Create & Init Project...

library/net/netutil/breaker/BUILD

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+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_test",
+    "go_library",
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "breaker_test.go",
+        "sre_breaker_test.go",
+    ],
+    embed = [":go_default_library"],
+    rundir = ".",
+    tags = ["automanaged"],
+    deps = [
+        "//library/time:go_default_library",
+        "//vendor/github.com/stretchr/testify/assert:go_default_library",
+    ],
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "breaker.go",
+        "sre_breaker.go",
+    ],
+    importpath = "go-common/library/net/netutil/breaker",
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//library/ecode:go_default_library",
+        "//library/log:go_default_library",
+        "//library/stat/summary:go_default_library",
+        "//library/time:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_xtest",
+    srcs = ["example_test.go"],
+    tags = ["automanaged"],
+    deps = [
+        "//library/net/netutil/breaker:go_default_library",
+        "//library/time:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

library/net/netutil/breaker/CHANGELOG.md

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+#### breaker
+
+### v1.1.0
+> 1.remove hystrix and use summary.Summary instead of counter.Counter
+
+##### v1.0.3
+> 1.修复配置了conf时fix k=2
+
+##### v1.0.2
+> 1.Go支持上报普罗米修斯
+
+##### v1.0.1
+> 1. 增加Go方法
+
+##### v1.0.0
+> 1. 提供默认熔断配置，热更新配置功能
+> 2. 内敛普罗米修斯上报熔断状态功能

library/net/netutil/breaker/CONTRIBUTORS.md

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+# Author 
+zhapuyu
+liangkai
+
+# Reviewer
+maojian

library/net/netutil/breaker/OWNERS

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+# See the OWNERS docs at https://go.k8s.io/owners
+
+approvers:
+- liangkai
+- zhapuyu
+reviewers:
+- liangkai
+- maojian
+- zhapuyu

library/net/netutil/breaker/README.md

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+#### breaker
+
+##### 项目简介
+> 提供熔断器功能，供各种client（如rpc、http、msyql）等进行熔断
+> 提供Go方法供业务在breaker熔断前后进行回调处理
+
+##### 编译环境
+> 1. 请只用golang v1.8.x以上版本编译执行。
+
+##### 依赖包
+> 1. 无
+
+##### 配置说明
+> 1. NewGroup(name string,c *Config)当c==nil时则采用默认配置
+> 2. 可通过breaker.Init(c *Config)替换默认配置
+> 3. 可通过group.Reload(c *Config)进行配置更新
+> 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,
+    }
+
+##### 测试
+> 1. 执行当前目录下所有测试文件，测试所有功能

library/net/netutil/breaker/breaker.go

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+package breaker
+
+import (
+	"sync"
+	"time"
+
+	xtime "go-common/library/time"
+)
+
+// Config broker config.
+type Config struct {
+	SwitchOff bool // breaker switch,default off.
+
+	// Hystrix
+	Ratio float32
+	Sleep xtime.Duration
+
+	// Google
+	K float64
+
+	Window  xtime.Duration
+	Bucket  int
+	Request int64
+}
+
+func (conf *Config) fix() {
+	if conf.K == 0 {
+		conf.K = 1.5
+	}
+	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
+	}
+	if conf.Window == 0 {
+		conf.Window = xtime.Duration(3 * time.Second)
+	}
+}
+
+// Breaker is a CircuitBreaker pattern.
+// FIXME on int32 atomic.LoadInt32(&b.on) == _switchOn
+type Breaker interface {
+	Allow() error
+	MarkSuccess()
+	MarkFailed()
+}
+
+// Group represents a class of CircuitBreaker and forms a namespace in which
+// units of CircuitBreaker.
+type Group struct {
+	mu   sync.RWMutex
+	brks map[string]Breaker
+	conf *Config
+}
+
+const (
+	// StateOpen when circuit breaker open, request not allowed, after sleep
+	// some duration, allow one single request for testing the health, if ok
+	// then state reset to closed, if not continue the step.
+	StateOpen int32 = iota
+	// StateClosed when circuit breaker closed, request allowed, the breaker
+	// calc the succeed ratio, if request num greater request setting and
+	// ratio lower than the setting ratio, then reset state to open.
+	StateClosed
+	// StateHalfopen when circuit breaker open, after slepp some duration, allow
+	// one request, but not state closed.
+	StateHalfopen
+
+	//_switchOn int32 = iota
+	// _switchOff
+)
+
+var (
+	_mu   sync.RWMutex
+	_conf = &Config{
+		Window:  xtime.Duration(3 * time.Second),
+		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,
+
+		// Pattern: "",
+	}
+	_group = NewGroup(_conf)
+)
+
+// Init init global breaker config, also can reload config after first time call.
+func Init(conf *Config) {
+	if conf == nil {
+		return
+	}
+	_mu.Lock()
+	_conf = conf
+	_mu.Unlock()
+}
+
+// Go runs your function while tracking the breaker state of default group.
+func Go(name string, run, fallback func() error) error {
+	breaker := _group.Get(name)
+	if err := breaker.Allow(); err != nil {
+		return fallback()
+	}
+	return run()
+}
+
+// newBreaker new a breaker.
+func newBreaker(c *Config) (b Breaker) {
+	// factory
+	return newSRE(c)
+}
+
+// NewGroup new a breaker group container, if conf nil use default conf.
+func NewGroup(conf *Config) *Group {
+	if conf == nil {
+		_mu.RLock()
+		conf = _conf
+		_mu.RUnlock()
+	} else {
+		conf.fix()
+	}
+	return &Group{
+		conf: conf,
+		brks: make(map[string]Breaker),
+	}
+}
+
+// Get get a breaker by a specified key, if breaker not exists then make a new one.
+func (g *Group) Get(key string) Breaker {
+	g.mu.RLock()
+	brk, ok := g.brks[key]
+	conf := g.conf
+	g.mu.RUnlock()
+	if ok {
+		return brk
+	}
+	// NOTE here may new multi breaker for rarely case, let gc drop it.
+	brk = newBreaker(conf)
+	g.mu.Lock()
+	if _, ok = g.brks[key]; !ok {
+		g.brks[key] = brk
+	}
+	g.mu.Unlock()
+	return brk
+}
+
+// Reload reload the group by specified config, this may let all inner breaker
+// reset to a new one.
+func (g *Group) Reload(conf *Config) {
+	if conf == nil {
+		return
+	}
+	conf.fix()
+	g.mu.Lock()
+	g.conf = conf
+	g.brks = make(map[string]Breaker, len(g.brks))
+	g.mu.Unlock()
+}
+
+// Go runs your function while tracking the breaker state of group.
+func (g *Group) Go(name string, run, fallback func() error) error {
+	breaker := g.Get(name)
+	if err := breaker.Allow(); err != nil {
+		return fallback()
+	}
+	return run()
+}

library/net/netutil/breaker/breaker_test.go

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+package breaker
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	xtime "go-common/library/time"
+)
+
+func TestGroup(t *testing.T) {
+	g1 := NewGroup(nil)
+	g2 := NewGroup(_conf)
+	if g1.conf != g2.conf {
+		t.FailNow()
+	}
+
+	brk := g2.Get("key")
+	brk1 := g2.Get("key1")
+	if brk == brk1 {
+		t.FailNow()
+	}
+	brk2 := g2.Get("key")
+	if brk != brk2 {
+		t.FailNow()
+	}
+
+	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,
+	}
+	g.Reload(c)
+	if g.conf.SwitchOff == _conf.SwitchOff {
+		t.FailNow()
+	}
+}
+
+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,
+	}
+	Init(c)
+	if _conf.SwitchOff == switchOff {
+		t.FailNow()
+	}
+}
+
+func TestGo(t *testing.T) {
+	if err := Go("test_run", func() error {
+		t.Log("breaker allow,callback run()")
+		return nil
+	}, func() error {
+		t.Log("breaker not allow,callback fallback()")
+		return errors.New("breaker not allow")
+	}); err != nil {
+		t.Error(err)
+	}
+
+	_group.Reload(&Config{
+		Window:    xtime.Duration(3 * time.Second),
+		Sleep:     xtime.Duration(100 * time.Millisecond),
+		Bucket:    10,
+		Ratio:     0.5,
+		Request:   100,
+		SwitchOff: true,
+	})
+
+	if err := Go("test_fallback", func() error {
+		t.Log("breaker allow,callback run()")
+		return nil
+	}, func() error {
+		t.Log("breaker not allow,callback fallback()")
+		return nil
+	}); err != nil {
+		t.Error(err)
+	}
+}
+
+func markSuccess(b Breaker, count int) {
+	for i := 0; i < count; i++ {
+		b.MarkSuccess()
+	}
+}
+
+func markFailed(b Breaker, count int) {
+	for i := 0; i < count; i++ {
+		b.MarkFailed()
+	}
+}

library/net/netutil/breaker/example_test.go

@@ -0,0 +1,61 @@
+package breaker_test
+
+import (
+	"fmt"
+	"time"
+
+	"go-common/library/net/netutil/breaker"
+	xtime "go-common/library/time"
+)
+
+// ExampleGroup show group usage.
+func ExampleGroup() {
+	c := &breaker.Config{
+		Window:  xtime.Duration(3 * time.Second),
+		Sleep:   xtime.Duration(100 * time.Millisecond),
+		Bucket:  10,
+		Ratio:   0.5,
+		Request: 100,
+	}
+	// init default config
+	breaker.Init(c)
+	// new group
+	g := breaker.NewGroup(c)
+	// reload group config
+	c.Bucket = 100
+	c.Request = 200
+	g.Reload(c)
+	// get breaker by key
+	g.Get("key")
+}
+
+// ExampleBreaker show breaker usage.
+func ExampleBreaker() {
+	// new group,use default breaker config
+	g := breaker.NewGroup(nil)
+	brk := g.Get("key")
+	// mark request success
+	brk.MarkSuccess()
+	// mark request failed
+	brk.MarkFailed()
+	// check if breaker allow or not
+	if brk.Allow() == nil {
+		fmt.Println("breaker allow")
+	} else {
+		fmt.Println("breaker not allow")
+	}
+}
+
+// ExampleGo this example create a default group and show function callback
+// according to the state of breaker.
+func ExampleGo() {
+	run := func() error {
+		return nil
+	}
+	fallback := func() error {
+		return fmt.Errorf("unknown error")
+	}
+	if err := breaker.Go("example_go", run, fallback); err != nil {
+		fmt.Println(err)
+	}
+}

library/net/netutil/breaker/sre_breaker.go

@@ -0,0 +1,71 @@
+package breaker
+
+import (
+	"math"
+	"math/rand"
+	"sync/atomic"
+	"time"
+
+	"go-common/library/ecode"
+	"go-common/library/log"
+	"go-common/library/stat/summary"
+)
+
+// sreBreaker is a sre CircuitBreaker pattern.
+type sreBreaker struct {
+	stat summary.Summary
+
+	k       float64
+	request int64
+
+	state int32
+	r     *rand.Rand
+}
+
+func newSRE(c *Config) Breaker {
+	return &sreBreaker{
+		stat: summary.New(time.Duration(c.Window), c.Bucket),
+		r:    rand.New(rand.NewSource(time.Now().UnixNano())),
+
+		request: c.Request,
+		k:       c.K,
+		state:   StateClosed,
+	}
+}
+
+func (b *sreBreaker) Allow() error {
+	success, total := b.stat.Value()
+	k := b.k * float64(success)
+	if log.V(5) {
+		log.Info("breaker: request: %d, succee: %d, fail: %d", total, success, total-success)
+	}
+	// check overflow requests = K * success
+	if total < b.request || float64(total) < k {
+		if atomic.LoadInt32(&b.state) == StateOpen {
+			atomic.CompareAndSwapInt32(&b.state, StateOpen, StateClosed)
+		}
+		return nil
+	}
+	if atomic.LoadInt32(&b.state) == StateClosed {
+		atomic.CompareAndSwapInt32(&b.state, StateClosed, StateOpen)
+	}
+	dr := math.Max(0, (float64(total)-k)/float64(total+1))
+	rr := b.r.Float64()
+	if log.V(5) {
+		log.Info("breaker: drop ratio: %f, real rand: %f, drop: %v", dr, rr, dr > rr)
+	}
+	if dr <= rr {
+		return nil
+	}
+	return ecode.ServiceUnavailable
+}
+
+func (b *sreBreaker) MarkSuccess() {
+	b.stat.Add(1)
+}
+
+func (b *sreBreaker) MarkFailed() {
+	// NOTE: when client reject requets locally, continue add counter let the
+	// drop ratio higher.
+	b.stat.Add(0)
+}

library/net/netutil/breaker/sre_breaker_test.go

@@ -0,0 +1,59 @@
+package breaker
+
+import (
+	"testing"
+	"time"
+
+	xtime "go-common/library/time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func getSRE() Breaker {
+	return NewGroup(&Config{
+		Window:  xtime.Duration(1 * time.Second),
+		Bucket:  10,
+		Request: 100,
+		K:       2,
+	}).Get("")
+}
+
+func testSREClose(t *testing.T, b Breaker) {
+	markSuccess(b, 80)
+	assert.Equal(t, b.Allow(), nil)
+	markSuccess(b, 120)
+	assert.Equal(t, b.Allow(), nil)
+}
+
+func testSREOpen(t *testing.T, b Breaker) {
+	markSuccess(b, 100)
+	assert.Equal(t, b.Allow(), nil)
+	markFailed(b, 10000000)
+	assert.NotEqual(t, b.Allow(), nil)
+}
+
+func testSREHalfOpen(t *testing.T, b Breaker) {
+	// failback
+	assert.Equal(t, b.Allow(), nil)
+	t.Run("allow single failed", func(t *testing.T) {
+		markFailed(b, 10000000)
+		assert.NotEqual(t, b.Allow(), nil)
+	})
+	time.Sleep(2 * time.Second)
+	t.Run("allow single succeed", func(t *testing.T) {
+		assert.Equal(t, b.Allow(), nil)
+		markSuccess(b, 10000000)
+		assert.Equal(t, b.Allow(), nil)
+	})
+}
+
+func TestSRE(t *testing.T) {
+	b := getSRE()
+	testSREClose(t, b)
+
+	b = getSRE()
+	testSREOpen(t, b)
+
+	b = getSRE()
+	testSREHalfOpen(t, b)
+}