手撸golang GO与微服务 net.rpc之2
缘起
最近阅读 [Go微服务实战] (刘金亮, 2021.1)
本系列笔记拟采用golang练习之
gitee: https://gitee.com/ioly/learning.gooop
net/rpc
微服务中的进程间通信概述
对于进程间通信的技术，开发者有多种选择。
可以选择基于同步通信的通信机制，比如HTTP RESTful；
也可以选择基于异步通信的方式，Go语言提供了标准的net/rpc包以支持异步。
远程过程调用协议（Remote Procedure Call Protocol, RPC）,
是一种通过网络从远程计算机程序上请求服务，
而不需要了解底层网络技术的协议。目标(Day 2)
- Day 1的rpc测试是短连接，频繁dial和close非常影响吞吐，改为长连接版本看看
设计
- TimeConnection：封装rpc.dial以提供长连接的rpc.Client句柄。 rpc.Client.Call方法是并发安全的， 因此允许我们使用共享的长连接。
- ITimeClientV2: 时间客户端接口
- tTimeClientV2：时间客户端的实现， 持有长连接的rpc.Client句柄，进行远程GetTime调用
单元测试
- common.go，封装单元测试的通用代码
package net_rpc
import "testing"
func fnAssertTrue(t *testing.T, b bool, msg string) {
if !b {
t.Fatal(msg)
}
}
type CallLog struct {
done bool
cost int64
}- net_rpc_v2_test.go
- 使用TimeConnection提供的共享的长连接
- 并发100/300/500/1000/10000/50000次rpc调用
- 统计失败次数和平均耗时
package net_rpc
import (
"learning/gooop/net_rpc"
"sync"
"testing"
"time"
)
func Test_NetRPC_V2(t *testing.T) {
server := new(net_rpc.TimeServer)
err := server.Serve(3333)
if err != nil {
t.Fatal(err)
}
time.Sleep(100 * time.Millisecond)
fnTestRpcCall := func(client net_rpc.ITimeClientV2, log *CallLog) {
t0 := time.Now().UnixNano()
err, ret := client.GetTime()
log.cost = time.Now().UnixNano() - t0
log.done = err == nil
if log.done {
fnAssertTrue(t, ret > 0, "expecting ret>0")
}
}
fnTestConcurrency := func(threads int) {
logs := make([]*CallLog, threads)
for i, _ := range logs {
logs[i] = new(CallLog)
}
var g sync.WaitGroup
conn := new(net_rpc.TimeConnection)
_ = conn.Connect("localhost:3333", func(client net_rpc.ITimeClientV2) error {
for i, _ := range logs {
n := i
g.Add(1)
go func() {
fnTestRpcCall(client, logs[n])
g.Done()
}()
}
g.Wait()
return nil
})
var failed, max, avg int64 = 0, 0, 0
for _, it := range logs {
if !it.done {
failed++
}
if it.cost > max {
max = it.cost
}
avg += it.cost
}
avg = avg / int64(threads)
maxf := float64(max) / float64(time.Millisecond/time.Nanosecond)
avgf := float64(avg) / float64(time.Millisecond/time.Nanosecond)
t.Logf("threads=%d, failed=%d, max=%fms, avg=%fms", threads, failed, maxf, avgf)
}
fnTestConcurrency(100)
fnTestConcurrency(300)
fnTestConcurrency(500)
fnTestConcurrency(1000)
fnTestConcurrency(10000)
fnTestConcurrency(50000)
}
测试输出
比Day 1的短连接模式快一个数量级
$ go test -v *.go -test.run Test_NetRPC_V2
=== RUN Test_NetRPC_V2
2021/03/25 13:51:55 rpc.Register: method "Serve" has 2 input parameters; needs exactly three
net_rpc_v2_test.go:71: threads=100, failed=0, max=1.715795ms, avg=1.179659ms
net_rpc_v2_test.go:71: threads=300, failed=0, max=6.225059ms, avg=4.792163ms
net_rpc_v2_test.go:71: threads=500, failed=0, max=10.110459ms, avg=5.502403ms
net_rpc_v2_test.go:71: threads=1000, failed=0, max=17.945680ms, avg=8.392062ms
net_rpc_v2_test.go:71: threads=10000, failed=0, max=153.765575ms, avg=85.053883ms
net_rpc_v2_test.go:71: threads=50000, failed=0, max=709.802299ms, avg=299.928400ms
--- PASS: Test_NetRPC_V2 (1.02s)
PASS
ok command-line-arguments 1.031s
TimeConnection.go
- 封装rpc.dial以提供长连接的rpc.Client句柄。
- rpc.Client.Call方法是并发安全的， 因此允许我们使用共享的长连接。
package net_rpc
import "net/rpc"
type TimeConnection int
func (me *TimeConnection) Connect(serverAddress string, action func(client ITimeClientV2) error) error {
conn, err := rpc.Dial("tcp", serverAddress)
if err != nil {
return err
}
defer conn.Close()
return action(newTimeClientV2(conn))
}
ITimeClientV2
时间客户端接口
package net_rpc
type ITimeClientV2 interface {
GetTime() (error, int64)
}tTimeClientV2.go
持有长连接的rpc.Client指针，进行远程GetTime调用
package net_rpc
import "net/rpc"
type tTimeClientV2 struct {
client *rpc.Client
}
func newTimeClientV2(client *rpc.Client) ITimeClientV2 {
return &tTimeClientV2{ client, }
}
func (me *tTimeClientV2) GetTime() (error, int64) {
var t int64 = 0
err := me.client.Call("TimeServer.GetTime", 1, &t)
if err != nil {
return err, 0
}
return nil, t
}(end)
