Client 复用同个连接，出现 rpc error: code = Unknown desc =

[eddycjy]

问题

客户端复用 ClientConn 后，无法再次调用 RPC 方法成功

server

直接使用 greeter_server.php

client

直接改造 greeter_client.go，如下：

package main

import (
	"log"
	"os"

	"golang.org/x/net/context"
	"google.golang.org/grpc"
	pb "google.golang.org/grpc/examples/helloworld/helloworld"
)

const (
	address     = "localhost:50051"
	defaultName = "world"
)

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

	// Contact the server and print out its response.
	name := defaultName
	if len(os.Args) > 1 {
		name = os.Args[1]
	}
	r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
	if err != nil {
		log.Fatalf("could not greet1: %v", err)
	}
	log.Printf("Greeting: %s", r.Message)

	r, err = c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
	if err != nil {
		log.Fatalf("could not greet2: %v", err)
	}
	log.Printf("Greeting: %s", r.Message)
}

输出结果

$ go run greeter_client.go
2019/04/18 14:18:06 Greeting: Hello world
2019/04/18 14:18:06 could not greet2: rpc error: code = Unknown desc = 
exit status 1

[eddycjy]

PHP 版本

$ php -v
PHP 7.2.11 (cli) (built: Oct 21 2018 18:28:44) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.11, Copyright (c) 1999-2018, by Zend Technologies

Swoole 版本

$ php --ri swoole

swoole

swoole support => enabled
Version => 4.2.3
Author => Swoole Group[email: [email protected]]
coroutine => enabled
kqueue => enabled
rwlock => enabled
sockets => enabled
openssl => OpenSSL 1.0.2p  14 Aug 2018
http2 => 1.34.0
pcre => enabled
zlib => enabled
brotli => enabled

Directive => Local Value => Master Value
swoole.enable_coroutine => On => On
swoole.aio_thread_num => 2 => 2
swoole.display_errors => On => On
swoole.use_namespace => On => On
swoole.use_shortname => On => On
swoole.fast_serialize => Off => Off
swoole.unixsock_buffer_size => 8388608 => 8388608

Go 版本

$ go version
go version go1.11.5 darwin/amd64

[mmaxiaolei]

@eddycjy 请问这个问题有解决吗？麻烦分享一下解决方法

[zewenying]

可以试下在client端和server端增加以下配置：
ClientParameters.PermitWithoutStream=true
EnforcementPolicy. PermitWithoutStream=true
参考链接：https://godoc.org/google.golang.org/grpc/keepalive