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本文主要研究一下nacos-sdk-go的NamingClient

NamingClient

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

type NamingClient struct {    nacos_client.INacosClient    hostReactor  HostReactor    serviceProxy NamingProxy    subCallback  SubscribeCallback    beatReactor  BeatReactor    indexMap     cache.ConcurrentMap}
  • NamingClient定义了hostReactor、serviceProxy、subCallback、beatReactor、indexMap属性

NewNamingClient

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

func NewNamingClient(nc nacos_client.INacosClient) (NamingClient, error) {    naming := NamingClient{}    clientConfig, err :=        nc.GetClientConfig()    if err != nil {        return naming, err    }    serverConfig, err := nc.GetServerConfig()    if err != nil {        return naming, err    }    httpAgent, err := nc.GetHttpAgent()    if err != nil {        return naming, err    }    err = logger.InitLog(clientConfig.LogDir)    if err != nil {        return naming, err    }    naming.subCallback = NewSubscribeCallback()    naming.serviceProxy, err = NewNamingProxy(clientConfig, serverConfig, httpAgent)    if err != nil {        return naming, err    }    naming.hostReactor = NewHostReactor(naming.serviceProxy, clientConfig.CacheDir+string(os.PathSeparator)+"naming",        clientConfig.UpdateThreadNum, clientConfig.NotLoadCacheAtStart, naming.subCallback, clientConfig.UpdateCacheWhenEmpty)    naming.beatReactor = NewBeatReactor(naming.serviceProxy, clientConfig.BeatInterval)    naming.indexMap = cache.NewConcurrentMap()    return naming, nil}
  • NewNamingClient方法创建NamingClient，并设置其subCallback、serviceProxy、hostReactor、beatReactor、indexMap属性

RegisterInstance

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

// 注册服务实例func (sc *NamingClient) RegisterInstance(param vo.RegisterInstanceParam) (bool, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    instance := model.Instance{        Ip:          param.Ip,        Port:        param.Port,        Metadata:    param.Metadata,        ClusterName: param.ClusterName,        Healthy:     param.Healthy,        Enable:      param.Enable,        Weight:      param.Weight,        Ephemeral:   param.Ephemeral,    }    beatInfo := model.BeatInfo{        Ip:          param.Ip,        Port:        param.Port,        Metadata:    param.Metadata,        ServiceName: utils.GetGroupName(param.ServiceName, param.GroupName),        Cluster:     param.ClusterName,        Weight:      param.Weight,        Period:      utils.GetDurationWithDefault(param.Metadata, constant.HEART_BEAT_INTERVAL, time.Second*5),    }    _, err := sc.serviceProxy.RegisterInstance(utils.GetGroupName(param.ServiceName, param.GroupName), param.GroupName, instance)    if err != nil {        return false, err    }    if instance.Ephemeral {        sc.beatReactor.AddBeatInfo(utils.GetGroupName(param.ServiceName, param.GroupName), beatInfo)    }    return true, nil}
  • RegisterInstance方法根据RegisterInstanceParam构建instance，然后通过sc.serviceProxy.RegisterInstance(utils.GetGroupName(param.ServiceName, param.GroupName), param.GroupName, instance)去注册；如果instance是Ephemeral类型的，则执行sc.beatReactor.AddBeatInfo(utils.GetGroupName(param.ServiceName, param.GroupName), beatInfo)

DeregisterInstance

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

// 注销服务实例func (sc *NamingClient) DeregisterInstance(param vo.DeregisterInstanceParam) (bool, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    sc.beatReactor.RemoveBeatInfo(utils.GetGroupName(param.ServiceName, param.GroupName), param.Ip, param.Port)    _, err := sc.serviceProxy.DeregisterInstance(utils.GetGroupName(param.ServiceName, param.GroupName), param.Ip, param.Port, param.Cluster, param.Ephemeral)    if err != nil {        return false, err    }    return true, nil}
  • DeregisterInstance方法执行sc.beatReactor.RemoveBeatInfo及sc.serviceProxy.DeregisterInstance

GetService

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

// 获取服务列表func (sc *NamingClient) GetService(param vo.GetServiceParam) (model.Service, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    service := sc.hostReactor.GetServiceInfo(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","))    return service, nil}
  • GetService方法通过sc.hostReactor.GetServiceInfo来查询service信息

GetAllServicesInfo

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

func (sc *NamingClient) GetAllServicesInfo(param vo.GetAllServiceInfoParam) ([]model.Service, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    if param.NameSpace == "" {        param.NameSpace = constant.DEFAULT_NAMESPACE_ID    }    service := sc.hostReactor.GetAllServiceInfo(param.NameSpace, param.GroupName, strings.Join(param.Clusters, ","))    return service, nil}
  • GetAllServicesInfo方法通过sc.hostReactor.GetAllServiceInfo来查询所有的service信息

SelectAllInstances

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

func (sc *NamingClient) SelectAllInstances(param vo.SelectAllInstancesParam) ([]model.Instance, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    service := sc.hostReactor.GetServiceInfo(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","))    if service.Hosts == nil || len(service.Hosts) == 0 {        return []model.Instance{}, errors.New("instance list is empty!")    }    return service.Hosts, nil}
  • SelectAllInstances方法通过sc.hostReactor.GetServiceInfo获取service信息，然后返回service.Hosts

SelectInstances

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

func (sc *NamingClient) SelectInstances(param vo.SelectInstancesParam) ([]model.Instance, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    service := sc.hostReactor.GetServiceInfo(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","))    return sc.selectInstances(service, param.HealthyOnly)}func (sc *NamingClient) selectInstances(service model.Service, healthy bool) ([]model.Instance, error) {    if service.Hosts == nil || len(service.Hosts) == 0 {        return []model.Instance{}, errors.New("instance list is empty!")    }    hosts := service.Hosts    var result []model.Instance    for _, host := range hosts {        if host.Healthy == healthy && host.Enable && host.Weight > 0 {            result = append(result, host)        }    }    return result, nil}
  • SelectInstances方法通过sc.hostReactor.GetServiceInfo获取service信息，然后再通过sc.selectInstances(service, param.HealthyOnly)获取健康的instance

SelectOneHealthyInstance

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

func (sc *NamingClient) SelectOneHealthyInstance(param vo.SelectOneHealthInstanceParam) (*model.Instance, error) {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    service := sc.hostReactor.GetServiceInfo(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","))    return sc.selectOneHealthyInstances(service)}func (sc *NamingClient) selectOneHealthyInstances(service model.Service) (*model.Instance, error) {    if service.Hosts == nil || len(service.Hosts) == 0 {        return nil, errors.New("instance list is empty!")    }    hosts := service.Hosts    var result []model.Instance    mw := 0    for _, host := range hosts {        if host.Healthy && host.Enable && host.Weight > 0 {            cw := int(math.Ceil(host.Weight))            if cw > mw {                mw = cw            }            result = append(result, host)        }    }    if len(result) == 0 {        return nil, errors.New("healthy instance list is empty!")    }    randomInstances := random(result, mw)    key := utils.GetServiceCacheKey(service.Name, service.Clusters)    i, indexOk := sc.indexMap.Get(key)    var index int    if !indexOk {        index = rand.Intn(len(randomInstances))    } else {        index = i.(int)        index += 1        if index >= len(randomInstances) {            index = index % len(randomInstances)        }    }    sc.indexMap.Set(key, index)    return &randomInstances[index], nil}
  • SelectOneHealthyInstance方法通过sc.hostReactor.GetServiceInfo获取service信息，再通过sc.selectOneHealthyInstances(service)选择一个健康的instance

Subscribe

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

// 服务监听func (sc *NamingClient) Subscribe(param *vo.SubscribeParam) error {    if param.GroupName == "" {        param.GroupName = constant.DEFAULT_GROUP    }    serviceParam := vo.GetServiceParam{        ServiceName: param.ServiceName,        GroupName:   param.GroupName,        Clusters:    param.Clusters,    }    sc.subCallback.AddCallbackFuncs(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","), &param.SubscribeCallback)    _, err := sc.GetService(serviceParam)    if err != nil {        return err    }    return nil}
  • Subscribe方法通过sc.subCallback.AddCallbackFuncs来注册callback

Unsubscribe

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

//取消服务监听func (sc *NamingClient) Unsubscribe(param *vo.SubscribeParam) error {    sc.subCallback.RemoveCallbackFuncs(utils.GetGroupName(param.ServiceName, param.GroupName), strings.Join(param.Clusters, ","), &param.SubscribeCallback)    return nil}
  • Unsubscribe方法则通过sc.subCallback.RemoveCallbackFuncs来取消callback

小结

nacos-sdk-go的NamingClient提供了RegisterInstance、DeregisterInstance、GetService、GetAllServicesInfo、SelectAllInstances、SelectInstances、SelectOneHealthyInstance、Subscribe、Unsubscribe方法

doc

  • naming_client