From 15c0b25d011f37e7c20aeca9eaf461f78285b8d9 Mon Sep 17 00:00:00 2001 From: Alex Pilon Date: Fri, 22 Feb 2019 18:24:37 -0500 Subject: deps: github.com/hashicorp/terraform@sdk-v0.11-with-go-modules Updated via: go get github.com/hashicorp/terraform@sdk-v0.11-with-go-modules and go mod tidy --- vendor/google.golang.org/grpc/grpclb.go | 737 ++++++++++++++++++++++++++++++++ 1 file changed, 737 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 0000000..f7b6b7d --- /dev/null +++ b/vendor/google.golang.org/grpc/grpclb.go @@ -0,0 +1,737 @@ +/* + * + * 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 ( + "errors" + "fmt" + "math/rand" + "net" + "sync" + "time" + + "golang.org/x/net/context" + "google.golang.org/grpc/codes" + lbpb "google.golang.org/grpc/grpclb/grpc_lb_v1" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/naming" +) + +// 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 := NewClientStream(ctx, desc, c.cc, "/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 +} + +// NewGRPCLBBalancer creates a grpclb load balancer. +func NewGRPCLBBalancer(r naming.Resolver) Balancer { + return &balancer{ + r: r, + } +} + +type remoteBalancerInfo struct { + addr string + // the server name used for authentication with the remote LB server. + name string +} + +// grpclbAddrInfo consists of the information of a backend server. +type grpclbAddrInfo struct { + addr Address + connected bool + // dropForRateLimiting indicates whether this particular request should be + // dropped by the client for rate limiting. + dropForRateLimiting bool + // dropForLoadBalancing indicates whether this particular request should be + // dropped by the client for load balancing. + dropForLoadBalancing bool +} + +type balancer struct { + r naming.Resolver + target string + mu sync.Mutex + seq int // a sequence number to make sure addrCh does not get stale addresses. + w naming.Watcher + addrCh chan []Address + rbs []remoteBalancerInfo + addrs []*grpclbAddrInfo + next int + waitCh chan struct{} + done bool + expTimer *time.Timer + rand *rand.Rand + + clientStats lbpb.ClientStats +} + +func (b *balancer) watchAddrUpdates(w naming.Watcher, ch chan []remoteBalancerInfo) error { + updates, err := w.Next() + if err != nil { + grpclog.Warningf("grpclb: failed to get next addr update from watcher: %v", err) + return err + } + b.mu.Lock() + defer b.mu.Unlock() + if b.done { + return ErrClientConnClosing + } + for _, update := range updates { + switch update.Op { + case naming.Add: + var exist bool + for _, v := range b.rbs { + // TODO: Is the same addr with different server name a different balancer? + if update.Addr == v.addr { + exist = true + break + } + } + if exist { + continue + } + md, ok := update.Metadata.(*naming.AddrMetadataGRPCLB) + if !ok { + // TODO: Revisit the handling here and may introduce some fallback mechanism. + grpclog.Errorf("The name resolution contains unexpected metadata %v", update.Metadata) + continue + } + switch md.AddrType { + case naming.Backend: + // TODO: Revisit the handling here and may introduce some fallback mechanism. + grpclog.Errorf("The name resolution does not give grpclb addresses") + continue + case naming.GRPCLB: + b.rbs = append(b.rbs, remoteBalancerInfo{ + addr: update.Addr, + name: md.ServerName, + }) + default: + grpclog.Errorf("Received unknow address type %d", md.AddrType) + continue + } + case naming.Delete: + for i, v := range b.rbs { + if update.Addr == v.addr { + copy(b.rbs[i:], b.rbs[i+1:]) + b.rbs = b.rbs[:len(b.rbs)-1] + break + } + } + default: + grpclog.Errorf("Unknown update.Op %v", update.Op) + } + } + // TODO: Fall back to the basic round-robin load balancing if the resulting address is + // not a load balancer. + select { + case <-ch: + default: + } + ch <- b.rbs + return nil +} + +func (b *balancer) serverListExpire(seq int) { + b.mu.Lock() + defer b.mu.Unlock() + // TODO: gRPC interanls do not clear the connections when the server list is stale. + // This means RPCs will keep using the existing server list until b receives new + // server list even though the list is expired. Revisit this behavior later. + if b.done || seq < b.seq { + return + } + b.next = 0 + b.addrs = nil + // Ask grpc internals to close all the corresponding connections. + b.addrCh <- nil +} + +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 +} + +func (b *balancer) processServerList(l *lbpb.ServerList, seq int) { + if l == nil { + return + } + servers := l.GetServers() + expiration := convertDuration(l.GetExpirationInterval()) + var ( + sl []*grpclbAddrInfo + addrs []Address + ) + for _, s := range servers { + md := metadata.Pairs("lb-token", s.LoadBalanceToken) + ip := net.IP(s.IpAddress) + ipStr := ip.String() + if ip.To4() == nil { + // Add square brackets to ipv6 addresses, otherwise net.Dial() and + // net.SplitHostPort() will return too many colons error. + ipStr = fmt.Sprintf("[%s]", ipStr) + } + addr := Address{ + Addr: fmt.Sprintf("%s:%d", ipStr, s.Port), + Metadata: &md, + } + sl = append(sl, &grpclbAddrInfo{ + addr: addr, + dropForRateLimiting: s.DropForRateLimiting, + dropForLoadBalancing: s.DropForLoadBalancing, + }) + addrs = append(addrs, addr) + } + b.mu.Lock() + defer b.mu.Unlock() + if b.done || seq < b.seq { + return + } + if len(sl) > 0 { + // reset b.next to 0 when replacing the server list. + b.next = 0 + b.addrs = sl + b.addrCh <- addrs + if b.expTimer != nil { + b.expTimer.Stop() + b.expTimer = nil + } + if expiration > 0 { + b.expTimer = time.AfterFunc(expiration, func() { + b.serverListExpire(seq) + }) + } + } + return +} + +func (b *balancer) sendLoadReport(s *balanceLoadClientStream, interval time.Duration, done <-chan struct{}) { + ticker := time.NewTicker(interval) + defer ticker.Stop() + for { + select { + case <-ticker.C: + case <-done: + return + } + b.mu.Lock() + stats := b.clientStats + b.clientStats = lbpb.ClientStats{} // Clear the stats. + b.mu.Unlock() + t := time.Now() + stats.Timestamp = &lbpb.Timestamp{ + Seconds: t.Unix(), + Nanos: int32(t.Nanosecond()), + } + if err := s.Send(&lbpb.LoadBalanceRequest{ + LoadBalanceRequestType: &lbpb.LoadBalanceRequest_ClientStats{ + ClientStats: &stats, + }, + }); err != nil { + grpclog.Errorf("grpclb: failed to send load report: %v", err) + return + } + } +} + +func (b *balancer) callRemoteBalancer(lbc *loadBalancerClient, seq int) (retry bool) { + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + stream, err := lbc.BalanceLoad(ctx) + if err != nil { + grpclog.Errorf("grpclb: failed to perform RPC to the remote balancer %v", err) + return + } + b.mu.Lock() + if b.done { + b.mu.Unlock() + return + } + b.mu.Unlock() + initReq := &lbpb.LoadBalanceRequest{ + LoadBalanceRequestType: &lbpb.LoadBalanceRequest_InitialRequest{ + InitialRequest: &lbpb.InitialLoadBalanceRequest{ + Name: b.target, + }, + }, + } + if err := stream.Send(initReq); err != nil { + grpclog.Errorf("grpclb: failed to send init request: %v", err) + // TODO: backoff on retry? + return true + } + reply, err := stream.Recv() + if err != nil { + grpclog.Errorf("grpclb: failed to recv init response: %v", err) + // TODO: backoff on retry? + return true + } + initResp := reply.GetInitialResponse() + if initResp == nil { + grpclog.Errorf("grpclb: reply from remote balancer did not include initial response.") + return + } + // TODO: Support delegation. + if initResp.LoadBalancerDelegate != "" { + // delegation + grpclog.Errorf("TODO: Delegation is not supported yet.") + return + } + streamDone := make(chan struct{}) + defer close(streamDone) + b.mu.Lock() + b.clientStats = lbpb.ClientStats{} // Clear client stats. + b.mu.Unlock() + if d := convertDuration(initResp.ClientStatsReportInterval); d > 0 { + go b.sendLoadReport(stream, d, streamDone) + } + // Retrieve the server list. + for { + reply, err := stream.Recv() + if err != nil { + grpclog.Errorf("grpclb: failed to recv server list: %v", err) + break + } + b.mu.Lock() + if b.done || seq < b.seq { + b.mu.Unlock() + return + } + b.seq++ // tick when receiving a new list of servers. + seq = b.seq + b.mu.Unlock() + if serverList := reply.GetServerList(); serverList != nil { + b.processServerList(serverList, seq) + } + } + return true +} + +func (b *balancer) Start(target string, config BalancerConfig) error { + b.rand = rand.New(rand.NewSource(time.Now().Unix())) + // TODO: Fall back to the basic direct connection if there is no name resolver. + if b.r == nil { + return errors.New("there is no name resolver installed") + } + b.target = target + b.mu.Lock() + if b.done { + b.mu.Unlock() + return ErrClientConnClosing + } + b.addrCh = make(chan []Address) + w, err := b.r.Resolve(target) + if err != nil { + b.mu.Unlock() + grpclog.Errorf("grpclb: failed to resolve address: %v, err: %v", target, err) + return err + } + b.w = w + b.mu.Unlock() + balancerAddrsCh := make(chan []remoteBalancerInfo, 1) + // Spawn a goroutine to monitor the name resolution of remote load balancer. + go func() { + for { + if err := b.watchAddrUpdates(w, balancerAddrsCh); err != nil { + grpclog.Warningf("grpclb: the naming watcher stops working due to %v.\n", err) + close(balancerAddrsCh) + return + } + } + }() + // Spawn a goroutine to talk to the remote load balancer. + go func() { + var ( + cc *ClientConn + // ccError is closed when there is an error in the current cc. + // A new rb should be picked from rbs and connected. + ccError chan struct{} + rb *remoteBalancerInfo + rbs []remoteBalancerInfo + rbIdx int + ) + + defer func() { + if ccError != nil { + select { + case <-ccError: + default: + close(ccError) + } + } + if cc != nil { + cc.Close() + } + }() + + for { + var ok bool + select { + case rbs, ok = <-balancerAddrsCh: + if !ok { + return + } + foundIdx := -1 + if rb != nil { + for i, trb := range rbs { + if trb == *rb { + foundIdx = i + break + } + } + } + if foundIdx >= 0 { + if foundIdx >= 1 { + // Move the address in use to the beginning of the list. + b.rbs[0], b.rbs[foundIdx] = b.rbs[foundIdx], b.rbs[0] + rbIdx = 0 + } + continue // If found, don't dial new cc. + } else if len(rbs) > 0 { + // Pick a random one from the list, instead of always using the first one. + if l := len(rbs); l > 1 && rb != nil { + tmpIdx := b.rand.Intn(l - 1) + b.rbs[0], b.rbs[tmpIdx] = b.rbs[tmpIdx], b.rbs[0] + } + rbIdx = 0 + rb = &rbs[0] + } else { + // foundIdx < 0 && len(rbs) <= 0. + rb = nil + } + case <-ccError: + ccError = nil + if rbIdx < len(rbs)-1 { + rbIdx++ + rb = &rbs[rbIdx] + } else { + rb = nil + } + } + + if rb == nil { + continue + } + + if cc != nil { + cc.Close() + } + // Talk to the remote load balancer to get the server list. + var ( + err error + dopts []DialOption + ) + if creds := config.DialCreds; creds != nil { + if rb.name != "" { + if err := creds.OverrideServerName(rb.name); err != nil { + grpclog.Warningf("grpclb: failed to override the server name in the credentials: %v", err) + continue + } + } + dopts = append(dopts, WithTransportCredentials(creds)) + } else { + dopts = append(dopts, WithInsecure()) + } + if dialer := config.Dialer; dialer != nil { + // WithDialer takes a different type of function, so we instead use a special DialOption here. + dopts = append(dopts, func(o *dialOptions) { o.copts.Dialer = dialer }) + } + ccError = make(chan struct{}) + cc, err = Dial(rb.addr, dopts...) + if err != nil { + grpclog.Warningf("grpclb: failed to setup a connection to the remote balancer %v: %v", rb.addr, err) + close(ccError) + continue + } + b.mu.Lock() + b.seq++ // tick when getting a new balancer address + seq := b.seq + b.next = 0 + b.mu.Unlock() + go func(cc *ClientConn, ccError chan struct{}) { + lbc := &loadBalancerClient{cc} + b.callRemoteBalancer(lbc, seq) + cc.Close() + select { + case <-ccError: + default: + close(ccError) + } + }(cc, ccError) + } + }() + return nil +} + +func (b *balancer) down(addr Address, err error) { + b.mu.Lock() + defer b.mu.Unlock() + for _, a := range b.addrs { + if addr == a.addr { + a.connected = false + break + } + } +} + +func (b *balancer) Up(addr Address) func(error) { + b.mu.Lock() + defer b.mu.Unlock() + if b.done { + return nil + } + var cnt int + for _, a := range b.addrs { + if a.addr == addr { + if a.connected { + return nil + } + a.connected = true + } + if a.connected && !a.dropForRateLimiting && !a.dropForLoadBalancing { + cnt++ + } + } + // addr is the only one which is connected. Notify the Get() callers who are blocking. + if cnt == 1 && b.waitCh != nil { + close(b.waitCh) + b.waitCh = nil + } + return func(err error) { + b.down(addr, err) + } +} + +func (b *balancer) Get(ctx context.Context, opts BalancerGetOptions) (addr Address, put func(), err error) { + var ch chan struct{} + b.mu.Lock() + if b.done { + b.mu.Unlock() + err = ErrClientConnClosing + return + } + seq := b.seq + + defer func() { + if err != nil { + return + } + put = func() { + s, ok := rpcInfoFromContext(ctx) + if !ok { + return + } + b.mu.Lock() + defer b.mu.Unlock() + if b.done || seq < b.seq { + return + } + b.clientStats.NumCallsFinished++ + if !s.bytesSent { + b.clientStats.NumCallsFinishedWithClientFailedToSend++ + } else if s.bytesReceived { + b.clientStats.NumCallsFinishedKnownReceived++ + } + } + }() + + b.clientStats.NumCallsStarted++ + if len(b.addrs) > 0 { + if b.next >= len(b.addrs) { + b.next = 0 + } + next := b.next + for { + a := b.addrs[next] + next = (next + 1) % len(b.addrs) + if a.connected { + if !a.dropForRateLimiting && !a.dropForLoadBalancing { + addr = a.addr + b.next = next + b.mu.Unlock() + return + } + if !opts.BlockingWait { + b.next = next + if a.dropForLoadBalancing { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithDropForLoadBalancing++ + } else if a.dropForRateLimiting { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithDropForRateLimiting++ + } + b.mu.Unlock() + err = Errorf(codes.Unavailable, "%s drops requests", a.addr.Addr) + return + } + } + if next == b.next { + // Has iterated all the possible address but none is connected. + break + } + } + } + if !opts.BlockingWait { + if len(b.addrs) == 0 { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithClientFailedToSend++ + b.mu.Unlock() + err = Errorf(codes.Unavailable, "there is no address available") + return + } + // Returns the next addr on b.addrs for a failfast RPC. + addr = b.addrs[b.next].addr + b.next++ + b.mu.Unlock() + return + } + // Wait on b.waitCh for non-failfast RPCs. + if b.waitCh == nil { + ch = make(chan struct{}) + b.waitCh = ch + } else { + ch = b.waitCh + } + b.mu.Unlock() + for { + select { + case <-ctx.Done(): + b.mu.Lock() + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithClientFailedToSend++ + b.mu.Unlock() + err = ctx.Err() + return + case <-ch: + b.mu.Lock() + if b.done { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithClientFailedToSend++ + b.mu.Unlock() + err = ErrClientConnClosing + return + } + + if len(b.addrs) > 0 { + if b.next >= len(b.addrs) { + b.next = 0 + } + next := b.next + for { + a := b.addrs[next] + next = (next + 1) % len(b.addrs) + if a.connected { + if !a.dropForRateLimiting && !a.dropForLoadBalancing { + addr = a.addr + b.next = next + b.mu.Unlock() + return + } + if !opts.BlockingWait { + b.next = next + if a.dropForLoadBalancing { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithDropForLoadBalancing++ + } else if a.dropForRateLimiting { + b.clientStats.NumCallsFinished++ + b.clientStats.NumCallsFinishedWithDropForRateLimiting++ + } + b.mu.Unlock() + err = Errorf(codes.Unavailable, "drop requests for the addreess %s", a.addr.Addr) + return + } + } + if next == b.next { + // Has iterated all the possible address but none is connected. + break + } + } + } + // The newly added addr got removed by Down() again. + if b.waitCh == nil { + ch = make(chan struct{}) + b.waitCh = ch + } else { + ch = b.waitCh + } + b.mu.Unlock() + } + } +} + +func (b *balancer) Notify() <-chan []Address { + return b.addrCh +} + +func (b *balancer) Close() error { + b.mu.Lock() + defer b.mu.Unlock() + if b.done { + return errBalancerClosed + } + b.done = true + if b.expTimer != nil { + b.expTimer.Stop() + } + if b.waitCh != nil { + close(b.waitCh) + } + if b.addrCh != nil { + close(b.addrCh) + } + if b.w != nil { + b.w.Close() + } + return nil +} -- cgit v1.2.3