整合服务降级用户

go.mod

@@ -3,6 +3,7 @@ module service.gomicro.test
 go 1.16
 
 require (
+	github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5 // indirect
 	github.com/go-kit/kit v0.12.0
 	github.com/google/uuid v1.1.2
 	github.com/gorilla/mux v1.8.0

go.sum

@@ -41,6 +41,7 @@ github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAE
 github.com/Shopify/sarama v1.19.0/go.mod h1:FVkBWblsNy7DGZRfXLU0O9RCGt5g3g3yEuWXgklEdEo=
 github.com/Shopify/toxiproxy v2.1.4+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
 github.com/VividCortex/gohistogram v1.0.0/go.mod h1:Pf5mBqqDxYaXu3hDrrU+w6nw50o/4+TcAqDqk/vUH7g=
+github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5 h1:rFw4nCn9iMW+Vajsk51NtYIcwSTkXr+JGrMd36kTDJw=
 github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5/go.mod h1:SkGFH1ia65gfNATL8TAiHDNxPzPdmEL5uirI2Uyuz6c=
 github.com/ajstarks/svgo v0.0.0-20180226025133-644b8db467af/go.mod h1:K08gAheRH3/J6wwsYMMT4xOr94bZjxIelGM0+d/wbFw=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=

hystrixtest.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"fmt"
+	"github.com/afex/hystrix-go/hystrix"
+	"math/rand"
+	"sync"
+	"time"
+)
+
+type Product struct {
+	ID    int
+	Title string
+	Price int
+}
+
+func getProduct() (Product, error) {
+	r := rand.Intn(10)
+	if r < 6 { //模拟api卡顿和超时效果
+		time.Sleep(time.Second * 4)
+	}
+	return Product{
+		ID:    101,
+		Title: "Golang从入门到精通",
+		Price: 12,
+	}, nil
+}
+
+func RecProduct() (Product, error) {
+	return Product{
+		ID:    999,
+		Title: "推荐商品",
+		Price: 120,
+	}, nil
+
+}
+
+func main() {
+
+	rand.Seed(time.Now().UnixNano())
+	configA := hystrix.CommandConfig{ //创建一个hystrix的config
+		Timeout:               3000, //command运行超过3秒就会报超时错误
+		MaxConcurrentRequests: 5,    //控制最大并发数为5，如果超过5会调用我们传入的回调函数降级
+		RequestVolumeThreshold: 5,  // 在一个统计窗口没处理的请求量达到阈值，才会进行熔断与否的判断
+		ErrorPercentThreshold: 20, //  在一个 %20的处理失败 处理熔断服务
+		SleepWindow: int(time.Second * 10), // 熔断后多久尝试是否恢复
+	}
+	hystrix.ConfigureCommand("get_prod", configA) //hystrix绑定command
+	c,_,_:=hystrix.GetCircuit("get_prod") // 熔断指针 ，bool表示是否能取到 error
+	resultChan := make(chan Product, 1)
+
+	wg := sync.WaitGroup{}
+
+	for i := 0; i < 20; i++ {
+		go (func() {
+			wg.Add(1)
+			defer wg.Done()
+			// Go为异步
+			errs := hystrix.Do("get_prod", func() error { //使用hystrix来讲我们的操作封装成command,hystrix返回值是一个chan error
+				p, _ := getProduct() //这里会随机延迟0-4秒
+				resultChan <- p
+				return nil //这里返回的error在回调中可以获取到，也就是下面的e变量
+			}, func(e error) error {
+				fmt.Println(e)
+				rcp, err := RecProduct() //推荐商品,如果这里的err不是nil,那么就会忘errs中写入这个err，下面的select就可以监控到
+				resultChan <- rcp
+				return err
+			})
+			if errs!=nil {
+				fmt.Println(errs)
+			}else {
+				select {
+				case getProd := <-resultChan:
+					fmt.Println(getProd)
+				}
+			}
+
+			fmt.Println(c.IsOpen())
+			fmt.Println(c.AllowRequest())
+		})()
+
+	}
+	wg.Wait()
+
+	time.Sleep(time.Second * 1)
+}

product2.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"github.com/afex/hystrix-go/hystrix"
+	"log"
+	"service.gomicro.test/util"
+	"time"
+)
+
+
+
+func main() {
+	configA := hystrix.CommandConfig{
+		Timeout:                2000,
+		MaxConcurrentRequests:  5,
+		RequestVolumeThreshold: 3,
+		SleepWindow:            int(time.Second * 10),
+		ErrorPercentThreshold:  20,
+	}
+
+	hystrix.ConfigureCommand("getuser", configA)
+	err := hystrix.Do("getuser", func() error {
+		res, err := util.GetUser() //调用方法
+		fmt.Println(res)
+		return err
+	}, func(e error) error {
+		fmt.Println("降级用户")
+		return e
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+}

util/UserUtil.go

@@ -0,0 +1,67 @@
+package util
+
+import (
+	"context"
+	"fmt"
+	"github.com/go-kit/kit/endpoint"
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/sd"
+	"github.com/go-kit/kit/sd/consul"
+	"github.com/go-kit/kit/sd/lb"
+	httptransport "github.com/go-kit/kit/transport/http"
+	consulapi "github.com/hashicorp/consul/api"
+	"io"
+	"net/url"
+	"os"
+	"service.gomicro.test/DirectServices"
+	"time"
+)
+
+func GetUser() (string, error) {
+	//第一步创建client
+	{
+		config := consulapi.DefaultConfig()            //初始化consul的配置
+		config.Address = "localhost:8500"              //consul的地址
+		api_client, err := consulapi.NewClient(config) //根据consul的配置初始化client
+		if err != nil {
+			return "", err
+		}
+		client := consul.NewClient(api_client) //根据client创建实例
+
+		var logger log.Logger
+		{
+			logger = log.NewLogfmtLogger(os.Stdout)
+			var Tag = []string{"primary"}
+			instancer := consul.NewInstancer(client, logger, "userservice", Tag, true) //最后的true表示只有通过健康检查的服务才能被得到
+			{
+				factory := func(service_url string) (endpoint.Endpoint, io.Closer, error) { //factory定义了如何获得服务端的endpoint,这里的service_url是从consul中读取到的service的address我这里是192.168.3.14:8000
+					tart, _ := url.Parse("http://" + service_url)                                                                                 //server ip +8080真实服务的地址
+					return httptransport.NewClient("GET", tart, DirectServices.GetUserInfoRequest, DirectServices.GetUserInfoResponse).Endpoint(), nil, nil //我再GetUserInfo_Request里面定义了访问哪一个api把url拼接成了http://192.168.3.14:8000/v1/user/{uid}的形式
+				}
+				endpointer := sd.NewEndpointer(instancer, factory, logger)
+				endpoints, err := endpointer.Endpoints() //获取所有的服务端当前server的所有endpoint函数
+				if err != nil {
+					return "", err
+				}
+				fmt.Println("服务有", len(endpoints), "条")
+
+				mylb := lb.NewRandom(endpointer, time.Now().UnixNano()) //使用go-kit自带的轮询
+
+				for {
+					getUserInfo, err := mylb.Endpoint() //写死获取第一个
+					ctx := context.Background()         //第三步：创建一个context上下文对象
+
+					//第四步：执行
+					res, err := getUserInfo(ctx, DirectServices.UserRequest{Uid: 101})
+					if err != nil {
+						return "", err
+					}
+					//第五步：断言，得到响应值
+					userinfo := res.(DirectServices.UserResponse)
+					return userinfo.Result, nil
+				}
+
+			}
+		}
+	}
+}