Nacos 2.1.X

注册实例

入口

com.alibaba.nacos.naming.remote.rpc.handler.InstanceRequestHandler#handle

Service service = Service.newService(request.getNamespace(), request.getGroupName(), request.getServiceName(), true);
switch (request.getType()) {
    case NamingRemoteConstants.REGISTER_INSTANCE:
        return registerInstance(service, request, meta);
}

接口流程

registerInstance(Service service, Instance instance, String clientId):

clientOperationService.registerInstance(service, request.getInstance(), meta.getConnectionId());

NotifyCenter.publishEvent(new RegisterInstanceTraceEvent());

registerInstance(Service service, Instance instance, String clientId):

//获取一个服务实例
//如果 singletonRepository 没有service 则发布 MetadataEvent.ServiceMetadataEvent 并设置到Map中
//ConcurrentHashMap<Service, Service> singletonRepository
//ConcurrentHashMap<String, Set<Service>> namespaceSingletonMaps
Service singleton = ServiceManager.getInstance().getSingleton(service);

if (!singleton.isEphemeral()) {
	//2.1.x 开始 临时实例走 gRpc 持久实例还是走http
	//也就是只优化了常用的临时实例 不常用的就没有优化
	throw new NacosRuntimeException();
}
//根据 clientId 获取一个 client
//这个对象就是对应一个连接端信息 一个连接就有一个 clientId 对应有一个 client
//ConcurrentMap<String, IpPortBasedClient> clients
Client client = clientManager.getClient(clientId);
InstancePublishInfo instanceInfo = getPublishInfo(instance);
//维护 ConcurrentHashMap<Service, InstancePublishInfo> publishers
client.addServiceInstance(singleton, instanceInfo);
client.setLastUpdatedTime();
client.recalculateRevision();
//给 client 赋值

NotifyCenter.publishEvent(new ClientOperationEvent.ClientRegisterServiceEvent();
NotifyCenter.publishEvent(new MetadataEvent.InstanceMetadataEvent();

这个主流程可以看出来，其实就做了2件事就是

1. 组装各种对象 放入各种 Map 中
2. 发布各种事件

我们看下发布的事件：
RegisterInstanceTraceEvent
ServiceMetadataEvent
ClientRegisterServiceEvent
InstanceMetadataEvent

如果要分析注册 那么应该看 ClientRegisterServiceEvent 事件处理

Client 注册 事件处理

com.alibaba.nacos.naming.core.v2.index.ClientServiceIndexesManager#handleClientOperation

//ConcurrentMap<Service, Set<String>> publisherIndexes ： Set<String> By service Map
publisherIndexes.computeIfAbsent(service, key -> new ConcurrentHashSet<>());
publisherIndexes.get(service).add(clientId);
//这里发布了服务变更事件 也就是说注册已经完成了 也就是说注册其实就是写入这个Map
NotifyCenter.publishEvent(new ServiceEvent.ServiceChangedEvent(service, true));

那这些 Map 到底有什么用呢？可以梳理一下查询服务逻辑看一下是怎么关联的

服务订阅

入口

com.alibaba.nacos.naming.remote.rpc.handler.SubscribeServiceRequestHandler#handle

Service service = Service.newService(namespaceId, groupName, serviceName, true);
Subscriber subscriber = new Subscriber(meta.getClientIp(), meta.getClientVersion(), app, meta.getClientIp(),
	namespaceId, groupedServiceName, 0, request.getClusters());

// 这一句比较关键 下边详细分析
ServiceInfo serviceInfo = ServiceUtil.selectInstancesWithHealthyProtection(serviceStorage.getData(service),
	metadataManager.getServiceMetadata(service).orElse(null), subscriber.getCluster(), false,
    true, subscriber.getIp());
if (request.isSubscribe()) {
    clientOperationService.subscribeService(service, subscriber, meta.getConnectionId());
    NotifyCenter.publishEvent(new SubscribeServiceTraceEvent(System.currentTimeMillis(),
            meta.getClientIp(), service.getNamespace(), service.getGroup(), service.getName()));
}

//从这里看一看出服务列表就是在 serviceInfo 中
return new SubscribeServiceResponse(ResponseCode.SUCCESS.getCode(), "success", serviceInfo);

ServiceUtil.selectInstancesWithHealthyProtection(serviceStorage.getData(service),
	metadataManager.getServiceMetadata(service).orElse(null), subscriber.getCluster(), false,
    true, subscriber.getIp())：

serviceStorage.getData(service):
// 看下缓存有不 没有就创建一个 
return serviceDataIndexes.containsKey(service) ? serviceDataIndexes.get(service) : getPushData(service);

getPushData(service):

ServiceInfo result = emptyServiceInfo(service);
//ConcurrentHashMap<Service, Service> singletonRepository 这个有了
Service singleton = ServiceManager.getInstance().getSingleton(service);
//根据 Service 获取所有 Instances
result.setHosts(getAllInstancesFromIndex(singleton));
serviceDataIndexes.put(singleton, result);
return result;

List<Instance> getAllInstancesFromIndex(Service service):

//ConcurrentMap<Service, Set<String>> publisherIndexes 根据service获取 Set<clientId>
for (String each : serviceIndexesManager.getAllClientsRegisteredService(service)) {
	//ConcurrentMap<String, IpPortBasedClient> clients
	//ConcurrentHashMap<Service, InstancePublishInfo> publishers
	Optional<InstancePublishInfo> instancePublishInfo = getInstanceInfo(each, service);
	if (instancePublishInfo.isPresent()) {
        InstancePublishInfo publishInfo = instancePublishInfo.get();
        if (publishInfo instanceof BatchInstancePublishInfo) {
            BatchInstancePublishInfo batchInstancePublishInfo = (BatchInstancePublishInfo) publishInfo;
            List<Instance> batchInstance = parseBatchInstance(service, batchInstancePublishInfo, clusters);
            result.addAll(batchInstance);
        } else {
            Instance instance = parseInstance(service, instancePublishInfo.get());
            result.add(instance);
            clusters.add(instance.getClusterName());
        }
    }
}
//维护 ConcurrentMap<Service, Set<String>> serviceClusterIndex
serviceClusterIndex.put(service, clusters);
return new LinkedList<>(result);