| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package servicediscovery |
| |
| import ( |
| "bytes" |
| "encoding/json" |
| "strconv" |
| "strings" |
| "sync" |
| ) |
| |
| import ( |
| gxset "github.com/dubbogo/gost/container/set" |
| perrors "github.com/pkg/errors" |
| "go.uber.org/atomic" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-go/common" |
| "github.com/apache/dubbo-go/common/constant" |
| "github.com/apache/dubbo-go/common/extension" |
| "github.com/apache/dubbo-go/common/logger" |
| "github.com/apache/dubbo-go/common/observer" |
| "github.com/apache/dubbo-go/config" |
| "github.com/apache/dubbo-go/metadata/mapping" |
| "github.com/apache/dubbo-go/metadata/service" |
| "github.com/apache/dubbo-go/metadata/service/exporter/configurable" |
| "github.com/apache/dubbo-go/registry" |
| "github.com/apache/dubbo-go/registry/event" |
| "github.com/apache/dubbo-go/registry/servicediscovery/synthesizer" |
| "github.com/apache/dubbo-go/remoting" |
| ) |
| |
| const ( |
| protocolName = "service-discovery" |
| ) |
| |
| func init() { |
| extension.SetRegistry(protocolName, newServiceDiscoveryRegistry) |
| } |
| |
| // serviceDiscoveryRegistry is the implementation of application-level registry. |
| // It's completely different from other registry implementations |
| // This implementation is based on ServiceDiscovery abstraction and ServiceNameMapping |
| // In order to keep compatible with interface-level registry, |
| // this implementation is |
| type serviceDiscoveryRegistry struct { |
| lock sync.RWMutex |
| url *common.URL |
| serviceDiscovery registry.ServiceDiscovery |
| subscribedServices *gxset.HashSet |
| serviceNameMapping mapping.ServiceNameMapping |
| metaDataService service.MetadataService |
| registeredListeners *gxset.HashSet |
| subscribedURLsSynthesizers []synthesizer.SubscribedURLsSynthesizer |
| serviceRevisionExportedURLsCache map[string]map[string][]*common.URL |
| } |
| |
| func newServiceDiscoveryRegistry(url *common.URL) (registry.Registry, error) { |
| |
| tryInitMetadataService(url) |
| |
| serviceDiscovery, err := creatServiceDiscovery(url) |
| if err != nil { |
| return nil, err |
| } |
| subscribedServices := parseServices(url.GetParam(constant.SUBSCRIBED_SERVICE_NAMES_KEY, "")) |
| subscribedURLsSynthesizers := synthesizer.GetAllSynthesizer() |
| serviceNameMapping := extension.GetGlobalServiceNameMapping() |
| metaDataService, err := extension.GetMetadataService(config.GetApplicationConfig().MetadataType) |
| if err != nil { |
| return nil, perrors.WithMessage(err, "could not init metadata service") |
| } |
| return &serviceDiscoveryRegistry{ |
| url: url, |
| serviceDiscovery: serviceDiscovery, |
| subscribedServices: subscribedServices, |
| subscribedURLsSynthesizers: subscribedURLsSynthesizers, |
| registeredListeners: gxset.NewSet(), |
| serviceRevisionExportedURLsCache: make(map[string]map[string][]*common.URL, 8), |
| serviceNameMapping: serviceNameMapping, |
| metaDataService: metaDataService, |
| }, nil |
| } |
| |
| func (s *serviceDiscoveryRegistry) UnRegister(url *common.URL) error { |
| if !shouldRegister(url) { |
| return nil |
| } |
| return s.metaDataService.UnexportURL(url) |
| } |
| |
| func (s *serviceDiscoveryRegistry) UnSubscribe(url *common.URL, listener registry.NotifyListener) error { |
| if !shouldSubscribe(url) { |
| return nil |
| } |
| return s.metaDataService.UnsubscribeURL(url) |
| } |
| |
| func creatServiceDiscovery(url *common.URL) (registry.ServiceDiscovery, error) { |
| sdcName := url.GetParam(constant.SERVICE_DISCOVERY_KEY, "") |
| sdc, ok := config.GetBaseConfig().GetServiceDiscoveries(sdcName) |
| if !ok { |
| return nil, perrors.Errorf("The service discovery with name: %s is not found", sdcName) |
| } |
| originServiceDiscovery, err := extension.GetServiceDiscovery(sdc.Protocol, sdcName) |
| if err != nil { |
| return nil, perrors.WithMessage(err, "Create service discovery fialed") |
| } |
| return event.NewEventPublishingServiceDiscovery(originServiceDiscovery), nil |
| } |
| |
| func parseServices(literalServices string) *gxset.HashSet { |
| set := gxset.NewSet() |
| if len(literalServices) == 0 { |
| return set |
| } |
| var splitServices = strings.Split(literalServices, ",") |
| for _, s := range splitServices { |
| if len(s) != 0 { |
| set.Add(s) |
| } |
| } |
| return set |
| } |
| |
| func (s *serviceDiscoveryRegistry) GetServiceDiscovery() registry.ServiceDiscovery { |
| return s.serviceDiscovery |
| } |
| |
| func (s *serviceDiscoveryRegistry) GetUrl() *common.URL { |
| return s.url |
| } |
| |
| func (s *serviceDiscoveryRegistry) IsAvailable() bool { |
| // TODO(whether available depends on metadata service and service discovery) |
| return true |
| } |
| |
| func (s *serviceDiscoveryRegistry) Destroy() { |
| err := s.serviceDiscovery.Destroy() |
| if err != nil { |
| logger.Errorf("destroy serviceDiscovery catch error:%s", err.Error()) |
| } |
| } |
| |
| func (s *serviceDiscoveryRegistry) Register(url *common.URL) error { |
| if !shouldRegister(url) { |
| return nil |
| } |
| ok, err := s.metaDataService.ExportURL(url) |
| |
| if err != nil { |
| logger.Errorf("The URL[%s] registry catch error:%s!", url.String(), err.Error()) |
| return err |
| } |
| if !ok { |
| logger.Warnf("The URL[%s] has been registry!", url.String()) |
| } |
| |
| return s.serviceNameMapping.Map(url.GetParam(constant.INTERFACE_KEY, ""), |
| url.GetParam(constant.GROUP_KEY, ""), |
| url.GetParam(constant.Version, ""), |
| url.Protocol) |
| } |
| |
| func shouldRegister(url *common.URL) bool { |
| side := url.GetParam(constant.SIDE_KEY, "") |
| if side == constant.PROVIDER_PROTOCOL { |
| return true |
| } |
| logger.Debugf("The URL should not be register.", url.String()) |
| return false |
| } |
| |
| func (s *serviceDiscoveryRegistry) Subscribe(url *common.URL, notify registry.NotifyListener) error { |
| if !shouldSubscribe(url) { |
| return nil |
| } |
| _, err := s.metaDataService.SubscribeURL(url) |
| if err != nil { |
| return perrors.WithMessage(err, "subscribe url error: "+url.String()) |
| } |
| services := s.getServices(url) |
| if services.Empty() { |
| return perrors.Errorf("Should has at least one way to know which services this interface belongs to, "+ |
| "subscription url:%s", url.String()) |
| } |
| for _, srv := range services.Values() { |
| serviceName := srv.(string) |
| serviceInstances := s.serviceDiscovery.GetInstances(serviceName) |
| s.subscribe(url, notify, serviceName, serviceInstances) |
| listener := ®istry.ServiceInstancesChangedListener{ |
| ServiceName: serviceName, |
| ChangedNotify: &InstanceChangeNotify{ |
| notify: notify, |
| serviceDiscoveryRegistry: s, |
| }, |
| } |
| s.registerServiceInstancesChangedListener(url, listener) |
| } |
| return nil |
| } |
| |
| func (s *serviceDiscoveryRegistry) registerServiceInstancesChangedListener(url *common.URL, listener *registry.ServiceInstancesChangedListener) { |
| listenerId := listener.ServiceName + ":" + getUrlKey(url) |
| if !s.subscribedServices.Contains(listenerId) { |
| err := s.serviceDiscovery.AddListener(listener) |
| if err != nil { |
| logger.Errorf("add listener[%s] catch error,url:%s err:%s", listenerId, url.String(), err.Error()) |
| } |
| } |
| |
| } |
| |
| func getUrlKey(url *common.URL) string { |
| var bf bytes.Buffer |
| if len(url.Protocol) != 0 { |
| bf.WriteString(url.Protocol) |
| bf.WriteString("://") |
| } |
| if len(url.Location) != 0 { |
| bf.WriteString(url.Location) |
| bf.WriteString(":") |
| bf.WriteString(url.Port) |
| } |
| if len(url.Path) != 0 { |
| bf.WriteString("/") |
| bf.WriteString(url.Path) |
| } |
| bf.WriteString("?") |
| appendParam(bf, constant.VERSION_KEY, url) |
| appendParam(bf, constant.GROUP_KEY, url) |
| appendParam(bf, constant.NACOS_PROTOCOL_KEY, url) |
| return bf.String() |
| } |
| |
| func appendParam(buffer bytes.Buffer, paramKey string, url *common.URL) { |
| buffer.WriteString(paramKey) |
| buffer.WriteString("=") |
| buffer.WriteString(url.GetParam(paramKey, "")) |
| } |
| |
| func (s *serviceDiscoveryRegistry) subscribe(url *common.URL, notify registry.NotifyListener, |
| serviceName string, serviceInstances []registry.ServiceInstance) { |
| if len(serviceInstances) == 0 { |
| logger.Warnf("here is no instance in service[name : %s]", serviceName) |
| return |
| } |
| var subscribedURLs []*common.URL |
| subscribedURLs = append(subscribedURLs, s.getExportedUrls(url, serviceInstances)...) |
| if len(subscribedURLs) == 0 { |
| subscribedURLs = s.synthesizeSubscribedURLs(url, serviceInstances) |
| } |
| for _, url := range subscribedURLs { |
| notify.Notify(®istry.ServiceEvent{ |
| Action: remoting.EventTypeAdd, |
| Service: url, |
| }) |
| } |
| |
| } |
| |
| func (s *serviceDiscoveryRegistry) synthesizeSubscribedURLs(subscribedURL *common.URL, serviceInstances []registry.ServiceInstance) []*common.URL { |
| var urls []*common.URL |
| for _, syn := range s.subscribedURLsSynthesizers { |
| if syn.Support(subscribedURL) { |
| urls = append(urls, syn.Synthesize(subscribedURL, serviceInstances)...) |
| } |
| } |
| return urls |
| } |
| |
| func shouldSubscribe(url *common.URL) bool { |
| return !shouldRegister(url) |
| } |
| |
| func (s *serviceDiscoveryRegistry) getServices(url *common.URL) *gxset.HashSet { |
| services := gxset.NewSet() |
| serviceNames := url.GetParam(constant.PROVIDER_BY, "") |
| if len(serviceNames) > 0 { |
| services = parseServices(serviceNames) |
| } |
| if services.Empty() { |
| services = s.findMappedServices(url) |
| if services.Empty() { |
| return s.subscribedServices |
| } |
| } |
| return services |
| } |
| |
| func (s *serviceDiscoveryRegistry) findMappedServices(url *common.URL) *gxset.HashSet { |
| serviceInterface := url.GetParam(constant.INTERFACE_KEY, url.Path) |
| group := url.GetParam(constant.GROUP_KEY, "") |
| version := url.GetParam(constant.VERSION_KEY, "") |
| protocol := url.Protocol |
| serviceNames, err := s.serviceNameMapping.Get(serviceInterface, group, version, protocol) |
| if err != nil { |
| logger.Errorf("get serviceInterface:[%s] group:[%s] version:[%s] protocol:[%s] from "+ |
| "serviceNameMap error:%s", err.Error()) |
| return gxset.NewSet() |
| } |
| return serviceNames |
| } |
| |
| func (s *serviceDiscoveryRegistry) getExportedUrls(subscribedURL *common.URL, serviceInstances []registry.ServiceInstance) []*common.URL { |
| var filterInstances []registry.ServiceInstance |
| for _, s := range serviceInstances { |
| if !s.IsEnable() || !s.IsHealthy() { |
| continue |
| } |
| metaData := s.GetMetadata() |
| _, ok1 := metaData[constant.METADATA_SERVICE_URL_PARAMS_PROPERTY_NAME] |
| _, ok2 := metaData[constant.METADATA_SERVICE_URLS_PROPERTY_NAME] |
| if !ok1 && !ok2 { |
| continue |
| } |
| filterInstances = append(filterInstances, s) |
| } |
| if len(filterInstances) == 0 { |
| return []*common.URL{} |
| } |
| s.prepareServiceRevisionExportedURLs(filterInstances) |
| subscribedURLs := s.cloneExportedURLs(subscribedURL, filterInstances) |
| return subscribedURLs |
| } |
| |
| func (s *serviceDiscoveryRegistry) getExportedUrlsByInst(serviceInstance registry.ServiceInstance) []*common.URL { |
| var urls []*common.URL |
| metadataStorageType := getExportedStoreType(serviceInstance) |
| proxyFactory := extension.GetMetadataServiceProxyFactory(metadataStorageType) |
| if proxyFactory == nil { |
| return urls |
| } |
| metadataService := proxyFactory.GetProxy(serviceInstance) |
| if metadataService == nil { |
| return urls |
| } |
| result, err := metadataService.GetExportedURLs(constant.ANY_VALUE, constant.ANY_VALUE, constant.ANY_VALUE, constant.ANY_VALUE) |
| if err != nil { |
| logger.Errorf("get exported urls catch error:%s,instance:%+v", err.Error(), serviceInstance) |
| return urls |
| } |
| |
| ret := make([]*common.URL, 0, len(result)) |
| for _, ui := range result { |
| |
| u, err := common.NewURL(ui.(string)) |
| |
| if err != nil { |
| logger.Errorf("could not parse the url string to URL structure: %s", ui.(string), err) |
| continue |
| } |
| ret = append(ret, u) |
| } |
| return ret |
| } |
| |
| func (s *serviceDiscoveryRegistry) prepareServiceRevisionExportedURLs(serviceInstances []registry.ServiceInstance) { |
| s.lock.Lock() |
| // 1. expunge stale |
| s.expungeStaleRevisionExportedURLs(serviceInstances) |
| // 2. Initialize |
| s.initRevisionExportedURLs(serviceInstances) |
| s.lock.Unlock() |
| } |
| |
| func (s *serviceDiscoveryRegistry) expungeStaleRevisionExportedURLs(serviceInstances []registry.ServiceInstance) { |
| serviceName := serviceInstances[0].GetServiceName() |
| revisionExportedURLsMap, exist := s.serviceRevisionExportedURLsCache[serviceName] |
| if !exist { |
| return |
| } |
| existRevision := gxset.NewSet() |
| for k := range revisionExportedURLsMap { |
| existRevision.Add(k) |
| } |
| currentRevision := gxset.NewSet() |
| for _, s := range serviceInstances { |
| rv := getExportedServicesRevision(s) |
| if len(rv) != 0 { |
| currentRevision.Add(rv) |
| } |
| } |
| // staleRevisions = existedRevisions(copy) - currentRevisions |
| staleRevision := gxset.NewSet(existRevision.Values()...) |
| staleRevision.Remove(currentRevision.Values()...) |
| // remove exported URLs if staled |
| for _, s := range staleRevision.Values() { |
| delete(revisionExportedURLsMap, s.(string)) |
| } |
| } |
| |
| func (s *serviceDiscoveryRegistry) initRevisionExportedURLs(serviceInstances []registry.ServiceInstance) { |
| // initialize the revision exported URLs that the selected service instance exported |
| s.initSelectedRevisionExportedURLs(serviceInstances) |
| // initialize the revision exported URLs that other service instances exported |
| for _, serviceInstance := range serviceInstances { |
| s.initRevisionExportedURLsByInst(serviceInstance) |
| } |
| } |
| |
| func (s *serviceDiscoveryRegistry) initSelectedRevisionExportedURLs(serviceInstances []registry.ServiceInstance) { |
| for range serviceInstances { |
| selectServiceInstance := s.selectServiceInstance(serviceInstances) |
| revisionExportedURLs := s.initRevisionExportedURLsByInst(selectServiceInstance) |
| if len(revisionExportedURLs) > 0 { |
| // If the result is valid,break |
| break |
| } |
| } |
| } |
| |
| func (s *serviceDiscoveryRegistry) selectServiceInstance(serviceInstances []registry.ServiceInstance) registry.ServiceInstance { |
| size := len(serviceInstances) |
| if size == 0 { |
| return nil |
| } |
| if size == 1 { |
| return serviceInstances[0] |
| } |
| selectorName := s.url.GetParam(constant.SERVICE_INSTANCE_SELECTOR, "random") |
| selector, err := extension.GetServiceInstanceSelector(selectorName) |
| if err != nil { |
| logger.Errorf("get service instance selector cathe error:%s", err.Error()) |
| return nil |
| } |
| return selector.Select(s.url, serviceInstances) |
| } |
| |
| func (s *serviceDiscoveryRegistry) initRevisionExportedURLsByInst(serviceInstance registry.ServiceInstance) []*common.URL { |
| if serviceInstance == nil { |
| return nil |
| } |
| serviceName := serviceInstance.GetServiceName() |
| revision := getExportedServicesRevision(serviceInstance) |
| revisionExportedURLsMap := s.serviceRevisionExportedURLsCache[serviceName] |
| if revisionExportedURLsMap == nil { |
| revisionExportedURLsMap = make(map[string][]*common.URL, 4) |
| s.serviceRevisionExportedURLsCache[serviceName] = revisionExportedURLsMap |
| } |
| revisionExportedURLs := revisionExportedURLsMap[revision] |
| firstGet := false |
| if len(revisionExportedURLs) == 0 { |
| if len(revisionExportedURLsMap) > 0 { |
| // The case is that current ServiceInstance with the different revision |
| logger.Warnf("The ServiceInstance[id: %s, host : %s , port : %s] has different revision : %s"+ |
| ", please make sure the service [name : %s] is changing or not.", serviceInstance.GetId(), |
| serviceInstance.GetHost(), serviceInstance.GetPort(), revision, serviceInstance.GetServiceName()) |
| } else { |
| firstGet = true |
| } |
| revisionExportedURLs = s.getExportedUrlsByInst(serviceInstance) |
| if revisionExportedURLs != nil { |
| revisionExportedURLsMap[revision] = revisionExportedURLs |
| logger.Debugf("Get the exported URLs[size : %s, first : %s] from the target service "+ |
| "instance [id: %s , service : %s , host : %s , port : %s , revision : %s]", |
| len(revisionExportedURLs), firstGet, serviceInstance.GetId(), serviceInstance.GetServiceName(), |
| serviceInstance.GetHost(), serviceInstance.GetPort(), revision) |
| } |
| } else { |
| // Else, The cache is hit |
| logger.Debugf("Get the exported URLs[size : %s] from cache, the instance"+ |
| "[id: %s , service : %s , host : %s , port : %s , revision : %s]", len(revisionExportedURLs), firstGet, |
| serviceInstance.GetId(), serviceInstance.GetServiceName(), serviceInstance.GetHost(), |
| serviceInstance.GetPort(), revision) |
| } |
| return revisionExportedURLs |
| } |
| |
| func getExportedServicesRevision(serviceInstance registry.ServiceInstance) string { |
| metaData := serviceInstance.GetMetadata() |
| return metaData[constant.EXPORTED_SERVICES_REVISION_PROPERTY_NAME] |
| } |
| |
| func getExportedStoreType(serviceInstance registry.ServiceInstance) string { |
| metaData := serviceInstance.GetMetadata() |
| result, ok := metaData[constant.METADATA_STORAGE_TYPE_PROPERTY_NAME] |
| if !ok { |
| return constant.DEFAULT_METADATA_STORAGE_TYPE |
| } |
| return result |
| } |
| |
| func (s *serviceDiscoveryRegistry) cloneExportedURLs(url *common.URL, serviceInsances []registry.ServiceInstance) []*common.URL { |
| if len(serviceInsances) == 0 { |
| return []*common.URL{} |
| } |
| var clonedExportedURLs []*common.URL |
| removeParamSet := gxset.NewSet() |
| removeParamSet.Add(constant.PID_KEY) |
| removeParamSet.Add(constant.TIMESTAMP_KEY) |
| for _, serviceInstance := range serviceInsances { |
| templateExportURLs := s.getTemplateExportedURLs(url, serviceInstance) |
| host := serviceInstance.GetHost() |
| for _, u := range templateExportURLs { |
| port := strconv.Itoa(getProtocolPort(serviceInstance, u.Protocol)) |
| if u.Location != host || u.Port != port { |
| u.Port = port // reset port |
| u.Location = host + ":" + port // reset host |
| } |
| |
| cloneUrl := u.CloneExceptParams(removeParamSet) |
| clonedExportedURLs = append(clonedExportedURLs, cloneUrl) |
| } |
| } |
| return clonedExportedURLs |
| |
| } |
| |
| type endpoint struct { |
| Port int `json:"port,omitempty"` |
| Protocol string `json:"protocol,omitempty"` |
| } |
| |
| func getProtocolPort(serviceInstance registry.ServiceInstance, protocol string) int { |
| md := serviceInstance.GetMetadata() |
| rawEndpoints := md[constant.SERVICE_INSTANCE_ENDPOINTS] |
| if len(rawEndpoints) == 0 { |
| return -1 |
| } |
| var endpoints []endpoint |
| err := json.Unmarshal([]byte(rawEndpoints), &endpoints) |
| if err != nil { |
| logger.Errorf("json umarshal rawEndpoints[%s] catch error:%s", rawEndpoints, err.Error()) |
| return -1 |
| } |
| for _, e := range endpoints { |
| if e.Protocol == protocol { |
| return e.Port |
| } |
| } |
| return -1 |
| } |
| func (s *serviceDiscoveryRegistry) getTemplateExportedURLs(url *common.URL, serviceInstance registry.ServiceInstance) []*common.URL { |
| exportedURLs := s.getRevisionExportedURLs(serviceInstance) |
| if len(exportedURLs) == 0 { |
| return []*common.URL{} |
| } |
| return filterSubscribedURLs(url, exportedURLs) |
| } |
| |
| func (s *serviceDiscoveryRegistry) getRevisionExportedURLs(serviceInstance registry.ServiceInstance) []*common.URL { |
| if serviceInstance == nil { |
| return []*common.URL{} |
| } |
| serviceName := serviceInstance.GetServiceName() |
| revision := getExportedServicesRevision(serviceInstance) |
| s.lock.RLock() |
| revisionExportedURLsMap, exist := s.serviceRevisionExportedURLsCache[serviceName] |
| if !exist { |
| return []*common.URL{} |
| } |
| exportedURLs, exist := revisionExportedURLsMap[revision] |
| if !exist { |
| return []*common.URL{} |
| } |
| s.lock.RUnlock() |
| // Get a copy from source in order to prevent the caller trying to change the cached data |
| cloneExportedURLs := make([]*common.URL, len(exportedURLs)) |
| copy(cloneExportedURLs, exportedURLs) |
| return cloneExportedURLs |
| } |
| |
| func filterSubscribedURLs(subscribedURL *common.URL, exportedURLs []*common.URL) []*common.URL { |
| var filterExportedURLs []*common.URL |
| for _, url := range exportedURLs { |
| if url.GetParam(constant.INTERFACE_KEY, url.Path) != subscribedURL.GetParam(constant.INTERFACE_KEY, url.Path) { |
| break |
| } |
| if url.GetParam(constant.VERSION_KEY, "") != subscribedURL.GetParam(constant.VERSION_KEY, "") { |
| break |
| } |
| if url.GetParam(constant.GROUP_KEY, "") != subscribedURL.GetParam(constant.GROUP_KEY, "") { |
| break |
| } |
| if len(subscribedURL.Protocol) != 0 { |
| if subscribedURL.Protocol != url.Protocol { |
| break |
| } |
| } |
| filterExportedURLs = append(filterExportedURLs, url) |
| } |
| return filterExportedURLs |
| } |
| |
| type InstanceChangeNotify struct { |
| notify registry.NotifyListener |
| serviceDiscoveryRegistry *serviceDiscoveryRegistry |
| } |
| |
| func (icn *InstanceChangeNotify) Notify(event observer.Event) { |
| |
| if se, ok := event.(*registry.ServiceInstancesChangedEvent); ok { |
| sdr := icn.serviceDiscoveryRegistry |
| sdr.subscribe(sdr.url.SubURL, icn.notify, se.ServiceName, se.Instances) |
| } |
| } |
| |
| var ( |
| exporting = &atomic.Bool{} |
| ) |
| |
| // tryInitMetadataService will try to initialize metadata service |
| // TODO (move to somewhere) |
| func tryInitMetadataService(url *common.URL) { |
| |
| ms, err := extension.GetMetadataService(config.GetApplicationConfig().MetadataType) |
| if err != nil { |
| logger.Errorf("could not init metadata service", err) |
| } |
| |
| if !config.IsProvider() || exporting.Load() { |
| return |
| } |
| |
| // In theory, we can use sync.Once |
| // But sync.Once is not reentrant. |
| // Now the invocation chain is createRegistry -> tryInitMetadataService -> metadataServiceExporter.export |
| // -> createRegistry -> initMetadataService... |
| // So using sync.Once will result in dead lock |
| exporting.Store(true) |
| |
| expt := configurable.NewMetadataServiceExporter(ms) |
| |
| err = expt.Export(url) |
| if err != nil { |
| logger.Errorf("could not export the metadata service", err) |
| } |
| extension.GetGlobalDispatcher().Dispatch(event.NewServiceConfigExportedEvent(expt.(*configurable.MetadataServiceExporter).ServiceConfig)) |
| } |