热点参数限流
最后更新于：2022-04-02 02:41:09
[TOC]
### 热点参数限流
```
基于并发数控制热点参数：
{
Resource: "some-test",
MetricType: hotspot.Concurrency,
ParamIndex: 0,
Threshold: 100,
DurationInSec: 1,
},
```
基于请求数控制热点参数
```
{
Resource: "some-test",
MetricType: hotspot.QPS,
ControlBehavior: hotspot.Reject
ParamIndex: 1,
Threshold: 100,
BurstCount: 5,
DurationInSec: 1,
},
```
main.go
```
package main
import (
"fmt"
"log"
"math/rand"
"time"
sentinel "github.com/alibaba/sentinel-golang/api"
"github.com/alibaba/sentinel-golang/core/hotspot"
"github.com/alibaba/sentinel-golang/util"
)
type fooStruct struct {
n int64
}
func main() {
// We should initialize Sentinel first.
err := sentinel.InitDefault()
if err != nil {
log.Fatalf("Unexpected error: %+v", err)
}
m := make([]hotspot.SpecificValue, 1)
m[0] = hotspot.SpecificValue{
ValKind: hotspot.KindInt,
ValStr: "9",
Threshold: 0,
}
var Resource = "test"
_, err = hotspot.LoadRules([]*hotspot.Rule{
//{
// Resource: Resource,
// MetricType: hotspot.QPS,
// ControlBehavior: hotspot.Reject,
// ParamIndex: 1,
// Threshold: 50,
// MaxQueueingTimeMs: 0,
// BurstCount: 0,
// DurationInSec: 1,
// SpecificItems: m,
//},
{
Resource: Resource,
MetricType: hotspot.QPS,
ControlBehavior: hotspot.Reject,
ParamIndex: 2,
Threshold: 5,// 请求阈值
MaxQueueingTimeMs: 0,
BurstCount: 10,
DurationInSec: 1,
SpecificItems: make([]hotspot.SpecificValue, 0),
},
})
if err != nil {
log.Fatalf("Unexpected error: %+v", err)
return
}
fmt.Println("Sentinel Go hot-spot param flow control demo is running. You may see the pass/block metric in the metric log.")
for i := 0; i < 20; i++ {
go func() {
e, b := sentinel.Entry(Resource, sentinel.WithArgs(true, rand.Uint32()%30, "sentinel", fooStruct{rand.Int63() % 5}))
if b != nil {
// Blocked. We could get the block reason from the BlockError.
time.Sleep(time.Duration(rand.Uint64()%50) * time.Millisecond)
fmt.Println(util.CurrentTimeMillis(), b.Error())
} else {
// Passed, wrap the logic here.
fmt.Println(util.CurrentTimeMillis(), "passed")
time.Sleep(time.Duration(rand.Uint64()%50) * time.Millisecond)
// Be sure the entry is exited finally.
e.Exit()
}
}()
}
//for {
// e, b := sentinel.Entry(Resource, sentinel.WithArgs(false, uint32(9), "ahas", fooStruct{rand.Int63() % 5}))
// if b != nil {
// // Blocked. We could get the block reason from the BlockError.
// time.Sleep(time.Duration(rand.Uint64()%50) * time.Millisecond)
// } else {
// // Passed, wrap the logic here.
// fmt.Println(util.CurrentTimeMillis(), "passed")
// time.Sleep(time.Duration(rand.Uint64()%50) * time.Millisecond)
//
// // Be sure the entry is exited finally.
// e.Exit()
// }
//}
select{}
}
```
';