Talk about BeatReactor of nacos-sdk-go

Posted Jun 26, 20202 min read

本文主要研究一下nacos-sdk-go的BeatReactor

BeatReactor

nacos-sdk-go-v0.3.2/clients/naming_client/beat_reactor.go

type BeatReactor struct {
    beatMap             cache.ConcurrentMap
    serviceProxy        NamingProxy
    clientBeatInterval  int64
    beatThreadCount     int
    beatThreadSemaphore *nsema.Semaphore
    beatRecordMap       cache.ConcurrentMap
}
  • BeatReactor定义了beatMap、serviceProxy、clientBeatInterval、beatThreadCount、beatThreadSemaphore、beatRecordMap属性

NewBeatReactor

nacos-sdk-go-v0.3.2/clients/naming_client/beat_reactor.go

func NewBeatReactor(serviceProxy NamingProxy, clientBeatInterval int64) BeatReactor {
    br := BeatReactor{}
    if clientBeatInterval <= 0 {
        clientBeatInterval = 5 * 1000
    }
    br.beatMap = cache.NewConcurrentMap()
    br.serviceProxy = serviceProxy
    br.clientBeatInterval = clientBeatInterval
    br.beatThreadCount = Default_Beat_Thread_Num
    br.beatRecordMap = cache.NewConcurrentMap()
    br.beatThreadSemaphore = nsema.NewSemaphore(br.beatThreadCount)
    return br
}
  • NewBeatReactor方法创建了BeatReactor,并初始化其属性

AddBeatInfo

nacos-sdk-go-v0.3.2/clients/naming_client/beat_reactor.go

func(br *BeatReactor) AddBeatInfo(serviceName string, beatInfo model.BeatInfo) {
    log.Printf("[INFO]adding beat:<%s> to beat map.\n", utils.ToJsonString(beatInfo))
    k := buildKey(serviceName, beatInfo.Ip, beatInfo.Port)
    br.beatMap.Set(k, &beatInfo)
    go br.sendInstanceBeat(k, &beatInfo)
}
  • AddBeatInfo方法通过buildKey构建key,然后将其放进去beatMap,之后异步执行br.sendInstanceBeat

RemoveBeatInfo

nacos-sdk-go-v0.3.2/clients/naming_client/beat_reactor.go

func(br *BeatReactor) RemoveBeatInfo(serviceName string, ip string, port uint64) {
    log.Printf("[INFO]remove beat:%s@%s:%d from beat map.\n", serviceName, ip, port)
    k := buildKey(serviceName, ip, port)
    data, exist := br.beatMap.Get(k)
    if exist {
        beatInfo := data.(*model.BeatInfo)
        beatInfo.Stopped = true
    }
    br.beatMap.Remove(k)
}
  • RemoveBeatInfo方法将指定key从beatMap移除,对于已经在beatMap中的设置其Stopped为true

sendInstanceBeat

nacos-sdk-go-v0.3.2/clients/naming_client/beat_reactor.go

func(br *BeatReactor) sendInstanceBeat(k string, beatInfo *model.BeatInfo) {
    for {
        br.beatThreadSemaphore.Acquire()
        //如果当前实例注销,则进行停止心跳
        if beatInfo.Stopped {
            log.Printf("[INFO]intance[%s]stop heartBeating\n", k)
            br.beatThreadSemaphore.Release()
            return
        }

        //进行心跳通信
        beatInterval, err := br.serviceProxy.SendBeat(*beatInfo)
        if err != nil {
            log.Printf("[ERROR]:beat to server return error:%s \n", err.Error())
            br.beatThreadSemaphore.Release()
            t := time.NewTimer(beatInfo.Period)
            <-t.C
            continue
        }
        if beatInterval > 0 {
            beatInfo.Period = time.Duration(time.Millisecond.Nanoseconds() * beatInterval)
        }

        br.beatRecordMap.Set(k, utils.CurrentMillis())
        br.beatThreadSemaphore.Release()

        t := time.NewTimer(beatInfo.Period)
        <-t.C
    }
}
  • sendInstanceBeat方法先执行br.beatThreadSemaphore.Acquire(),之后通过br.serviceProxy.SendBeat(*beatInfo)来发送beat,之后执行br.beatThreadSemaphore.Release(),然后新创建time.NewTimer(beatInfo.Period)

小结

BeatReactor定义了beatMap、serviceProxy、clientBeatInterval、beatThreadCount、beatThreadSemaphore、beatRecordMap属性;它提供了NewBeatReactor、AddBeatInfo、RemoveBeatInfo方法

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