Unlock() - timer := time.NewTimer(sleepTime - time.Since(connectTime)) - select { - case <-timer.C: - case <-ac.ctx.Done(): - timer.Stop() - return ac.ctx.Err() + + if channelz.IsOn() { + channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Subchannel picks a new address %q to connect", addr.Addr), + Severity: channelz.CtINFO, + }) + } + + reconnect := grpcsync.NewEvent() + prefaceReceived := make(chan struct{}) + newTr, err := ac.createTransport(addr, copts, connectDeadline, reconnect, prefaceReceived) + if err == nil { + ac.mu.Lock() + ac.curAddr = addr + ac.transport = newTr + ac.mu.Unlock() + + healthCheckConfig := ac.cc.healthCheckConfig() + // LB channel health checking is only enabled when all the four requirements below are met: + // 1. it is not disabled by the user with the WithDisableHealthCheck DialOption, + // 2. the internal.HealthCheckFunc is set by importing the grpc/healthcheck package, + // 3. a service config with non-empty healthCheckConfig field is provided, + // 4. the current load balancer allows it. + healthcheckManagingState := false + if !ac.cc.dopts.disableHealthCheck && healthCheckConfig != nil && ac.scopts.HealthCheckEnabled { + if ac.cc.dopts.healthCheckFunc == nil { + // TODO: add a link to the health check doc in the error message. + grpclog.Error("the client side LB channel health check function has not been set.") + } else { + // TODO(deklerk) refactor to just return transport + go ac.startHealthCheck(hctx, newTr, addr, healthCheckConfig.ServiceName) + healthcheckManagingState = true + } + } + if !healthcheckManagingState { + ac.mu.Lock() + ac.updateConnectivityState(connectivity.Ready) + ac.mu.Unlock() + } + } else { + hcancel() + if err == errConnClosing { + return + } + + if tryNextAddrFromStart.HasFired() { + break addrLoop + } + continue + } + + ac.mu.Lock() + reqHandshake := ac.dopts.reqHandshake + ac.mu.Unlock() + + <-reconnect.Done() + hcancel() + + if reqHandshake == envconfig.RequireHandshakeHybrid { + // In RequireHandshakeHybrid mode, we must check to see whether + // server preface has arrived yet to decide whether to start + // reconnecting at the top of the list (server preface received) + // or continue with the next addr in the list as if the + // connection were not successful (server preface not received). + select { + case <-prefaceReceived: + // We received a server preface - huzzah! We consider this + // a success and restart from the top of the addr list. + ac.mu.Lock() + ac.backoffIdx = 0 + ac.mu.Unlock() + break addrLoop + default: + // Despite having set state to READY, in hybrid mode we + // consider this a failure and continue connecting at the + // next addr in the list. + ac.mu.Lock() + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + return + } + + ac.updateConnectivityState(connectivity.TransientFailure) + ac.mu.Unlock() + + if tryNextAddrFromStart.HasFired() { + break addrLoop + } + } + } else { + // In RequireHandshakeOn mode, we would have already waited for + // the server preface, so we consider this a success and restart + // from the top of the addr list. In RequireHandshakeOff mode, + // we don't care to wait for the server preface before + // considering this a success, so we also restart from the top + // of the addr list. + ac.mu.Lock() + ac.backoffIdx = 0 + ac.mu.Unlock() + break addrLoop } - timer.Stop() - continue } + + // After exhausting all addresses, or after need to reconnect after a + // READY, the addrConn enters TRANSIENT_FAILURE. ac.mu.Lock() - ac.printf("ready") if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. ac.mu.Unlock() - newTransport.Close() - return errConnClosing - } - oldState = ac.state - ac.state = connectivity.Ready - ac.csEvltr.recordTransition(oldState, ac.state) - ac.transport = newTransport - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - if ac.cc.dopts.balancer != nil { - ac.down = ac.cc.dopts.balancer.Up(ac.addr) + return } + ac.updateConnectivityState(connectivity.TransientFailure) + + // Backoff. + b := ac.resetBackoff + timer := time.NewTimer(backoffFor) + acctx := ac.ctx ac.mu.Unlock() - return nil + + select { + case <-timer.C: + ac.mu.Lock() + ac.backoffIdx++ + ac.mu.Unlock() + case <-b: + timer.Stop() + case <-acctx.Done(): + timer.Stop() + return + } } } -// 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 { +// createTransport creates a connection to one of the backends in addrs. It +// sets ac.transport in the success case, or it returns an error if it was +// unable to successfully create a transport. +// +// If waitForHandshake is enabled, it blocks until server preface arrives. +func (ac *addrConn) createTransport(addr resolver.Address, copts transport.ConnectOptions, connectDeadline time.Time, reconnect *grpcsync.Event, prefaceReceived chan struct{}) (transport.ClientTransport, error) { + onCloseCalled := make(chan struct{}) + + target := transport.TargetInfo{ + Addr: addr.Addr, + Metadata: addr.Metadata, + Authority: ac.cc.authority, + } + + prefaceTimer := time.NewTimer(connectDeadline.Sub(time.Now())) + + onGoAway := func(r transport.GoAwayReason) { ac.mu.Lock() - t := ac.transport + ac.adjustParams(r) ac.mu.Unlock() - select { - // This is needed to detect the teardown when - // the addrConn is idle (i.e., no RPC in flight). - case <-ac.ctx.Done(): - select { - case <-t.Error(): - t.Close() - default: - } - return - case <-t.GoAway(): - ac.adjustParams(t.GetGoAwayReason()) - // If GoAway happens without any network I/O error, the underlying transport - // will be gracefully closed, and a new transport will be created. - // (The transport will be closed when all the pending RPCs finished or failed.) - // If GoAway and some network I/O error happen concurrently, the underlying transport - // will be closed, and a new transport will be created. - var drain bool - select { - case <-t.Error(): - default: - drain = true - } - if err := ac.resetTransport(drain); err != nil { - grpclog.Infof("get error from resetTransport %v, transportMonitor returning", err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) - } - return - } - case <-t.Error(): + reconnect.Fire() + } + + onClose := func() { + close(onCloseCalled) + prefaceTimer.Stop() + reconnect.Fire() + } + + onPrefaceReceipt := func() { + close(prefaceReceived) + prefaceTimer.Stop() + } + + connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline) + defer cancel() + if channelz.IsOn() { + copts.ChannelzParentID = ac.channelzID + } + + newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt, onGoAway, onClose) + + if err == nil { + if ac.dopts.reqHandshake == envconfig.RequireHandshakeOn { select { - case <-ac.ctx.Done(): - t.Close() - return - case <-t.GoAway(): - ac.adjustParams(t.GetGoAwayReason()) - if err := ac.resetTransport(false); err != nil { - grpclog.Infof("get error from resetTransport %v, transportMonitor returning", err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) - } - return - } - default: - } - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - // ac has been shutdown. - ac.mu.Unlock() - return + case <-prefaceTimer.C: + // We didn't get the preface in time. + newTr.Close() + err = errors.New("timed out waiting for server handshake") + case <-prefaceReceived: + // We got the preface - huzzah! things are good. + case <-onCloseCalled: + // The transport has already closed - noop. + return nil, errors.New("connection closed") } - oldState := ac.state - ac.state = connectivity.TransientFailure - ac.csEvltr.recordTransition(oldState, ac.state) - ac.mu.Unlock() - if err := ac.resetTransport(false); err != nil { - grpclog.Infof("get error from resetTransport %v, transportMonitor returning", err) - ac.mu.Lock() - ac.printf("transport exiting: %v", err) - ac.mu.Unlock() - grpclog.Warningf("grpc: addrConn.transportMonitor exits due to: %v", err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) + } else if ac.dopts.reqHandshake == envconfig.RequireHandshakeHybrid { + go func() { + select { + case <-prefaceTimer.C: + // We didn't get the preface in time. + newTr.Close() + case <-prefaceReceived: + // We got the preface just in the nick of time - huzzah! + case <-onCloseCalled: + // The transport has already closed - noop. } - return - } + }() } } -} -// wait blocks until i) the new transport is up or ii) ctx is done or iii) ac is closed or -// iv) transport is in connectivity.TransientFailure and there is a balancer/failfast is true. -func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (transport.ClientTransport, error) { - for { + if err != nil { + // newTr is either nil, or closed. + ac.cc.blockingpicker.updateConnectionError(err) ac.mu.Lock() - switch { - case ac.state == connectivity.Shutdown: - if failfast || !hasBalancer { - // RPC is failfast or balancer is nil. This RPC should fail with ac.tearDownErr. - err := ac.tearDownErr - ac.mu.Unlock() - return nil, err - } + if ac.state == connectivity.Shutdown { + // ac.tearDown(...) has been invoked. ac.mu.Unlock() + return nil, errConnClosing - case ac.state == connectivity.Ready: - ct := ac.transport - ac.mu.Unlock() - return ct, nil - case ac.state == connectivity.TransientFailure: - if failfast || hasBalancer { - ac.mu.Unlock() - return nil, errConnUnavailable + } + ac.mu.Unlock() + grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err) + return nil, err + } + + // Now there is a viable transport to be use, so set ac.transport to reflect the new viable transport. + ac.mu.Lock() + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + newTr.Close() + return nil, errConnClosing + } + ac.mu.Unlock() + + // Now there is a viable transport to be use, so set ac.transport to reflect the new viable transport. + ac.mu.Lock() + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + newTr.Close() + return nil, errConnClosing + } + ac.mu.Unlock() + + return newTr, nil +} + +func (ac *addrConn) startHealthCheck(ctx context.Context, newTr transport.ClientTransport, addr resolver.Address, serviceName string) { + // Set up the health check helper functions + newStream := func() (interface{}, error) { + return ac.newClientStream(ctx, &StreamDesc{ServerStreams: true}, "/grpc.health.v1.Health/Watch", newTr) + } + firstReady := true + reportHealth := func(ok bool) { + ac.mu.Lock() + defer ac.mu.Unlock() + if ac.transport != newTr { + return + } + if ok { + if firstReady { + firstReady = false + ac.curAddr = addr } + ac.updateConnectivityState(connectivity.Ready) + } else { + ac.updateConnectivityState(connectivity.TransientFailure) } - ready := ac.ready - if ready == nil { - ready = make(chan struct{}) - ac.ready = ready + } + err := ac.cc.dopts.healthCheckFunc(ctx, newStream, reportHealth, serviceName) + if err != nil { + if status.Code(err) == codes.Unimplemented { + if channelz.IsOn() { + channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{ + Desc: "Subchannel health check is unimplemented at server side, thus health check is disabled", + Severity: channelz.CtError, + }) + } + grpclog.Error("Subchannel health check is unimplemented at server side, thus health check is disabled") + } else { + grpclog.Errorf("HealthCheckFunc exits with unexpected error %v", err) } + } +} + +func (ac *addrConn) resetConnectBackoff() { + ac.mu.Lock() + close(ac.resetBackoff) + ac.backoffIdx = 0 + ac.resetBackoff = make(chan struct{}) + ac.mu.Unlock() +} + +// getReadyTransport returns the transport if ac's state is READY. +// Otherwise it returns nil, false. +// If ac's state is IDLE, it will trigger ac to connect. +func (ac *addrConn) getReadyTransport() (transport.ClientTransport, bool) { + ac.mu.Lock() + if ac.state == connectivity.Ready && ac.transport != nil { + t := ac.transport ac.mu.Unlock() - select { - case <-ctx.Done(): - return nil, toRPCErr(ctx.Err()) - // Wait until the new transport is ready or failed. - case <-ready: - } + return t, true } + var idle bool + if ac.state == connectivity.Idle { + idle = true + } + ac.mu.Unlock() + // Trigger idle ac to connect. + if idle { + ac.connect() + } + return nil, false } // tearDown starts to tear down the addrConn. @@ -1121,38 +1324,126 @@ func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (trans // tight loop. // tearDown doesn't remove ac from ac.cc.conns. func (ac *addrConn) tearDown(err error) { - ac.cancel() - ac.mu.Lock() - defer ac.mu.Unlock() - if ac.down != nil { - ac.down(downErrorf(false, false, "%v", err)) - ac.down = nil + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + return } - if err == errConnDrain && ac.transport != nil { + curTr := ac.transport + ac.transport = nil + // We have to set the state to Shutdown before anything else to prevent races + // between setting the state and logic that waits on context cancelation / etc. + ac.updateConnectivityState(connectivity.Shutdown) + ac.cancel() + ac.tearDownErr = err + ac.curAddr = resolver.Address{} + if err == errConnDrain && curTr != nil { // GracefulClose(...) may be executed multiple times when // i) receiving multiple GoAway frames from the server; or // ii) there are concurrent name resolver/Balancer triggered // address removal and GoAway. - ac.transport.GracefulClose() + // We have to unlock and re-lock here because GracefulClose => Close => onClose, which requires locking ac.mu. + ac.mu.Unlock() + curTr.GracefulClose() + ac.mu.Lock() } - if ac.state == connectivity.Shutdown { - return + if channelz.IsOn() { + channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{ + Desc: "Subchannel Deleted", + Severity: channelz.CtINFO, + Parent: &channelz.TraceEventDesc{ + Desc: fmt.Sprintf("Subchanel(id:%d) deleted", ac.channelzID), + Severity: channelz.CtINFO, + }, + }) + // TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to + // the entity beng deleted, and thus prevent it from being deleted right away. + channelz.RemoveEntry(ac.channelzID) } - oldState := ac.state - ac.state = connectivity.Shutdown - ac.tearDownErr = err - ac.csEvltr.recordTransition(oldState, ac.state) - if ac.events != nil { - ac.events.Finish() - ac.events = nil + ac.mu.Unlock() +} + +func (ac *addrConn) getState() connectivity.State { + ac.mu.Lock() + defer ac.mu.Unlock() + return ac.state +} + +func (ac *addrConn) ChannelzMetric() *channelz.ChannelInternalMetric { + ac.mu.Lock() + addr := ac.curAddr.Addr + ac.mu.Unlock() + return &channelz.ChannelInternalMetric{ + State: ac.getState(), + Target: addr, + CallsStarted: atomic.LoadInt64(&ac.czData.callsStarted), + CallsSucceeded: atomic.LoadInt64(&ac.czData.callsSucceeded), + CallsFailed: atomic.LoadInt64(&ac.czData.callsFailed), + LastCallStartedTimestamp: time.Unix(0, atomic.LoadInt64(&ac.czData.lastCallStartedTime)), } - if ac.ready != nil { - close(ac.ready) - ac.ready = nil +} + +func (ac *addrConn) incrCallsStarted() { + atomic.AddInt64(&ac.czData.callsStarted, 1) + atomic.StoreInt64(&ac.czData.lastCallStartedTime, time.Now().UnixNano()) +} + +func (ac *addrConn) incrCallsSucceeded() { + atomic.AddInt64(&ac.czData.callsSucceeded, 1) +} + +func (ac *addrConn) incrCallsFailed() { + atomic.AddInt64(&ac.czData.callsFailed, 1) +} + +type retryThrottler struct { + max float64 + thresh float64 + ratio float64 + + mu sync.Mutex + tokens float64 // TODO(dfawley): replace with atomic and remove lock. +} + +// throttle subtracts a retry token from the pool and returns whether a retry +// should be throttled (disallowed) based upon the retry throttling policy in +// the service config. +func (rt *retryThrottler) throttle() bool { + if rt == nil { + return false } - if ac.transport != nil && err != errConnDrain { - ac.transport.Close() + rt.mu.Lock() + defer rt.mu.Unlock() + rt.tokens-- + if rt.tokens < 0 { + rt.tokens = 0 } - return + return rt.tokens <= rt.thresh } + +func (rt *retryThrottler) successfulRPC() { + if rt == nil { + return + } + rt.mu.Lock() + defer rt.mu.Unlock() + rt.tokens += rt.ratio + if rt.tokens > rt.max { + rt.tokens = rt.max + } +} + +type channelzChannel struct { + cc *ClientConn +} + +func (c *channelzChannel) ChannelzMetric() *channelz.ChannelInternalMetric { + return c.cc.channelzMetric() +} + +// ErrClientConnTimeout indicates that the ClientConn cannot establish the +// underlying connections within the specified timeout. +// +// Deprecated: This error is never returned by grpc and should not be +// referenced by users. +var ErrClientConnTimeout = errors.New("grpc: timed out when dialing") -- cgit v1.2.3