Merge pull request #384 from LibiChai/master

#206 add breaker doc

doc/wiki-cn/breaker.md

@@ -0,0 +1,49 @@
+## 熔断器/Breaker
+熔断器是为了当依赖的服务已经出现故障时，主动阻止对依赖服务的请求。保证自身服务的正常运行不受依赖服务影响，防止雪崩效应。
+
+## kratos内置breaker的组件
+一般情况下直接使用kratos的组件时都自带了熔断逻辑，并且在提供了对应的breaker配置项。
+目前在kratos内集成熔断器的组件有:
+- RPC client: pkg/net/rpc/warden/client
+- Mysql client：pkg/database/sql
+- Tidb client：pkg/database/tidb
+- Http client：pkg/net/http/blademaster
+
+## 使用说明
+```go
+ //初始化熔断器组
+ //一组熔断器公用同一个配置项，可从分组内取出单个熔断器使用。可用在比如mysql主从分离等场景。
+ brkGroup := breaker.NewGroup(&breaker.Config{}) 
+ //为每一个连接指定一个brekaker
+ //此处假设一个客户端连接对象实例为conn
+ //breakName定义熔断器名称 一般可以使用连接地址
+ breakName = conn.Addr
+ conn.breaker = brkGroup.Get(breakName)
+ 
+ //在连接发出请求前判断熔断器状态
+ if err = conn.breaker.Allow(); err != nil {
+		return
+  }
+ 
+ //连接执行成功或失败将结果告知braker
+ if(respErr != nil){
+      conn.breaker.MarkFailed()
+ }else{
+      conn.breaker.MarkSuccess()
+ }
+ 
+```
+
+## 配置说明
+```go
+type Config struct {
+	SwitchOff bool // 熔断器开关,默认关 false.
+
+	K float64  //触发熔断的错误率（K = 1 - 1/错误率）
+
+	Window  xtime.Duration //统计桶窗口时间
+	Bucket  int  //统计桶大小
+	Request int64 //触发熔断的最少请求数量（请求少于该值时不会触发熔断）
+}
+```
+

example/blademaster/middleware/auth/example_test.go

@@ -3,8 +3,8 @@ package auth_test
 import (
 	"fmt"
 
-	bm "github.com/bilibili/kratos/pkg/net/http/blademaster"
 	"github.com/bilibili/kratos/example/blademaster/middleware/auth"
+	bm "github.com/bilibili/kratos/pkg/net/http/blademaster"
 	"github.com/bilibili/kratos/pkg/net/metadata"
 )
 

pkg/naming/etcd/etcd_test.go

@@ -3,11 +3,11 @@ package etcd
 import (
 	"context"
 	"fmt"
-	"testing"
-	"time"
 	"github.com/bilibili/kratos/pkg/naming"
 	"go.etcd.io/etcd/clientv3"
 	"google.golang.org/grpc"
+	"testing"
+	"time"
 )
 
 func TestNew(t *testing.T) {

pkg/net/http/blademaster/context.go

@@ -49,7 +49,6 @@ type Context struct {
 	RoutePath string
 
 	Params Params
-
 }
 
 /************************************/
@@ -67,7 +66,6 @@ func (c *Context) Next() {
 	}
 }
 
-
 // Abort prevents pending handlers from being called. Note that this will not stop the current handler.
 // Let's say you have an authorization middleware that validates that the current request is authorized.
 // If the authorization fails (ex: the password does not match), call Abort to ensure the remaining handlers

pkg/net/netutil/breaker/README.md

@@ -11,10 +11,9 @@
 > 4. 默认配置如下所示：
     _conf = &Config{
             Window:  xtime.Duration(3 * time.Second),
-            Sleep:   xtime.Duration(100 * time.Millisecond),
             Bucket:  10,
-            Ratio:   0.5,
             Request: 100,
+            K:1.5,
     }
 
 ##### 测试

pkg/net/netutil/breaker/breaker.go

@@ -11,10 +11,6 @@ import (
 type Config struct {
 	SwitchOff bool // breaker switch,default off.
 
-	// Hystrix
-	Ratio float32
-	Sleep xtime.Duration
-
 	// Google
 	K float64
 
@@ -30,12 +26,6 @@ func (conf *Config) fix() {
 	if conf.Request == 0 {
 		conf.Request = 100
 	}
-	if conf.Ratio == 0 {
-		conf.Ratio = 0.5
-	}
-	if conf.Sleep == 0 {
-		conf.Sleep = xtime.Duration(500 * time.Millisecond)
-	}
 	if conf.Bucket == 0 {
 		conf.Bucket = 10
 	}
@@ -84,8 +74,6 @@ var (
 		Bucket:  10,
 		Request: 100,
 
-		Sleep: xtime.Duration(500 * time.Millisecond),
-		Ratio: 0.5,
 		// Percentage of failures must be lower than 33.33%
 		K: 1.5,
 

pkg/net/netutil/breaker/breaker_test.go

@@ -28,9 +28,7 @@ func TestGroup(t *testing.T) {
 	g := NewGroup(_conf)
 	c := &Config{
 		Window:    xtime.Duration(1 * time.Second),
-		Sleep:     xtime.Duration(100 * time.Millisecond),
 		Bucket:    10,
-		Ratio:     0.5,
 		Request:   100,
 		SwitchOff: !_conf.SwitchOff,
 	}
@@ -44,9 +42,7 @@ func TestInit(t *testing.T) {
 	switchOff := _conf.SwitchOff
 	c := &Config{
 		Window:    xtime.Duration(3 * time.Second),
-		Sleep:     xtime.Duration(100 * time.Millisecond),
 		Bucket:    10,
-		Ratio:     0.5,
 		Request:   100,
 		SwitchOff: !switchOff,
 	}
@@ -69,9 +65,7 @@ func TestGo(t *testing.T) {
 
 	_group.Reload(&Config{
 		Window:    xtime.Duration(3 * time.Second),
-		Sleep:     xtime.Duration(100 * time.Millisecond),
 		Bucket:    10,
-		Ratio:     0.5,
 		Request:   100,
 		SwitchOff: true,
 	})

pkg/net/netutil/breaker/example_test.go

@@ -12,9 +12,8 @@ import (
 func ExampleGroup() {
 	c := &breaker.Config{
 		Window:  xtime.Duration(3 * time.Second),
-		Sleep:   xtime.Duration(100 * time.Millisecond),
+		K:       1.5,
 		Bucket:  10,
-		Ratio:   0.5,
 		Request: 100,
 	}
 	// init default config

pkg/net/rpc/warden/exapmle_test.go

@@ -60,9 +60,8 @@ func ExampleClient() {
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
+			K:       1.5,
 			Request: 20,
 		},
 	})

pkg/net/rpc/warden/internal/benchmark/bench/client/client.go

@@ -39,10 +39,9 @@ func wardenCli() proto.HelloClient {
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
 			Request: 20,
+			K:       1.5,
 		},
 	},
 		grpc.WithInitialWindowSize(iws),

pkg/net/rpc/warden/internal/benchmark/helloworld/client/greeter_client.go

@@ -21,10 +21,9 @@ var (
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
 			Request: 20,
+			K:       1.5,
 		},
 	}
 	cli         pb.GreeterClient

pkg/net/rpc/warden/resolver/direct/test/direct_test.go

@@ -55,10 +55,9 @@ func createTestClient(t *testing.T, connStr string) pb.GreeterClient {
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
 			Request: 20,
+			K:       1.5,
 		},
 	})
 	conn, err := client.Dial(context.TODO(), connStr)

pkg/net/rpc/warden/resolver/test/resovler_test.go

@@ -74,10 +74,9 @@ func createTestClient(t *testing.T) pb.GreeterClient {
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
 			Request: 20,
+			K:       1.5,
 		},
 	})
 	conn, err := client.Dial(context.TODO(), "mockdiscovery://authority/main.test")

pkg/net/rpc/warden/server_test.go

@@ -42,10 +42,8 @@ var (
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window: xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket: 10,
-			Ratio:   0.3,
+			K:      1.5,
-			Request: 20,
 		},
 	}
 	clientConfig2 = ClientConfig{
@@ -53,10 +51,9 @@ var (
 		Timeout: xtime.Duration(time.Second * 10),
 		Breaker: &breaker.Config{
 			Window:  xtime.Duration(3 * time.Second),
-			Sleep:   xtime.Duration(3 * time.Second),
 			Bucket:  10,
-			Ratio:   0.3,
 			Request: 20,
+			K:       1.5,
 		},
 		Method: map[string]*ClientConfig{`/testproto.Greeter/SayHello`: {Timeout: xtime.Duration(time.Millisecond * 200)}},
 	}

tool/protobuf/pkg/gen/main.go

@@ -3,9 +3,9 @@ package gen
 import (
 	"io"
 	"io/ioutil"
+	"log"
 	"os"
 	"strings"
-	"log"
 
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/protoc-gen-go/descriptor"
@@ -70,7 +70,6 @@ func writeResponse(w io.Writer, resp *plugin.CodeGeneratorResponse) {
 	}
 }
 
-
 // Fail log and exit
 func Fail(msgs ...string) {
 	s := strings.Join(msgs, " ")
@@ -85,7 +84,6 @@ func Info(msgs ...string) {
 	os.Exit(1)
 }
 
-
 // Error log and exit
 func Error(err error, msgs ...string) {
 	s := strings.Join(msgs, " ") + ":" + err.Error()

tool/protobuf/pkg/utils/stringutils.go

@@ -1,4 +1,3 @@
-
 package utils
 
 import (