mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-19 15:06:25 +01:00
1572 lines
48 KiB
Go
1572 lines
48 KiB
Go
/*
|
|
*
|
|
* Copyright 2014 gRPC authors.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
*/
|
|
|
|
package grpc
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"math"
|
|
"net"
|
|
"reflect"
|
|
"strings"
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"google.golang.org/grpc/balancer"
|
|
"google.golang.org/grpc/balancer/base"
|
|
"google.golang.org/grpc/codes"
|
|
"google.golang.org/grpc/connectivity"
|
|
"google.golang.org/grpc/credentials"
|
|
"google.golang.org/grpc/internal/backoff"
|
|
"google.golang.org/grpc/internal/channelz"
|
|
"google.golang.org/grpc/internal/grpcsync"
|
|
"google.golang.org/grpc/internal/grpcutil"
|
|
"google.golang.org/grpc/internal/transport"
|
|
"google.golang.org/grpc/keepalive"
|
|
"google.golang.org/grpc/resolver"
|
|
"google.golang.org/grpc/serviceconfig"
|
|
"google.golang.org/grpc/status"
|
|
|
|
_ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin.
|
|
_ "google.golang.org/grpc/internal/resolver/dns" // To register dns resolver.
|
|
_ "google.golang.org/grpc/internal/resolver/passthrough" // To register passthrough resolver.
|
|
)
|
|
|
|
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.
|
|
//
|
|
// 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")
|
|
// invalidDefaultServiceConfigErrPrefix is used to prefix the json parsing error for the default
|
|
// service config.
|
|
invalidDefaultServiceConfigErrPrefix = "grpc: the provided default service config is invalid"
|
|
)
|
|
|
|
// 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.
|
|
errTransportCredentialsMissing = errors.New("grpc: the credentials require transport level security (use grpc.WithTransportCredentials() to set)")
|
|
// 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)")
|
|
)
|
|
|
|
const (
|
|
defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4
|
|
defaultClientMaxSendMessageSize = math.MaxInt32
|
|
// http2IOBufSize specifies the buffer size for sending frames.
|
|
defaultWriteBufSize = 32 * 1024
|
|
defaultReadBufSize = 32 * 1024
|
|
)
|
|
|
|
// 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. 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[*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.apply(&cc.dopts)
|
|
}
|
|
|
|
chainUnaryClientInterceptors(cc)
|
|
chainStreamClientInterceptors(cc)
|
|
|
|
defer func() {
|
|
if err != nil {
|
|
cc.Close()
|
|
}
|
|
}()
|
|
|
|
if channelz.IsOn() {
|
|
if cc.dopts.channelzParentID != 0 {
|
|
cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target)
|
|
channelz.AddTraceEvent(logger, cc.channelzID, 0, &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.Info(logger, cc.channelzID, "Channel Created")
|
|
}
|
|
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
|
|
}
|
|
}
|
|
}
|
|
|
|
if cc.dopts.defaultServiceConfigRawJSON != nil {
|
|
scpr := parseServiceConfig(*cc.dopts.defaultServiceConfigRawJSON)
|
|
if scpr.Err != nil {
|
|
return nil, fmt.Errorf("%s: %v", invalidDefaultServiceConfigErrPrefix, scpr.Err)
|
|
}
|
|
cc.dopts.defaultServiceConfig, _ = scpr.Config.(*ServiceConfig)
|
|
}
|
|
cc.mkp = cc.dopts.copts.KeepaliveParams
|
|
|
|
if cc.dopts.copts.Dialer == nil {
|
|
cc.dopts.copts.Dialer = func(ctx context.Context, addr string) (net.Conn, error) {
|
|
network, addr := parseDialTarget(addr)
|
|
return (&net.Dialer{}).DialContext(ctx, network, addr)
|
|
}
|
|
if cc.dopts.withProxy {
|
|
cc.dopts.copts.Dialer = newProxyDialer(cc.dopts.copts.Dialer)
|
|
}
|
|
}
|
|
|
|
if cc.dopts.copts.UserAgent != "" {
|
|
cc.dopts.copts.UserAgent += " " + grpcUA
|
|
} else {
|
|
cc.dopts.copts.UserAgent = grpcUA
|
|
}
|
|
|
|
if cc.dopts.timeout > 0 {
|
|
var cancel context.CancelFunc
|
|
ctx, cancel = context.WithTimeout(ctx, cc.dopts.timeout)
|
|
defer cancel()
|
|
}
|
|
defer func() {
|
|
select {
|
|
case <-ctx.Done():
|
|
switch {
|
|
case ctx.Err() == err:
|
|
conn = nil
|
|
case err == nil || !cc.dopts.returnLastError:
|
|
conn, err = nil, ctx.Err()
|
|
default:
|
|
conn, err = nil, fmt.Errorf("%v: %v", ctx.Err(), err)
|
|
}
|
|
default:
|
|
}
|
|
}()
|
|
|
|
scSet := false
|
|
if cc.dopts.scChan != nil {
|
|
// Try to get an initial service config.
|
|
select {
|
|
case sc, ok := <-cc.dopts.scChan:
|
|
if ok {
|
|
cc.sc = &sc
|
|
scSet = true
|
|
}
|
|
default:
|
|
}
|
|
}
|
|
if cc.dopts.bs == nil {
|
|
cc.dopts.bs = backoff.DefaultExponential
|
|
}
|
|
|
|
// Determine the resolver to use.
|
|
cc.parsedTarget = grpcutil.ParseTarget(cc.target)
|
|
unixScheme := strings.HasPrefix(cc.target, "unix:")
|
|
channelz.Infof(logger, cc.channelzID, "parsed scheme: %q", cc.parsedTarget.Scheme)
|
|
resolverBuilder := cc.getResolver(cc.parsedTarget.Scheme)
|
|
if resolverBuilder == nil {
|
|
// If resolver builder is still nil, the parsed target's scheme is
|
|
// not registered. Fallback to default resolver and set Endpoint to
|
|
// the original target.
|
|
channelz.Infof(logger, cc.channelzID, "scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme)
|
|
cc.parsedTarget = resolver.Target{
|
|
Scheme: resolver.GetDefaultScheme(),
|
|
Endpoint: target,
|
|
}
|
|
resolverBuilder = cc.getResolver(cc.parsedTarget.Scheme)
|
|
if resolverBuilder == nil {
|
|
return nil, fmt.Errorf("could not get resolver for default scheme: %q", cc.parsedTarget.Scheme)
|
|
}
|
|
}
|
|
|
|
creds := cc.dopts.copts.TransportCredentials
|
|
if creds != nil && creds.Info().ServerName != "" {
|
|
cc.authority = creds.Info().ServerName
|
|
} else if cc.dopts.insecure && cc.dopts.authority != "" {
|
|
cc.authority = cc.dopts.authority
|
|
} else if unixScheme {
|
|
cc.authority = "localhost"
|
|
} else {
|
|
// 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 {
|
|
case sc, ok := <-cc.dopts.scChan:
|
|
if ok {
|
|
cc.sc = &sc
|
|
}
|
|
case <-ctx.Done():
|
|
return nil, ctx.Err()
|
|
}
|
|
}
|
|
if cc.dopts.scChan != nil {
|
|
go cc.scWatcher()
|
|
}
|
|
|
|
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,
|
|
Target: cc.parsedTarget,
|
|
}
|
|
|
|
// Build the resolver.
|
|
rWrapper, err := newCCResolverWrapper(cc, resolverBuilder)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to build resolver: %v", err)
|
|
}
|
|
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.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.
|
|
if err = cc.connectionError(); err != nil && cc.dopts.returnLastError {
|
|
return nil, err
|
|
}
|
|
return nil, ctx.Err()
|
|
}
|
|
}
|
|
}
|
|
|
|
return cc, nil
|
|
}
|
|
|
|
// chainUnaryClientInterceptors chains all unary client interceptors into one.
|
|
func chainUnaryClientInterceptors(cc *ClientConn) {
|
|
interceptors := cc.dopts.chainUnaryInts
|
|
// Prepend dopts.unaryInt to the chaining interceptors if it exists, since unaryInt will
|
|
// be executed before any other chained interceptors.
|
|
if cc.dopts.unaryInt != nil {
|
|
interceptors = append([]UnaryClientInterceptor{cc.dopts.unaryInt}, interceptors...)
|
|
}
|
|
var chainedInt UnaryClientInterceptor
|
|
if len(interceptors) == 0 {
|
|
chainedInt = nil
|
|
} else if len(interceptors) == 1 {
|
|
chainedInt = interceptors[0]
|
|
} else {
|
|
chainedInt = func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
|
|
return interceptors[0](ctx, method, req, reply, cc, getChainUnaryInvoker(interceptors, 0, invoker), opts...)
|
|
}
|
|
}
|
|
cc.dopts.unaryInt = chainedInt
|
|
}
|
|
|
|
// getChainUnaryInvoker recursively generate the chained unary invoker.
|
|
func getChainUnaryInvoker(interceptors []UnaryClientInterceptor, curr int, finalInvoker UnaryInvoker) UnaryInvoker {
|
|
if curr == len(interceptors)-1 {
|
|
return finalInvoker
|
|
}
|
|
return func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error {
|
|
return interceptors[curr+1](ctx, method, req, reply, cc, getChainUnaryInvoker(interceptors, curr+1, finalInvoker), opts...)
|
|
}
|
|
}
|
|
|
|
// chainStreamClientInterceptors chains all stream client interceptors into one.
|
|
func chainStreamClientInterceptors(cc *ClientConn) {
|
|
interceptors := cc.dopts.chainStreamInts
|
|
// Prepend dopts.streamInt to the chaining interceptors if it exists, since streamInt will
|
|
// be executed before any other chained interceptors.
|
|
if cc.dopts.streamInt != nil {
|
|
interceptors = append([]StreamClientInterceptor{cc.dopts.streamInt}, interceptors...)
|
|
}
|
|
var chainedInt StreamClientInterceptor
|
|
if len(interceptors) == 0 {
|
|
chainedInt = nil
|
|
} else if len(interceptors) == 1 {
|
|
chainedInt = interceptors[0]
|
|
} else {
|
|
chainedInt = func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error) {
|
|
return interceptors[0](ctx, desc, cc, method, getChainStreamer(interceptors, 0, streamer), opts...)
|
|
}
|
|
}
|
|
cc.dopts.streamInt = chainedInt
|
|
}
|
|
|
|
// getChainStreamer recursively generate the chained client stream constructor.
|
|
func getChainStreamer(interceptors []StreamClientInterceptor, curr int, finalStreamer Streamer) Streamer {
|
|
if curr == len(interceptors)-1 {
|
|
return finalStreamer
|
|
}
|
|
return func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
|
|
return interceptors[curr+1](ctx, desc, cc, method, getChainStreamer(interceptors, curr+1, finalStreamer), opts...)
|
|
}
|
|
}
|
|
|
|
// connectivityStateManager keeps the connectivity.State of ClientConn.
|
|
// This struct will eventually be exported so the balancers can access it.
|
|
type connectivityStateManager struct {
|
|
mu sync.Mutex
|
|
state connectivity.State
|
|
notifyChan chan struct{}
|
|
channelzID int64
|
|
}
|
|
|
|
// updateState updates the connectivity.State of ClientConn.
|
|
// If there's a change it notifies goroutines waiting on state change to
|
|
// happen.
|
|
func (csm *connectivityStateManager) updateState(state connectivity.State) {
|
|
csm.mu.Lock()
|
|
defer csm.mu.Unlock()
|
|
if csm.state == connectivity.Shutdown {
|
|
return
|
|
}
|
|
if csm.state == state {
|
|
return
|
|
}
|
|
csm.state = state
|
|
channelz.Infof(logger, csm.channelzID, "Channel Connectivity change to %v", state)
|
|
if csm.notifyChan != nil {
|
|
// There are other goroutines waiting on this channel.
|
|
close(csm.notifyChan)
|
|
csm.notifyChan = nil
|
|
}
|
|
}
|
|
|
|
func (csm *connectivityStateManager) getState() connectivity.State {
|
|
csm.mu.Lock()
|
|
defer csm.mu.Unlock()
|
|
return csm.state
|
|
}
|
|
|
|
func (csm *connectivityStateManager) getNotifyChan() <-chan struct{} {
|
|
csm.mu.Lock()
|
|
defer csm.mu.Unlock()
|
|
if csm.notifyChan == nil {
|
|
csm.notifyChan = make(chan struct{})
|
|
}
|
|
return csm.notifyChan
|
|
}
|
|
|
|
// ClientConnInterface defines the functions clients need to perform unary and
|
|
// streaming RPCs. It is implemented by *ClientConn, and is only intended to
|
|
// be referenced by generated code.
|
|
type ClientConnInterface interface {
|
|
// Invoke performs a unary RPC and returns after the response is received
|
|
// into reply.
|
|
Invoke(ctx context.Context, method string, args interface{}, reply interface{}, opts ...CallOption) error
|
|
// NewStream begins a streaming RPC.
|
|
NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
|
|
}
|
|
|
|
// Assert *ClientConn implements ClientConnInterface.
|
|
var _ ClientConnInterface = (*ClientConn)(nil)
|
|
|
|
// ClientConn represents a virtual connection to a conceptual endpoint, to
|
|
// perform RPCs.
|
|
//
|
|
// A ClientConn is free to have zero or more actual connections to the endpoint
|
|
// based on configuration, load, etc. It is also free to determine which actual
|
|
// endpoints to use and may change it every RPC, permitting client-side load
|
|
// balancing.
|
|
//
|
|
// A ClientConn encapsulates a range of functionality including name
|
|
// resolution, TCP connection establishment (with retries and backoff) and TLS
|
|
// handshakes. It also handles errors on established connections by
|
|
// re-resolving the name and reconnecting.
|
|
type ClientConn struct {
|
|
ctx context.Context
|
|
cancel context.CancelFunc
|
|
|
|
target string
|
|
parsedTarget resolver.Target
|
|
authority string
|
|
dopts dialOptions
|
|
csMgr *connectivityStateManager
|
|
|
|
balancerBuildOpts balancer.BuildOptions
|
|
blockingpicker *pickerWrapper
|
|
|
|
mu sync.RWMutex
|
|
resolverWrapper *ccResolverWrapper
|
|
sc *ServiceConfig
|
|
conns map[*addrConn]struct{}
|
|
// Keepalive parameter can be updated if a GoAway is received.
|
|
mkp keepalive.ClientParameters
|
|
curBalancerName string
|
|
balancerWrapper *ccBalancerWrapper
|
|
retryThrottler atomic.Value
|
|
|
|
firstResolveEvent *grpcsync.Event
|
|
|
|
channelzID int64 // channelz unique identification number
|
|
czData *channelzData
|
|
|
|
lceMu sync.Mutex // protects lastConnectionError
|
|
lastConnectionError error
|
|
}
|
|
|
|
// WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or
|
|
// ctx expires. A true value is returned in former case and false in latter.
|
|
//
|
|
// Experimental
|
|
//
|
|
// Notice: This API is EXPERIMENTAL and may be changed or removed in a
|
|
// later release.
|
|
func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool {
|
|
ch := cc.csMgr.getNotifyChan()
|
|
if cc.csMgr.getState() != sourceState {
|
|
return true
|
|
}
|
|
select {
|
|
case <-ctx.Done():
|
|
return false
|
|
case <-ch:
|
|
return true
|
|
}
|
|
}
|
|
|
|
// GetState returns the connectivity.State of ClientConn.
|
|
//
|
|
// Experimental
|
|
//
|
|
// Notice: This API is EXPERIMENTAL and may be changed or removed in a
|
|
// later release.
|
|
func (cc *ClientConn) GetState() connectivity.State {
|
|
return cc.csMgr.getState()
|
|
}
|
|
|
|
func (cc *ClientConn) scWatcher() {
|
|
for {
|
|
select {
|
|
case sc, ok := <-cc.dopts.scChan:
|
|
if !ok {
|
|
return
|
|
}
|
|
cc.mu.Lock()
|
|
// TODO: load balance policy runtime change is ignored.
|
|
// We may revisit this decision in the future.
|
|
cc.sc = &sc
|
|
cc.mu.Unlock()
|
|
case <-cc.ctx.Done():
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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
|
|
}
|
|
select {
|
|
case <-cc.firstResolveEvent.Done():
|
|
return nil
|
|
case <-ctx.Done():
|
|
return status.FromContextError(ctx.Err()).Err()
|
|
case <-cc.ctx.Done():
|
|
return ErrClientConnClosing
|
|
}
|
|
}
|
|
|
|
var emptyServiceConfig *ServiceConfig
|
|
|
|
func init() {
|
|
cfg := parseServiceConfig("{}")
|
|
if cfg.Err != nil {
|
|
panic(fmt.Sprintf("impossible error parsing empty service config: %v", cfg.Err))
|
|
}
|
|
emptyServiceConfig = cfg.Config.(*ServiceConfig)
|
|
}
|
|
|
|
func (cc *ClientConn) maybeApplyDefaultServiceConfig(addrs []resolver.Address) {
|
|
if cc.sc != nil {
|
|
cc.applyServiceConfigAndBalancer(cc.sc, addrs)
|
|
return
|
|
}
|
|
if cc.dopts.defaultServiceConfig != nil {
|
|
cc.applyServiceConfigAndBalancer(cc.dopts.defaultServiceConfig, addrs)
|
|
} else {
|
|
cc.applyServiceConfigAndBalancer(emptyServiceConfig, addrs)
|
|
}
|
|
}
|
|
|
|
func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
|
|
defer cc.firstResolveEvent.Fire()
|
|
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
|
|
}
|
|
|
|
if err != nil {
|
|
// May need to apply the initial service config in case the resolver
|
|
// doesn't support service configs, or doesn't provide a service config
|
|
// with the new addresses.
|
|
cc.maybeApplyDefaultServiceConfig(nil)
|
|
|
|
if cc.balancerWrapper != nil {
|
|
cc.balancerWrapper.resolverError(err)
|
|
}
|
|
|
|
// No addresses are valid with err set; return early.
|
|
cc.mu.Unlock()
|
|
return balancer.ErrBadResolverState
|
|
}
|
|
|
|
var ret error
|
|
if cc.dopts.disableServiceConfig || s.ServiceConfig == nil {
|
|
cc.maybeApplyDefaultServiceConfig(s.Addresses)
|
|
// TODO: do we need to apply a failing LB policy if there is no
|
|
// default, per the error handling design?
|
|
} else {
|
|
if sc, ok := s.ServiceConfig.Config.(*ServiceConfig); s.ServiceConfig.Err == nil && ok {
|
|
cc.applyServiceConfigAndBalancer(sc, s.Addresses)
|
|
} else {
|
|
ret = balancer.ErrBadResolverState
|
|
if cc.balancerWrapper == nil {
|
|
var err error
|
|
if s.ServiceConfig.Err != nil {
|
|
err = status.Errorf(codes.Unavailable, "error parsing service config: %v", s.ServiceConfig.Err)
|
|
} else {
|
|
err = status.Errorf(codes.Unavailable, "illegal service config type: %T", s.ServiceConfig.Config)
|
|
}
|
|
cc.blockingpicker.updatePicker(base.NewErrPicker(err))
|
|
cc.csMgr.updateState(connectivity.TransientFailure)
|
|
cc.mu.Unlock()
|
|
return ret
|
|
}
|
|
}
|
|
}
|
|
|
|
var balCfg serviceconfig.LoadBalancingConfig
|
|
if cc.dopts.balancerBuilder == nil && cc.sc != nil && cc.sc.lbConfig != nil {
|
|
balCfg = cc.sc.lbConfig.cfg
|
|
}
|
|
|
|
cbn := cc.curBalancerName
|
|
bw := cc.balancerWrapper
|
|
cc.mu.Unlock()
|
|
if cbn != grpclbName {
|
|
// Filter any grpclb addresses since we don't have the grpclb balancer.
|
|
for i := 0; i < len(s.Addresses); {
|
|
if s.Addresses[i].Type == resolver.GRPCLB {
|
|
copy(s.Addresses[i:], s.Addresses[i+1:])
|
|
s.Addresses = s.Addresses[:len(s.Addresses)-1]
|
|
continue
|
|
}
|
|
i++
|
|
}
|
|
}
|
|
uccsErr := bw.updateClientConnState(&balancer.ClientConnState{ResolverState: s, BalancerConfig: balCfg})
|
|
if ret == nil {
|
|
ret = uccsErr // prefer ErrBadResolver state since any other error is
|
|
// currently meaningless to the caller.
|
|
}
|
|
return ret
|
|
}
|
|
|
|
// 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 strings.EqualFold(cc.curBalancerName, name) {
|
|
return
|
|
}
|
|
|
|
channelz.Infof(logger, cc.channelzID, "ClientConn switching balancer to %q", name)
|
|
if cc.dopts.balancerBuilder != nil {
|
|
channelz.Info(logger, cc.channelzID, "ignoring balancer switching: Balancer DialOption used instead")
|
|
return
|
|
}
|
|
if cc.balancerWrapper != nil {
|
|
cc.balancerWrapper.close()
|
|
}
|
|
|
|
builder := balancer.Get(name)
|
|
if builder == nil {
|
|
channelz.Warningf(logger, cc.channelzID, "Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName)
|
|
channelz.Infof(logger, cc.channelzID, "failed to get balancer builder for: %v, using pick_first instead", name)
|
|
builder = newPickfirstBuilder()
|
|
} else {
|
|
channelz.Infof(logger, cc.channelzID, "Channel switches to new LB policy %q", name)
|
|
}
|
|
|
|
cc.curBalancerName = builder.Name()
|
|
cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts)
|
|
}
|
|
|
|
func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
|
|
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, err)
|
|
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{
|
|
state: connectivity.Idle,
|
|
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(logger, ac.channelzID, 0, &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.
|
|
//
|
|
// Experimental
|
|
//
|
|
// Notice: This API is EXPERIMENTAL and may be changed or removed in a
|
|
// later release.
|
|
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
|
|
}
|
|
// Update connectivity state within the lock to prevent subsequent or
|
|
// concurrent calls from resetting the transport more than once.
|
|
ac.updateConnectivityState(connectivity.Connecting, nil)
|
|
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.
|
|
//
|
|
// If ac is Connecting, it returns false. The caller should tear down the ac and
|
|
// create a new one. Note that the backoff will be reset when this happens.
|
|
//
|
|
// If ac is TransientFailure, it updates ac.addrs and returns true. The updated
|
|
// addresses will be picked up by retry in the next iteration after backoff.
|
|
//
|
|
// If ac is Shutdown or Idle, it updates ac.addrs and returns true.
|
|
//
|
|
// If ac is Ready, 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()
|
|
channelz.Infof(logger, ac.channelzID, "addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs)
|
|
if ac.state == connectivity.Shutdown ||
|
|
ac.state == connectivity.TransientFailure ||
|
|
ac.state == connectivity.Idle {
|
|
ac.addrs = addrs
|
|
return true
|
|
}
|
|
|
|
if ac.state == connectivity.Connecting {
|
|
return false
|
|
}
|
|
|
|
// ac.state is Ready, try to find the connected address.
|
|
var curAddrFound bool
|
|
for _, a := range addrs {
|
|
if reflect.DeepEqual(ac.curAddr, a) {
|
|
curAddrFound = true
|
|
break
|
|
}
|
|
}
|
|
channelz.Infof(logger, ac.channelzID, "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 service's default
|
|
// config under the service (i.e /service/) and then for the default for all services (empty string).
|
|
//
|
|
// 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()
|
|
if cc.sc == nil {
|
|
return MethodConfig{}
|
|
}
|
|
if m, ok := cc.sc.Methods[method]; ok {
|
|
return m
|
|
}
|
|
i := strings.LastIndex(method, "/")
|
|
if m, ok := cc.sc.Methods[method[:i+1]]; ok {
|
|
return m
|
|
}
|
|
return cc.sc.Methods[""]
|
|
}
|
|
|
|
func (cc *ClientConn) healthCheckConfig() *healthCheckConfig {
|
|
cc.mu.RLock()
|
|
defer cc.mu.RUnlock()
|
|
if cc.sc == nil {
|
|
return nil
|
|
}
|
|
return cc.sc.healthCheckConfig
|
|
}
|
|
|
|
func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) {
|
|
t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickInfo{
|
|
Ctx: ctx,
|
|
FullMethodName: method,
|
|
})
|
|
if err != nil {
|
|
return nil, nil, toRPCErr(err)
|
|
}
|
|
return t, done, nil
|
|
}
|
|
|
|
func (cc *ClientConn) applyServiceConfigAndBalancer(sc *ServiceConfig, addrs []resolver.Address) {
|
|
if sc == nil {
|
|
// should never reach here.
|
|
return
|
|
}
|
|
cc.sc = sc
|
|
|
|
if cc.sc.retryThrottling != nil {
|
|
newThrottler := &retryThrottler{
|
|
tokens: cc.sc.retryThrottling.MaxTokens,
|
|
max: cc.sc.retryThrottling.MaxTokens,
|
|
thresh: cc.sc.retryThrottling.MaxTokens / 2,
|
|
ratio: cc.sc.retryThrottling.TokenRatio,
|
|
}
|
|
cc.retryThrottler.Store(newThrottler)
|
|
} else {
|
|
cc.retryThrottler.Store((*retryThrottler)(nil))
|
|
}
|
|
|
|
if cc.dopts.balancerBuilder == nil {
|
|
// Only look at balancer types and switch balancer if balancer dial
|
|
// option is not set.
|
|
var newBalancerName string
|
|
if cc.sc != nil && cc.sc.lbConfig != nil {
|
|
newBalancerName = cc.sc.lbConfig.name
|
|
} else {
|
|
var isGRPCLB bool
|
|
for _, a := range addrs {
|
|
if a.Type == resolver.GRPCLB {
|
|
isGRPCLB = true
|
|
break
|
|
}
|
|
}
|
|
if isGRPCLB {
|
|
newBalancerName = grpclbName
|
|
} else if cc.sc != nil && cc.sc.LB != nil {
|
|
newBalancerName = *cc.sc.LB
|
|
} else {
|
|
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.curBalancerName = cc.dopts.balancerBuilder.Name()
|
|
cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts)
|
|
}
|
|
}
|
|
|
|
func (cc *ClientConn) resolveNow(o resolver.ResolveNowOptions) {
|
|
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.
|
|
//
|
|
// Experimental
|
|
//
|
|
// Notice: This API is EXPERIMENTAL and may be changed or removed in a
|
|
// later release.
|
|
func (cc *ClientConn) ResetConnectBackoff() {
|
|
cc.mu.Lock()
|
|
conns := cc.conns
|
|
cc.mu.Unlock()
|
|
for ac := range conns {
|
|
ac.resetConnectBackoff()
|
|
}
|
|
}
|
|
|
|
// Close tears down the ClientConn and all underlying connections.
|
|
func (cc *ClientConn) Close() error {
|
|
defer cc.cancel()
|
|
|
|
cc.mu.Lock()
|
|
if cc.conns == nil {
|
|
cc.mu.Unlock()
|
|
return ErrClientConnClosing
|
|
}
|
|
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()
|
|
|
|
cc.blockingpicker.close()
|
|
|
|
if rWrapper != nil {
|
|
rWrapper.close()
|
|
}
|
|
if bWrapper != nil {
|
|
bWrapper.close()
|
|
}
|
|
|
|
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(logger, cc.channelzID, 0, ted)
|
|
// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
|
|
// the entity being deleted, and thus prevent it from being deleted right away.
|
|
channelz.RemoveEntry(cc.channelzID)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// addrConn is a network connection to a given address.
|
|
type addrConn struct {
|
|
ctx context.Context
|
|
cancel context.CancelFunc
|
|
|
|
cc *ClientConn
|
|
dopts dialOptions
|
|
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.
|
|
|
|
mu sync.Mutex
|
|
curAddr resolver.Address // The current address.
|
|
addrs []resolver.Address // All addresses that the resolver resolved to.
|
|
|
|
// Use updateConnectivityState for updating addrConn's connectivity state.
|
|
state connectivity.State
|
|
|
|
backoffIdx int // Needs to be stateful for resetConnectBackoff.
|
|
resetBackoff chan struct{}
|
|
|
|
channelzID int64 // channelz unique identification number.
|
|
czData *channelzData
|
|
}
|
|
|
|
// Note: this requires a lock on ac.mu.
|
|
func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error) {
|
|
if ac.state == s {
|
|
return
|
|
}
|
|
ac.state = s
|
|
channelz.Infof(logger, ac.channelzID, "Subchannel Connectivity change to %v", s)
|
|
ac.cc.handleSubConnStateChange(ac.acbw, s, lastErr)
|
|
}
|
|
|
|
// adjustParams updates parameters used to create transports upon
|
|
// receiving a GoAway.
|
|
func (ac *addrConn) adjustParams(r transport.GoAwayReason) {
|
|
switch r {
|
|
case transport.GoAwayTooManyPings:
|
|
v := 2 * ac.dopts.copts.KeepaliveParams.Time
|
|
ac.cc.mu.Lock()
|
|
if v > ac.cc.mkp.Time {
|
|
ac.cc.mkp.Time = v
|
|
}
|
|
ac.cc.mu.Unlock()
|
|
}
|
|
}
|
|
|
|
func (ac *addrConn) resetTransport() {
|
|
for i := 0; ; i++ {
|
|
if i > 0 {
|
|
ac.cc.resolveNow(resolver.ResolveNowOptions{})
|
|
}
|
|
|
|
ac.mu.Lock()
|
|
if ac.state == connectivity.Shutdown {
|
|
ac.mu.Unlock()
|
|
return
|
|
}
|
|
|
|
addrs := ac.addrs
|
|
backoffFor := ac.dopts.bs.Backoff(ac.backoffIdx)
|
|
// This will be the duration that dial gets to finish.
|
|
dialDuration := minConnectTimeout
|
|
if ac.dopts.minConnectTimeout != nil {
|
|
dialDuration = ac.dopts.minConnectTimeout()
|
|
}
|
|
|
|
if dialDuration < backoffFor {
|
|
// Give dial more time as we keep failing to connect.
|
|
dialDuration = backoffFor
|
|
}
|
|
// We can potentially spend all the time trying the first address, and
|
|
// if the server accepts the connection and then hangs, the following
|
|
// addresses will never be tried.
|
|
//
|
|
// The spec doesn't mention what should be done for multiple addresses.
|
|
// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md#proposed-backoff-algorithm
|
|
connectDeadline := time.Now().Add(dialDuration)
|
|
|
|
ac.updateConnectivityState(connectivity.Connecting, nil)
|
|
ac.transport = nil
|
|
ac.mu.Unlock()
|
|
|
|
newTr, addr, reconnect, err := ac.tryAllAddrs(addrs, connectDeadline)
|
|
if err != nil {
|
|
// After exhausting all addresses, the addrConn enters
|
|
// TRANSIENT_FAILURE.
|
|
ac.mu.Lock()
|
|
if ac.state == connectivity.Shutdown {
|
|
ac.mu.Unlock()
|
|
return
|
|
}
|
|
ac.updateConnectivityState(connectivity.TransientFailure, err)
|
|
|
|
// Backoff.
|
|
b := ac.resetBackoff
|
|
ac.mu.Unlock()
|
|
|
|
timer := time.NewTimer(backoffFor)
|
|
select {
|
|
case <-timer.C:
|
|
ac.mu.Lock()
|
|
ac.backoffIdx++
|
|
ac.mu.Unlock()
|
|
case <-b:
|
|
timer.Stop()
|
|
case <-ac.ctx.Done():
|
|
timer.Stop()
|
|
return
|
|
}
|
|
continue
|
|
}
|
|
|
|
ac.mu.Lock()
|
|
if ac.state == connectivity.Shutdown {
|
|
ac.mu.Unlock()
|
|
newTr.Close()
|
|
return
|
|
}
|
|
ac.curAddr = addr
|
|
ac.transport = newTr
|
|
ac.backoffIdx = 0
|
|
|
|
hctx, hcancel := context.WithCancel(ac.ctx)
|
|
ac.startHealthCheck(hctx)
|
|
ac.mu.Unlock()
|
|
|
|
// Block until the created transport is down. And when this happens,
|
|
// we restart from the top of the addr list.
|
|
<-reconnect.Done()
|
|
hcancel()
|
|
// restart connecting - the top of the loop will set state to
|
|
// CONNECTING. This is against the current connectivity semantics doc,
|
|
// however it allows for graceful behavior for RPCs not yet dispatched
|
|
// - unfortunate timing would otherwise lead to the RPC failing even
|
|
// though the TRANSIENT_FAILURE state (called for by the doc) would be
|
|
// instantaneous.
|
|
//
|
|
// Ideally we should transition to Idle here and block until there is
|
|
// RPC activity that leads to the balancer requesting a reconnect of
|
|
// the associated SubConn.
|
|
}
|
|
}
|
|
|
|
// tryAllAddrs tries to creates a connection to the addresses, and stop when at the
|
|
// first successful one. It returns the transport, the address and a Event in
|
|
// the successful case. The Event fires when the returned transport disconnects.
|
|
func (ac *addrConn) tryAllAddrs(addrs []resolver.Address, connectDeadline time.Time) (transport.ClientTransport, resolver.Address, *grpcsync.Event, error) {
|
|
var firstConnErr error
|
|
for _, addr := range addrs {
|
|
ac.mu.Lock()
|
|
if ac.state == connectivity.Shutdown {
|
|
ac.mu.Unlock()
|
|
return nil, resolver.Address{}, nil, errConnClosing
|
|
}
|
|
|
|
ac.cc.mu.RLock()
|
|
ac.dopts.copts.KeepaliveParams = ac.cc.mkp
|
|
ac.cc.mu.RUnlock()
|
|
|
|
copts := ac.dopts.copts
|
|
if ac.scopts.CredsBundle != nil {
|
|
copts.CredsBundle = ac.scopts.CredsBundle
|
|
}
|
|
ac.mu.Unlock()
|
|
|
|
channelz.Infof(logger, ac.channelzID, "Subchannel picks a new address %q to connect", addr.Addr)
|
|
|
|
newTr, reconnect, err := ac.createTransport(addr, copts, connectDeadline)
|
|
if err == nil {
|
|
return newTr, addr, reconnect, nil
|
|
}
|
|
if firstConnErr == nil {
|
|
firstConnErr = err
|
|
}
|
|
ac.cc.updateConnectionError(err)
|
|
}
|
|
|
|
// Couldn't connect to any address.
|
|
return nil, resolver.Address{}, nil, firstConnErr
|
|
}
|
|
|
|
// createTransport creates a connection to addr. It returns the transport and a
|
|
// Event in the successful case. The Event fires when the returned transport
|
|
// disconnects.
|
|
func (ac *addrConn) createTransport(addr resolver.Address, copts transport.ConnectOptions, connectDeadline time.Time) (transport.ClientTransport, *grpcsync.Event, error) {
|
|
prefaceReceived := make(chan struct{})
|
|
onCloseCalled := make(chan struct{})
|
|
reconnect := grpcsync.NewEvent()
|
|
|
|
// addr.ServerName takes precedent over ClientConn authority, if present.
|
|
if addr.ServerName == "" {
|
|
addr.ServerName = ac.cc.authority
|
|
}
|
|
|
|
once := sync.Once{}
|
|
onGoAway := func(r transport.GoAwayReason) {
|
|
ac.mu.Lock()
|
|
ac.adjustParams(r)
|
|
once.Do(func() {
|
|
if ac.state == connectivity.Ready {
|
|
// Prevent this SubConn from being used for new RPCs by setting its
|
|
// state to Connecting.
|
|
//
|
|
// TODO: this should be Idle when grpc-go properly supports it.
|
|
ac.updateConnectivityState(connectivity.Connecting, nil)
|
|
}
|
|
})
|
|
ac.mu.Unlock()
|
|
reconnect.Fire()
|
|
}
|
|
|
|
onClose := func() {
|
|
ac.mu.Lock()
|
|
once.Do(func() {
|
|
if ac.state == connectivity.Ready {
|
|
// Prevent this SubConn from being used for new RPCs by setting its
|
|
// state to Connecting.
|
|
//
|
|
// TODO: this should be Idle when grpc-go properly supports it.
|
|
ac.updateConnectivityState(connectivity.Connecting, nil)
|
|
}
|
|
})
|
|
ac.mu.Unlock()
|
|
close(onCloseCalled)
|
|
reconnect.Fire()
|
|
}
|
|
|
|
onPrefaceReceipt := func() {
|
|
close(prefaceReceived)
|
|
}
|
|
|
|
connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline)
|
|
defer cancel()
|
|
if channelz.IsOn() {
|
|
copts.ChannelzParentID = ac.channelzID
|
|
}
|
|
|
|
newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, addr, copts, onPrefaceReceipt, onGoAway, onClose)
|
|
if err != nil {
|
|
// newTr is either nil, or closed.
|
|
channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v. Err: %v. Reconnecting...", addr, err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
select {
|
|
case <-time.After(time.Until(connectDeadline)):
|
|
// We didn't get the preface in time.
|
|
newTr.Close()
|
|
channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v: didn't receive server preface in time. Reconnecting...", addr)
|
|
return nil, nil, 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, nil, errors.New("connection closed")
|
|
// TODO(deklerk) this should bail on ac.ctx.Done(). Add a test and fix.
|
|
}
|
|
return newTr, reconnect, nil
|
|
}
|
|
|
|
// startHealthCheck starts the health checking stream (RPC) to watch the health
|
|
// stats of this connection if health checking is requested and configured.
|
|
//
|
|
// LB channel health checking is enabled when all requirements below are met:
|
|
// 1. it is not disabled by the user with the WithDisableHealthCheck DialOption
|
|
// 2. internal.HealthCheckFunc is set by importing the grpc/health package
|
|
// 3. a service config with non-empty healthCheckConfig field is provided
|
|
// 4. the load balancer requests it
|
|
//
|
|
// It sets addrConn to READY if the health checking stream is not started.
|
|
//
|
|
// Caller must hold ac.mu.
|
|
func (ac *addrConn) startHealthCheck(ctx context.Context) {
|
|
var healthcheckManagingState bool
|
|
defer func() {
|
|
if !healthcheckManagingState {
|
|
ac.updateConnectivityState(connectivity.Ready, nil)
|
|
}
|
|
}()
|
|
|
|
if ac.cc.dopts.disableHealthCheck {
|
|
return
|
|
}
|
|
healthCheckConfig := ac.cc.healthCheckConfig()
|
|
if healthCheckConfig == nil {
|
|
return
|
|
}
|
|
if !ac.scopts.HealthCheckEnabled {
|
|
return
|
|
}
|
|
healthCheckFunc := ac.cc.dopts.healthCheckFunc
|
|
if healthCheckFunc == nil {
|
|
// The health package is not imported to set health check function.
|
|
//
|
|
// TODO: add a link to the health check doc in the error message.
|
|
channelz.Error(logger, ac.channelzID, "Health check is requested but health check function is not set.")
|
|
return
|
|
}
|
|
|
|
healthcheckManagingState = true
|
|
|
|
// Set up the health check helper functions.
|
|
currentTr := ac.transport
|
|
newStream := func(method string) (interface{}, error) {
|
|
ac.mu.Lock()
|
|
if ac.transport != currentTr {
|
|
ac.mu.Unlock()
|
|
return nil, status.Error(codes.Canceled, "the provided transport is no longer valid to use")
|
|
}
|
|
ac.mu.Unlock()
|
|
return newNonRetryClientStream(ctx, &StreamDesc{ServerStreams: true}, method, currentTr, ac)
|
|
}
|
|
setConnectivityState := func(s connectivity.State, lastErr error) {
|
|
ac.mu.Lock()
|
|
defer ac.mu.Unlock()
|
|
if ac.transport != currentTr {
|
|
return
|
|
}
|
|
ac.updateConnectivityState(s, lastErr)
|
|
}
|
|
// Start the health checking stream.
|
|
go func() {
|
|
err := ac.cc.dopts.healthCheckFunc(ctx, newStream, setConnectivityState, healthCheckConfig.ServiceName)
|
|
if err != nil {
|
|
if status.Code(err) == codes.Unimplemented {
|
|
channelz.Error(logger, ac.channelzID, "Subchannel health check is unimplemented at server side, thus health check is disabled")
|
|
} else {
|
|
channelz.Errorf(logger, ac.channelzID, "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()
|
|
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.
|
|
// TODO(zhaoq): Make this synchronous to avoid unbounded memory consumption in
|
|
// some edge cases (e.g., the caller opens and closes many addrConn's in a
|
|
// tight loop.
|
|
// tearDown doesn't remove ac from ac.cc.conns.
|
|
func (ac *addrConn) tearDown(err error) {
|
|
ac.mu.Lock()
|
|
if ac.state == connectivity.Shutdown {
|
|
ac.mu.Unlock()
|
|
return
|
|
}
|
|
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 cancellation / etc.
|
|
ac.updateConnectivityState(connectivity.Shutdown, nil)
|
|
ac.cancel()
|
|
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.
|
|
// 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 channelz.IsOn() {
|
|
channelz.AddTraceEvent(logger, ac.channelzID, 0, &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 being deleted, and thus prevent it from being deleted right away.
|
|
channelz.RemoveEntry(ac.channelzID)
|
|
}
|
|
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)),
|
|
}
|
|
}
|
|
|
|
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
|
|
}
|
|
rt.mu.Lock()
|
|
defer rt.mu.Unlock()
|
|
rt.tokens--
|
|
if rt.tokens < 0 {
|
|
rt.tokens = 0
|
|
}
|
|
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")
|
|
|
|
func (cc *ClientConn) getResolver(scheme string) resolver.Builder {
|
|
for _, rb := range cc.dopts.resolvers {
|
|
if scheme == rb.Scheme() {
|
|
return rb
|
|
}
|
|
}
|
|
return resolver.Get(scheme)
|
|
}
|
|
|
|
func (cc *ClientConn) updateConnectionError(err error) {
|
|
cc.lceMu.Lock()
|
|
cc.lastConnectionError = err
|
|
cc.lceMu.Unlock()
|
|
}
|
|
|
|
func (cc *ClientConn) connectionError() error {
|
|
cc.lceMu.Lock()
|
|
defer cc.lceMu.Unlock()
|
|
return cc.lastConnectionError
|
|
}
|