go - gRPC - GoLang - Stackdriver 追踪器

Question

我正在尝试获取 stackdriver与 gRPC 配合使用的示踪剂我需要一些帮助。我一直在查看这两个链接以供引用，但仍然无法正常工作:

• https://medium.com/@harlow/tracing-grpc-calls-in-golang-with-google-stackdriver-b22495763a06#.81oa9q21v
• https://rakyll.org/grpc-trace/

为简单起见，我只使用 hello world gRPC example .这是我的客户:

func main() {

    // Set up a connection to the server.
    conn, err := grpc.Dial("localhost:50051", grpc.WithInsecure(), grpc.WithUnaryInterceptor(grpc.UnaryClientInterceptor(clientInterceptor)))
    if err != nil {
        log.Fatalf("did not connect: %v", err)
    }
    defer conn.Close()
    c := pb.NewGreeterClient(conn)

    ctx := context.Background()

    tc, err := trace.NewClient(ctx, "{PROJECT-ID}")
    if err != nil {
        log.Fatal(err)
    }

    span := tc.NewSpan("/greeter/SayHello")
    defer span.Finish()

    ctx = trace.NewContext(ctx, span)

    r, err := c.SayHello(ctx, &pb.HelloRequest{Name: "world"})
    if err != nil {
        log.Fatalf("could not greet: %v", err)
    }

    println("Response:", r.Message)
}

func clientInterceptor(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
    // trace current request w/ child span
    span := trace.FromContext(ctx).NewChild(method)
    defer span.Finish()

    // new metadata, or copy of existing
    md, ok := metadata.FromContext(ctx)
    if !ok {
        md = metadata.New(nil)
    } else {
        md = md.Copy()
    }

    // append trace header to context metadata
    // header specification: https://cloud.google.com/trace/docs/faq
    md["X-Cloud-Trace-Context"] = append(
        md["X-Cloud-Trace-Context"], fmt.Sprintf("%s/%d;o=1", span.TraceID(), 0),
    )
    ctx = metadata.NewContext(ctx, md)

    return invoker(ctx, method, req, reply, cc, opts...)
}

.. 和我的 gRPC 服务器:

// server is used to implement helloworld.GreeterServer.
type server struct{}

// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    println("HERE")
    return &pb.HelloReply{Message: "Hello " + in.Name}, nil
}

func main() {
    lis, err := net.Listen("tcp", ":50051")
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }

    ctx := context.Background()
    tc, err := trace.NewClient(ctx, "{PROJECT-ID}")
    if err != nil {
        log.Fatal(err)
    }

    s := grpc.NewServer(EnableGRPCTracingServerOption(tc))
    pb.RegisterGreeterServer(s, &server{})

    println("listening on :50051")
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

// EnableGRPCTracingServerOption enables parsing google trace header from metadata
// and adds a new child span to the incoming request context.
func EnableGRPCTracingServerOption(traceClient *trace.Client) grpc.ServerOption {
    return grpc.UnaryInterceptor(serverInterceptor(traceClient))
}

func serverInterceptor(traceClient *trace.Client) grpc.UnaryServerInterceptor {
    return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
        // fetch metadata from request context
        md, ok := metadata.FromContext(ctx)
        if !ok {
            md = metadata.New(nil)
        }
        header := strings.Join(md["X-Cloud-Trace-Context"], "")

        // create new child span from google trace header, add to
        // current request context
        span := traceClient.SpanFromHeader(info.FullMethod, header)
        defer span.Finish()
        ctx = trace.NewContext(ctx, span)

        return handler(ctx, req)
    }
}

当我运行客户端启动跟踪时，出现错误:

rpc error: code = 13 desc = stream terminated by RST_STREAM with error code: 1

我很困惑，因为我没有看到任何关于身份验证的信息；仅提供项目 ID 不足以启动对特定项目的跟踪。我错过了什么？

Answer 1

问题在于:

defer span.Finish()

该调用不会阻塞，因为我只是通过一个调用进行初步测试，我的程序在跟踪可以上传之前退出。我联系了 https://rakyll.org/grpc-trace/ 的作者她实际上使用以下选项更新了她的帖子:

defer span.FinishWait()

哪些 block 和哪些通过允许在程序退出之前成功上传跟踪来修复它。

此外，对于长时间运行的网络服务器，这不会成为问题，因为进程不会终止。