grpc server从client中获取超时信息

在grpc server中进行超时控制，需要感知客户端的超时时间。本文将对grpc client,http两种访问方式下如何给grpc server传递超时时间进行总结。

grpc client传递超时时间

在client发起调用时，通过使用带timeout的context，可将超时信息传递给server。

验证代码

client端

ctx, cancel := context.WithTimeout(ctx, 2*time.Second)
go func() {
	time.Sleep(1 * time.Second)
	cancel()
}()
if err := client.SayHello(ctx, &hello.SayHelloRequest{
	Message: "hello world",
}); err != nil {
	logger.Error(ctx, "SayHello", zap.Error(err))
	return
}

server端

func doSomething(somethingDone chan<- struct{}) {
	time.Sleep(10 * time.Second)
	somethingDone <- struct{}{}
}

// inside handler
if ddl, ok := ctx.Deadline(); ok {
		log.Printf("deadline set: %+v", ddl)
	}
	somethingDone := make(chan struct{})
	go doSomething(somethingDone)
	// set timeout to 2 seconds on client side
	for {
		select {
		case <-ctx.Done():
			log.Printf("!!! context cancel")
			return nil, ctx.Err()
		case <-somethingDone:
			goto after
		default:
		}
	}
after:
	return &hello.SayHelloResponse{Message: r.Message}, nil

client输出

2023/08/27 21:10:22 ### ready to invoke SayHello ###
{"level":"error","ts":"2023-08-27T21:10:23.496+0800","caller":"logger/interface.go:21","msg":"SayHello","error":"rpc error: code = Canceled desc = context canceled","stacktrace":"github.com/brickzzhang/grpc-helloworld/workshop/logger.Error\n\t/Users/bytedance/personalspace/grpc-helloworld/workshop/logger/interface.go:21\nmain.main\n\t/Users/bytedance/personalspace/grpc-helloworld/client/client.go:61\nruntime.main\n\t/opt/homebrew/Cellar/go/1.21.0/libexec/src/runtime/proc.go:267"}

server输出

2023/08/27 21:10:22 deadline set: 2023-08-27 21:10:24.496345 +0800 CST m=+458.621381042
2023/08/27 21:10:23 !!! context cancel
{"level":"error","ts":"2023-08-27T21:10:23.497+0800","caller":"zap/server_interceptors.go:40","msg":"finished unary call with code Unknown","peer.address":"127.0.0.1:49311","grpc.start_time":"2023-08-27T21:10:22+08:00","grpc.request.deadline":"2023-08-27T21:10:24+08:00","system":"grpc","span.kind":"server","grpc.service":"helloworld.HelloWorldService","grpc.method":"SayHello","peer.address":"127.0.0.1:49311","error":"context canceled","grpc.code":"Unknown","grpc.time_ms":998.697021484375,"stacktrace":"github.com/grpc-ecosystem/go-grpc-middleware/logging/zap.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/logging/zap/server_interceptors.go:40\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/tags.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go:21\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/recovery.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/recovery/interceptors.go:29\nmain.startServer.ChainUnaryServer.func6\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:39\ngithub.com/brickzzhang/grpc-helloworld/apigen/hello._HelloWorldService_SayHello_Handler\n\t/Users/bytedance/personalspace/grpc-helloworld/apigen/hello/helloworld_grpc.pb.go:267\ngoogle.golang.org/grpc.(*Server).processUnaryRPC\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1283\ngoogle.golang.org/grpc.(*Server).handleStream\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1620\ngoogle.golang.org/grpc.(*Server).serveStreams.func1.2\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:922"}

验证结论

使用grpc方式调用时，当client端的context设置过超时信息，超时信息会通过context传到server端。

grpc-gateway传递超时时间

验证代码

调用方

curl localhost:8081/v1/helloworld -d '{"message": "test"}' -H 'grpc-timeout:1S' -X POST

server端代码

func doSomething(somethingDone chan<- struct{}) {
	time.Sleep(10 * time.Second)
	somethingDone <- struct{}{}
}

// inside handler
if ddl, ok := ctx.Deadline(); ok {
		log.Printf("deadline set: %+v", ddl)
	}
	somethingDone := make(chan struct{})
	go doSomething(somethingDone)
	// set timeout to 2 seconds on client side
	for {
		select {
		case <-ctx.Done():
			log.Printf("!!! context cancel")
			return nil, ctx.Err()
		case <-somethingDone:
			goto after
		default:
		}
	}
after:
	return &hello.SayHelloResponse{Message: r.Message}, nil

client输出

{"code":4,"data":null,"error":"context deadline exceeded"}%

server输出

2023/08/27 22:10:34 deadline set: 2023-08-27 22:10:35.685275 +0800 CST m=+2903.421145001
2023/08/27 22:10:35 !!! context cancel
{"level":"error","ts":"2023-08-27T22:10:35.686+0800","caller":"zap/server_interceptors.go:40","msg":"finished unary call with code Unknown","peer.address":"127.0.0.1:49198","grpc.start_time":"2023-08-27T22:10:34+08:00","grpc.request.deadline":"2023-08-27T22:10:35+08:00","system":"grpc","span.kind":"server","grpc.service":"helloworld.HelloWorldService","grpc.method":"SayHello","peer.address":"127.0.0.1:49198","error":"context deadline exceeded","grpc.code":"Unknown","grpc.time_ms":1000.969970703125,"stacktrace":"github.com/grpc-ecosystem/go-grpc-middleware/logging/zap.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/logging/zap/server_interceptors.go:40\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/tags.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go:21\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/recovery.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/recovery/interceptors.go:29\nmain.startServer.ChainUnaryServer.func6\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:39\ngithub.com/brickzzhang/grpc-helloworld/apigen/hello._HelloWorldService_SayHello_Handler\n\t/Users/bytedance/personalspace/grpc-helloworld/apigen/hello/helloworld_grpc.pb.go:267\ngoogle.golang.org/grpc.(*Server).processUnaryRPC\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1283\ngoogle.golang.org/grpc.(*Server).handleStream\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1620\ngoogle.golang.org/grpc.(*Server).serveStreams.func1.2\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:922"}

验证结论

当通过http方式，可通过添加grpc-timeout header将超时时间传递给server，具体格式可参考grpc doc

客户端断连超时

当客户端连接断开时，服务端也会立即收到超时信号。

调用方

curl localhost:8081/v1/helloworld -d '{"message": "test"}' -X POST
^C

server端代码

func doSomething(somethingDone chan<- struct{}) {
	time.Sleep(10 * time.Second)
	somethingDone <- struct{}{}
}

// inside handler
if ddl, ok := ctx.Deadline(); ok {
		log.Printf("deadline set: %+v", ddl)
	}
	somethingDone := make(chan struct{})
	go doSomething(somethingDone)
	// set timeout to 2 seconds on client side
	for {
		select {
		case <-ctx.Done():
			log.Printf("!!! context cancel")
			return nil, ctx.Err()
		case <-somethingDone:
			goto after
		default:
		}
	}
after:
	return &hello.SayHelloResponse{Message: r.Message}, nil

server输出

2023/08/27 22:22:31 !!! context cancel
{"level":"error","ts":"2023-08-27T22:22:31.627+0800","caller":"zap/server_interceptors.go:40","msg":"finished unary call with code Unknown","peer.address":"127.0.0.1:49198","grpc.start_time":"2023-08-27T22:22:30+08:00","system":"grpc","span.kind":"server","grpc.service":"helloworld.HelloWorldService","grpc.method":"SayHello","peer.address":"127.0.0.1:49198","error":"context canceled","grpc.code":"Unknown","grpc.time_ms":888.677001953125,"stacktrace":"github.com/grpc-ecosystem/go-grpc-middleware/logging/zap.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/logging/zap/server_interceptors.go:40\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/tags.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go:21\nmain.startServer.ChainUnaryServer.func6.1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34\ngithub.com/grpc-ecosystem/go-grpc-middleware/recovery.UnaryServerInterceptor.func1\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/recovery/interceptors.go:29\nmain.startServer.ChainUnaryServer.func6\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:39\ngithub.com/brickzzhang/grpc-helloworld/apigen/hello._HelloWorldService_SayHello_Handler\n\t/Users/bytedance/personalspace/grpc-helloworld/apigen/hello/helloworld_grpc.pb.go:267\ngoogle.golang.org/grpc.(*Server).processUnaryRPC\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1283\ngoogle.golang.org/grpc.(*Server).handleStream\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:1620\ngoogle.golang.org/grpc.(*Server).serveStreams.func1.2\n\t/Users/bytedance/personalspace/grpc-helloworld/vendor/google.golang.org/grpc/server.go:922"}

验证结论

当client端连接断开时，server端同样会收到超时信号，可通过context捕获处理。

代码路径

Demo代码可参考grpc-helloworld

参考

grpc超时传递原理

How to set a timeout in grpc-gateway

gRPC over HTTP2