From 1e5c432e1029601a664454388ae366ef69618d62 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Mon, 25 Jun 2018 12:33:13 -0700 Subject: MM-10702 Moving plugins to use hashicorp go-plugin. (#8978) * Moving plugins to use hashicorp go-plugin. * Tweaks from feedback. --- vendor/google.golang.org/grpc/grpclb.go | 341 ++++++++++++++++++++++++++++++++ 1 file changed, 341 insertions(+) create mode 100644 vendor/google.golang.org/grpc/grpclb.go (limited to 'vendor/google.golang.org/grpc/grpclb.go') diff --git a/vendor/google.golang.org/grpc/grpclb.go b/vendor/google.golang.org/grpc/grpclb.go new file mode 100644 index 000000000..bc2b44525 --- /dev/null +++ b/vendor/google.golang.org/grpc/grpclb.go @@ -0,0 +1,341 @@ +/* + * + * Copyright 2016 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 ( + "strconv" + "strings" + "sync" + "time" + + "golang.org/x/net/context" + "google.golang.org/grpc/balancer" + "google.golang.org/grpc/connectivity" + lbpb "google.golang.org/grpc/grpclb/grpc_lb_v1/messages" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/resolver" +) + +const ( + lbTokeyKey = "lb-token" + defaultFallbackTimeout = 10 * time.Second + grpclbName = "grpclb" +) + +func convertDuration(d *lbpb.Duration) time.Duration { + if d == nil { + return 0 + } + return time.Duration(d.Seconds)*time.Second + time.Duration(d.Nanos)*time.Nanosecond +} + +// Client API for LoadBalancer service. +// Mostly copied from generated pb.go file. +// To avoid circular dependency. +type loadBalancerClient struct { + cc *ClientConn +} + +func (c *loadBalancerClient) BalanceLoad(ctx context.Context, opts ...CallOption) (*balanceLoadClientStream, error) { + desc := &StreamDesc{ + StreamName: "BalanceLoad", + ServerStreams: true, + ClientStreams: true, + } + stream, err := c.cc.NewStream(ctx, desc, "/grpc.lb.v1.LoadBalancer/BalanceLoad", opts...) + if err != nil { + return nil, err + } + x := &balanceLoadClientStream{stream} + return x, nil +} + +type balanceLoadClientStream struct { + ClientStream +} + +func (x *balanceLoadClientStream) Send(m *lbpb.LoadBalanceRequest) error { + return x.ClientStream.SendMsg(m) +} + +func (x *balanceLoadClientStream) Recv() (*lbpb.LoadBalanceResponse, error) { + m := new(lbpb.LoadBalanceResponse) + if err := x.ClientStream.RecvMsg(m); err != nil { + return nil, err + } + return m, nil +} + +func init() { + balancer.Register(newLBBuilder()) +} + +// newLBBuilder creates a builder for grpclb. +func newLBBuilder() balancer.Builder { + return NewLBBuilderWithFallbackTimeout(defaultFallbackTimeout) +} + +// NewLBBuilderWithFallbackTimeout creates a grpclb builder with the given +// fallbackTimeout. If no response is received from the remote balancer within +// fallbackTimeout, the backend addresses from the resolved address list will be +// used. +// +// Only call this function when a non-default fallback timeout is needed. +func NewLBBuilderWithFallbackTimeout(fallbackTimeout time.Duration) balancer.Builder { + return &lbBuilder{ + fallbackTimeout: fallbackTimeout, + } +} + +type lbBuilder struct { + fallbackTimeout time.Duration +} + +func (b *lbBuilder) Name() string { + return grpclbName +} + +func (b *lbBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer { + // This generates a manual resolver builder with a random scheme. This + // scheme will be used to dial to remote LB, so we can send filtered address + // updates to remote LB ClientConn using this manual resolver. + scheme := "grpclb_internal_" + strconv.FormatInt(time.Now().UnixNano(), 36) + r := &lbManualResolver{scheme: scheme, ccb: cc} + + var target string + targetSplitted := strings.Split(cc.Target(), ":///") + if len(targetSplitted) < 2 { + target = cc.Target() + } else { + target = targetSplitted[1] + } + + lb := &lbBalancer{ + cc: newLBCacheClientConn(cc), + target: target, + opt: opt, + fallbackTimeout: b.fallbackTimeout, + doneCh: make(chan struct{}), + + manualResolver: r, + csEvltr: &connectivityStateEvaluator{}, + subConns: make(map[resolver.Address]balancer.SubConn), + scStates: make(map[balancer.SubConn]connectivity.State), + picker: &errPicker{err: balancer.ErrNoSubConnAvailable}, + clientStats: &rpcStats{}, + } + + return lb +} + +type lbBalancer struct { + cc *lbCacheClientConn + target string + opt balancer.BuildOptions + fallbackTimeout time.Duration + doneCh chan struct{} + + // manualResolver is used in the remote LB ClientConn inside grpclb. When + // resolved address updates are received by grpclb, filtered updates will be + // send to remote LB ClientConn through this resolver. + manualResolver *lbManualResolver + // The ClientConn to talk to the remote balancer. + ccRemoteLB *ClientConn + + // Support client side load reporting. Each picker gets a reference to this, + // and will update its content. + clientStats *rpcStats + + mu sync.Mutex // guards everything following. + // The full server list including drops, used to check if the newly received + // serverList contains anything new. Each generate picker will also have + // reference to this list to do the first layer pick. + fullServerList []*lbpb.Server + // All backends addresses, with metadata set to nil. This list contains all + // backend addresses in the same order and with the same duplicates as in + // serverlist. When generating picker, a SubConn slice with the same order + // but with only READY SCs will be gerenated. + backendAddrs []resolver.Address + // Roundrobin functionalities. + csEvltr *connectivityStateEvaluator + state connectivity.State + subConns map[resolver.Address]balancer.SubConn // Used to new/remove SubConn. + scStates map[balancer.SubConn]connectivity.State // Used to filter READY SubConns. + picker balancer.Picker + // Support fallback to resolved backend addresses if there's no response + // from remote balancer within fallbackTimeout. + fallbackTimerExpired bool + serverListReceived bool + // resolvedBackendAddrs is resolvedAddrs minus remote balancers. It's set + // when resolved address updates are received, and read in the goroutine + // handling fallback. + resolvedBackendAddrs []resolver.Address +} + +// regeneratePicker takes a snapshot of the balancer, and generates a picker from +// it. The picker +// - always returns ErrTransientFailure if the balancer is in TransientFailure, +// - does two layer roundrobin pick otherwise. +// Caller must hold lb.mu. +func (lb *lbBalancer) regeneratePicker() { + if lb.state == connectivity.TransientFailure { + lb.picker = &errPicker{err: balancer.ErrTransientFailure} + return + } + var readySCs []balancer.SubConn + for _, a := range lb.backendAddrs { + if sc, ok := lb.subConns[a]; ok { + if st, ok := lb.scStates[sc]; ok && st == connectivity.Ready { + readySCs = append(readySCs, sc) + } + } + } + + if len(lb.fullServerList) <= 0 { + if len(readySCs) <= 0 { + lb.picker = &errPicker{err: balancer.ErrNoSubConnAvailable} + return + } + lb.picker = &rrPicker{subConns: readySCs} + return + } + lb.picker = &lbPicker{ + serverList: lb.fullServerList, + subConns: readySCs, + stats: lb.clientStats, + } +} + +func (lb *lbBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) { + grpclog.Infof("lbBalancer: handle SubConn state change: %p, %v", sc, s) + lb.mu.Lock() + defer lb.mu.Unlock() + + oldS, ok := lb.scStates[sc] + if !ok { + grpclog.Infof("lbBalancer: got state changes for an unknown SubConn: %p, %v", sc, s) + return + } + lb.scStates[sc] = s + switch s { + case connectivity.Idle: + sc.Connect() + case connectivity.Shutdown: + // When an address was removed by resolver, b called RemoveSubConn but + // kept the sc's state in scStates. Remove state for this sc here. + delete(lb.scStates, sc) + } + + oldAggrState := lb.state + lb.state = lb.csEvltr.recordTransition(oldS, s) + + // Regenerate picker when one of the following happens: + // - this sc became ready from not-ready + // - this sc became not-ready from ready + // - the aggregated state of balancer became TransientFailure from non-TransientFailure + // - the aggregated state of balancer became non-TransientFailure from TransientFailure + if (oldS == connectivity.Ready) != (s == connectivity.Ready) || + (lb.state == connectivity.TransientFailure) != (oldAggrState == connectivity.TransientFailure) { + lb.regeneratePicker() + } + + lb.cc.UpdateBalancerState(lb.state, lb.picker) +} + +// fallbackToBackendsAfter blocks for fallbackTimeout and falls back to use +// resolved backends (backends received from resolver, not from remote balancer) +// if no connection to remote balancers was successful. +func (lb *lbBalancer) fallbackToBackendsAfter(fallbackTimeout time.Duration) { + timer := time.NewTimer(fallbackTimeout) + defer timer.Stop() + select { + case <-timer.C: + case <-lb.doneCh: + return + } + lb.mu.Lock() + if lb.serverListReceived { + lb.mu.Unlock() + return + } + lb.fallbackTimerExpired = true + lb.refreshSubConns(lb.resolvedBackendAddrs) + lb.mu.Unlock() +} + +// HandleResolvedAddrs sends the updated remoteLB addresses to remoteLB +// clientConn. The remoteLB clientConn will handle creating/removing remoteLB +// connections. +func (lb *lbBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) { + grpclog.Infof("lbBalancer: handleResolvedResult: %+v", addrs) + if len(addrs) <= 0 { + return + } + + var remoteBalancerAddrs, backendAddrs []resolver.Address + for _, a := range addrs { + if a.Type == resolver.GRPCLB { + remoteBalancerAddrs = append(remoteBalancerAddrs, a) + } else { + backendAddrs = append(backendAddrs, a) + } + } + + if lb.ccRemoteLB == nil { + if len(remoteBalancerAddrs) <= 0 { + grpclog.Errorf("grpclb: no remote balancer address is available, should never happen") + return + } + // First time receiving resolved addresses, create a cc to remote + // balancers. + lb.dialRemoteLB(remoteBalancerAddrs[0].ServerName) + // Start the fallback goroutine. + go lb.fallbackToBackendsAfter(lb.fallbackTimeout) + } + + // cc to remote balancers uses lb.manualResolver. Send the updated remote + // balancer addresses to it through manualResolver. + lb.manualResolver.NewAddress(remoteBalancerAddrs) + + lb.mu.Lock() + lb.resolvedBackendAddrs = backendAddrs + // If serverListReceived is true, connection to remote balancer was + // successful and there's no need to do fallback anymore. + // If fallbackTimerExpired is false, fallback hasn't happened yet. + if !lb.serverListReceived && lb.fallbackTimerExpired { + // This means we received a new list of resolved backends, and we are + // still in fallback mode. Need to update the list of backends we are + // using to the new list of backends. + lb.refreshSubConns(lb.resolvedBackendAddrs) + } + lb.mu.Unlock() +} + +func (lb *lbBalancer) Close() { + select { + case <-lb.doneCh: + return + default: + } + close(lb.doneCh) + if lb.ccRemoteLB != nil { + lb.ccRemoteLB.Close() + } + lb.cc.close() +} -- cgit v1.2.3-1-g7c22