nacos注冊(cè)中心單節(jié)點(diǎn)ap架構(gòu)源碼解析(最新推薦)
更新時(shí)間：2023年01月03日 09:31:42 作者：bei_er
這篇文章主要介紹了nacos注冊(cè)中心單節(jié)點(diǎn)ap架構(gòu)源碼解析,本文通過示例代碼給大家介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或工作具有一定的參考借鑒價(jià)值，需要的朋友可以參考下
一、注冊(cè)流程
單nacos節(jié)點(diǎn)流程圖如下：
流程圖可以知，Nacos注冊(cè)流程包括客戶端的服務(wù)注冊(cè)、服務(wù)實(shí)例列表拉取、定時(shí)心跳任務(wù)；以及服務(wù)端的定時(shí)檢查服務(wù)實(shí)例任務(wù)、服務(wù)實(shí)例更新推送5個(gè)功能。
服務(wù)注冊(cè)：當(dāng)客戶端啟動(dòng)的時(shí)候會(huì)根據(jù)當(dāng)前微服務(wù)的配置信息把微服務(wù)注冊(cè)到nacos服務(wù)端。
服務(wù)實(shí)例列表拉取：當(dāng)客戶端啟動(dòng)的時(shí)候從nacos服務(wù)端獲取當(dāng)前服務(wù)的名稱已經(jīng)注冊(cè)的實(shí)例數(shù)據(jù)，并把這些實(shí)例數(shù)據(jù)緩存在客戶端的serviceInfoMap 對(duì)象中。
定時(shí)心跳任務(wù)：當(dāng)客戶端向nacos服務(wù)注冊(cè)臨時(shí)實(shí)例對(duì)象的時(shí)候，會(huì)創(chuàng)建一個(gè)延期的任務(wù)去往服務(wù)端發(fā)送心跳信息。如果發(fā)送心跳信息成功，則又會(huì)創(chuàng)建一個(gè)延期任務(wù)往服務(wù)端注冊(cè)心跳信息，一直重復(fù)該邏輯。nacos服務(wù)端接收到客戶端的心跳信息就是更新客戶端實(shí)例的最后心跳時(shí)間。該時(shí)間用來判斷實(shí)例是否健康和是否需要?jiǎng)h除。
定時(shí)檢查服務(wù)實(shí)例任務(wù)：nacos服務(wù)端在創(chuàng)建空服務(wù)對(duì)象的時(shí)候會(huì)通過線程池來定時(shí)執(zhí)行檢查服務(wù)，其主要邏輯為判斷當(dāng)前時(shí)間和最后心跳時(shí)間之差是否大于健康超時(shí)時(shí)間和刪除實(shí)例超時(shí)時(shí)間，如果大于，則更新實(shí)例的健康狀態(tài)和刪除當(dāng)前實(shí)例。定時(shí)執(zhí)行的規(guī)則為5秒之后執(zhí)行檢查，并且每次執(zhí)行完檢查之后，5秒之后再次執(zhí)行檢查。
服務(wù)實(shí)例更新推送：當(dāng)有客戶端更新實(shí)例對(duì)象時(shí)，服務(wù)端會(huì)先獲取該客戶端的服務(wù)名稱下所有已經(jīng)注冊(cè)的客戶端實(shí)例，并會(huì)針每一個(gè)客戶端發(fā)送一個(gè)更新serviceinfo的udp消息，客戶端監(jiān)聽收到nacos服務(wù)端發(fā)送的udp數(shù)據(jù)后進(jìn)行本地緩存的更新。
二、客戶端
一、服務(wù)注冊(cè)
根據(jù)spring-cloud-starter-alibaba-nacos-discovery的spring.factories文件,找到服務(wù)注冊(cè)啟動(dòng)配置類。
spring.factories文件內(nèi)容為如下，
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ com.alibaba.cloud.nacos.discovery.NacosDiscoveryAutoConfiguration,\ com.alibaba.cloud.nacos.ribbon.RibbonNacosAutoConfiguration,\ com.alibaba.cloud.nacos.endpoint.NacosDiscoveryEndpointAutoConfiguration,\ com.alibaba.cloud.nacos.registry.NacosServiceRegistryAutoConfiguration,\ com.alibaba.cloud.nacos.discovery.NacosDiscoveryClientConfiguration,\ com.alibaba.cloud.nacos.discovery.reactive.NacosReactiveDiscoveryClientConfiguration,\ com.alibaba.cloud.nacos.discovery.configclient.NacosConfigServerAutoConfiguration,\ com.alibaba.cloud.nacos.NacosServiceAutoConfiguration org.springframework.cloud.bootstrap.BootstrapConfiguration=\ com.alibaba.cloud.nacos.discovery.configclient.NacosDiscoveryClientConfigServiceBootstrapConfiguration
根據(jù)名稱判斷可以得出 NacosServiceRegistryAutoConfiguration 為服務(wù)注冊(cè)啟動(dòng)配置類，源碼如下
@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnNacosDiscoveryEnabled
@ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled",
matchIfMissing = true)
@AutoConfigureAfter({ AutoServiceRegistrationConfiguration.class,
AutoServiceRegistrationAutoConfiguration.class,
NacosDiscoveryAutoConfiguration.class })
public class NacosServiceRegistryAutoConfiguration {
@Bean
public NacosServiceRegistry nacosServiceRegistry(
NacosDiscoveryProperties nacosDiscoveryProperties) {
return new NacosServiceRegistry(nacosDiscoveryProperties);
}
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
public NacosRegistration nacosRegistration(
ObjectProvider<List<NacosRegistrationCustomizer>> registrationCustomizers,
NacosDiscoveryProperties nacosDiscoveryProperties,
ApplicationContext context) {
return new NacosRegistration(registrationCustomizers.getIfAvailable(),
nacosDiscoveryProperties, context);
}
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
public NacosAutoServiceRegistration nacosAutoServiceRegistration(
NacosServiceRegistry registry,
AutoServiceRegistrationProperties autoServiceRegistrationProperties,
NacosRegistration registration) {
return new NacosAutoServiceRegistration(registry,
autoServiceRegistrationProperties, registration);
}
關(guān)鍵類 NacosAutoServiceRegistration 的類圖結(jié)構(gòu)如下
上圖可知，NacosAutoServiceRegistration 實(shí)現(xiàn)了 ApplicationListener接口，該監(jiān)聽器會(huì)在SpringBoot啟動(dòng)的時(shí)候會(huì)自動(dòng)調(diào)用 onApplicationEvent方法，onApplicationEvent具體實(shí)現(xiàn)方法如下
public void onApplicationEvent(WebServerInitializedEvent event) {
this.bind(event);
}
@Deprecated
public void bind(WebServerInitializedEvent event) {
ApplicationContext context = event.getApplicationContext();
if (!(context instanceof ConfigurableWebServerApplicationContext) || !"management".equals(((ConfigurableWebServerApplicationContext)context).getServerNamespace())) {
this.port.compareAndSet(0, event.getWebServer().getPort());
// 具體的啟動(dòng)方法
this.start();
}
}具體的啟動(dòng)方法this.start();方法的代碼如下，
public void start() {
if (!this.isEnabled()) {
if (logger.isDebugEnabled()) {
logger.debug("Discovery Lifecycle disabled. Not starting");
}
} else {
if (!this.running.get()) {
this.context.publishEvent(new InstancePreRegisteredEvent(this, this.getRegistration()));
// 關(guān)鍵邏輯
this.register();
if (this.shouldRegisterManagement()) {
this.registerManagement();
}
this.context.publishEvent(new InstanceRegisteredEvent(this, this.getConfiguration()));
this.running.compareAndSet(false, true);
}
}關(guān)鍵邏輯為this.register();方法代碼如下
protected void register() {
if (!this.registration.getNacosDiscoveryProperties().isRegisterEnabled()) {
log.debug("Registration disabled.");
return;
}
if (this.registration.getPort() < 0) {
this.registration.setPort(getPort().get());
}
super.register();
}關(guān)鍵邏輯為super.register();方法代碼如下，
protected void register() {
this.serviceRegistry.register(this.getRegistration());
}關(guān)鍵邏輯為this.serviceRegistry.register方法代碼如下，
@Override
public void register(Registration registration) {
if (StringUtils.isEmpty(registration.getServiceId())) {
log.warn("No service to register for nacos client...");
return;
}
// 根據(jù)配置屬性構(gòu)建NamingService對(duì)象
NamingService namingService = namingService();
// 獲取服務(wù)名，默認(rèn)為 ${spring.application.name}
String serviceId = registration.getServiceId();
// 獲取組名 ，默認(rèn)為 DEFAULT_GROUP
String group = nacosDiscoveryProperties.getGroup();
// 創(chuàng)建注冊(cè)實(shí)例
Instance instance = getNacosInstanceFromRegistration(registration);
try {
// 發(fā)起注冊(cè)
namingService.registerInstance(serviceId, group, instance);
log.info("nacos registry, {} {} {}:{} register finished", group, serviceId,
instance.getIp(), instance.getPort());
}
catch (Exception e) {
log.error("nacos registry, {} register failed...{},", serviceId,
registration.toString(), e);
// rethrow a RuntimeException if the registration is failed.
// issue : https://github.com/alibaba/spring-cloud-alibaba/issues/1132
rethrowRuntimeException(e);
}
}
先通過getNacosInstanceFromRegistration方法創(chuàng)建實(shí)例對(duì)象，getNacosInstanceFromRegistration代碼如下，
private Instance getNacosInstanceFromRegistration(Registration registration) {
Instance instance = new Instance();
// 獲取服務(wù)ip
instance.setIp(registration.getHost());
// 獲取服務(wù)
instance.setPort(registration.getPort());
// 獲取權(quán)重
instance.setWeight(nacosDiscoveryProperties.getWeight());
// 獲取集群名稱
instance.setClusterName(nacosDiscoveryProperties.getClusterName());
instance.setEnabled(nacosDiscoveryProperties.isInstanceEnabled());
// 獲取元數(shù)據(jù)
instance.setMetadata(registration.getMetadata());
// 獲取是否為臨時(shí)實(shí)例
instance.setEphemeral(nacosDiscoveryProperties.isEphemeral());
return instance;
}然后通過namingService.registerInstance方法發(fā)起注冊(cè)，registerInstance方法的代碼如下，
public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
// 檢查 實(shí)例是否合法
// heart beat timeout must(默認(rèn)15秒) < heart beat interval （默認(rèn)5秒）拋異常
// ip delete timeout must（默認(rèn)30 秒） < heart beat interval（默認(rèn)5秒）拋異常
NamingUtils.checkInstanceIsLegal(instance);
// 構(gòu)建 groupName@@serviceName
String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName);
// 如果是臨時(shí)實(shí)例，則創(chuàng)建心跳信息，定時(shí)給nacos服務(wù)發(fā)送
if (instance.isEphemeral()) {
BeatInfo beatInfo = this.beatReactor.buildBeatInfo(groupedServiceName, instance);
this.beatReactor.addBeatInfo(groupedServiceName, beatInfo);
}
// 向 nacos-service 注冊(cè)實(shí)例
this.serverProxy.registerService(groupedServiceName, groupName, instance);
}先檢查實(shí)例是否合法，然后構(gòu)建服務(wù)名稱，規(guī)則為groupName@@serviceName。通過this.serverProxy.registerService方法向 nacos-service 注冊(cè)實(shí)例，代碼如下，
public void registerService(String serviceName, String groupName, Instance instance) throws NacosException {
NAMING_LOGGER.info("[REGISTER-SERVICE] {} registering service {} with instance: {}", namespaceId, serviceName,instance);
final Map<String, String> params = new HashMap<String, String>(16);
//設(shè)置 namespaceId
params.put(CommonParams.NAMESPACE_ID, namespaceId);
//設(shè)置 serviceName
params.put(CommonParams.SERVICE_NAME, serviceName);
//設(shè)置 groupName
params.put(CommonParams.GROUP_NAME, groupName);
//設(shè)置 clusterName
params.put(CommonParams.CLUSTER_NAME, instance.getClusterName());
params.put("ip", instance.getIp());
params.put("port", String.valueOf(instance.getPort()));
params.put("weight", String.valueOf(instance.getWeight()));
params.put("enable", String.valueOf(instance.isEnabled()));
params.put("healthy", String.valueOf(instance.isHealthy()));
params.put("ephemeral", String.valueOf(instance.isEphemeral()));
params.put("metadata", JacksonUtils.toJson(instance.getMetadata()));
// 調(diào)用 nacos-service 的nacosUrlInstance接口注冊(cè)實(shí)例
reqApi(UtilAndComs.nacosUrlInstance, params, HttpMethod.POST);
}通過向reqApi方法向nacos服務(wù)端注冊(cè)當(dāng)前實(shí)例數(shù)據(jù)，其實(shí)就是向 ${spring.cloud.nacos.discovery.server-addr}/nacos/v1/ns/instance 發(fā)送POST請(qǐng)求。該請(qǐng)求地址對(duì)應(yīng)的nacos服務(wù)端的源碼的naming工程中InstanceController的register方法，代碼如下，
public String register(HttpServletRequest request) throws Exception {
final String namespaceId = WebUtils
.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
final String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
NamingUtils.checkServiceNameFormat(serviceName);
//根據(jù)請(qǐng)求構(gòu)建 Instance 對(duì)象
final Instance instance = parseInstance(request);
//注冊(cè) Instance 對(duì)象，serviceManager對(duì)象中保存了所有的服務(wù)對(duì)象。
serviceManager.registerInstance(namespaceId, serviceName, instance);
return "ok";
}先根據(jù)請(qǐng)求對(duì)象構(gòu)建Instance對(duì)象，然后通過serviceManager.registerInstance方法用來注冊(cè)Instance對(duì)象，registerInstance代碼如下
public void registerInstance(String namespaceId, String serviceName, Instance instance) throws NacosException {
// 如果 namespaceId 為 key 的數(shù)據(jù)為空，則創(chuàng)建 service ，并初始化service
createEmptyService(namespaceId, serviceName, instance.isEphemeral());
// 獲取 service 對(duì)象
Service service = getService(namespaceId, serviceName);
// 如果 service為空 則報(bào)錯(cuò)
if (service == null) {
throw new NacosException(NacosException.INVALID_PARAM,
"service not found, namespace: " + namespaceId + ", service: " + serviceName);
}
// 添加實(shí)例
addInstance(namespaceId, serviceName, instance.isEphemeral(), instance);
}如果 namespaceId為key的數(shù)據(jù)為空，則創(chuàng)建 service，并初始化service。然后調(diào)用addInstance添加實(shí)例對(duì)象，addInstance方法代碼如下，
public void addInstance(String namespaceId, String serviceName, boolean ephemeral, Instance... ips)
throws NacosException {
// 根據(jù) 命名空間 和 服務(wù)名稱 構(gòu)建 key
String key = KeyBuilder.buildInstanceListKey(namespaceId, serviceName, ephemeral);
// 獲取 service
Service service = getService(namespaceId, serviceName);
// 同步鎖
synchronized (service) {
// 獲取服務(wù)下的實(shí)例集合（服務(wù)已有 + 新增的實(shí)例）
List<Instance> instanceList = addIpAddresses(service, ephemeral, ips);
Instances instances = new Instances();
instances.setInstanceList(instanceList);
// 根據(jù)KEY添加服務(wù)的實(shí)例
consistencyService.put(key, instances);
}
}addIpAddresses方法中會(huì)調(diào)用updateIpAddresses方法，且action為 add。該方法根據(jù)action的值來獲取該服務(wù)下的最新實(shí)例集合（新增實(shí)例或刪除實(shí)例加上目前服務(wù)已有的實(shí)例數(shù)據(jù)合集）。如果action為add表示新增，則方法最后返回的集合對(duì)象中會(huì)把該服務(wù)中已有的實(shí)例集合加上新增的實(shí)例集合數(shù)據(jù)一起返回 ；如果action為 remove表示刪除，則方法最后返回的集合對(duì)象中會(huì)把該服務(wù)中已有的實(shí)例集合刪除掉需要?jiǎng)h除的實(shí)例集合數(shù)據(jù)。后面通過調(diào)用consistencyService.put(key, instances)方法來把updateIpAddresses方法返回的值直接添加consistencyService的實(shí)例中。updateIpAddresses方法的代碼如下，
public List<Instance> updateIpAddresses(Service service, String action, boolean ephemeral, Instance... ips)
throws NacosException {
// 從本地緩存中獲取服務(wù)的實(shí)例數(shù)據(jù)
Datum datum = consistencyService
.get(KeyBuilder.buildInstanceListKey(service.getNamespaceId(), service.getName(), ephemeral));
// 獲取 當(dāng)前服務(wù)下所有的 實(shí)例
List<Instance> currentIPs = service.allIPs(ephemeral);
// 創(chuàng)建當(dāng)前實(shí)例數(shù)據(jù)map
Map<String, Instance> currentInstances = new HashMap<>(currentIPs.size());
// 創(chuàng)建 當(dāng)前實(shí)例Id set
Set<String> currentInstanceIds = Sets.newHashSet();
// 遍歷當(dāng)前服務(wù)的所有實(shí)例，添加到 創(chuàng)建當(dāng)前實(shí)例數(shù)據(jù) map 和 當(dāng)前實(shí)例Id集合
for (Instance instance : currentIPs) {
currentInstances.put(instance.toIpAddr(), instance);
currentInstanceIds.add(instance.getInstanceId());
}
// 構(gòu)造 實(shí)例集合對(duì)象的 map
Map<String, Instance> instanceMap;
// 如果有緩存數(shù)據(jù)
if (datum != null && null != datum.value) {
// 從本地緩存中以及當(dāng)前服務(wù)的內(nèi)存數(shù)據(jù)獲取最新服務(wù)的實(shí)例數(shù)據(jù)
instanceMap = setValid(((Instances) datum.value).getInstanceList(), currentInstances);
}
// 如果沒有緩存數(shù)據(jù)
else {
// 創(chuàng)建 instanceMap
instanceMap = new HashMap<>(ips.length);
}
// 遍歷參數(shù)傳過來的實(shí)例對(duì)象
for (Instance instance : ips) {
// 如果 service 不包括 實(shí)例的 ClusterName 則創(chuàng)建 實(shí)例 Cluster，并初始化
if (!service.getClusterMap().containsKey(instance.getClusterName())) {
Cluster cluster = new Cluster(instance.getClusterName(), service);
cluster.init();
service.getClusterMap().put(instance.getClusterName(), cluster);
Loggers.SRV_LOG
.warn("cluster: {} not found, ip: {}, will create new cluster with default configuration.",
instance.getClusterName(), instance.toJson());
}
// 如果是刪除，則從 instanceMap 中 刪除 該實(shí)例
if (UtilsAndCommons.UPDATE_INSTANCE_ACTION_REMOVE.equals(action)) {
instanceMap.remove(instance.getDatumKey());
}
// 如果是新增
else {
//獲取已存在的 實(shí)例
Instance oldInstance = instanceMap.get(instance.getDatumKey());
if (oldInstance != null) {
instance.setInstanceId(oldInstance.getInstanceId());
} else {
// 生成 實(shí)例 id
instance.setInstanceId(instance.generateInstanceId(currentInstanceIds));
}
// instanceMap 添加instance實(shí)例
instanceMap.put(instance.getDatumKey(), instance);
}
}
// 如果集合小于0 ，并且是新增操作則拋異常
if (instanceMap.size() <= 0 && UtilsAndCommons.UPDATE_INSTANCE_ACTION_ADD.equals(action)) {
throw new IllegalArgumentException(
"ip list can not be empty, service: " + service.getName() + ", ip list: " + JacksonUtils
.toJson(instanceMap.values()));
}
// 返回 服務(wù)中最新的實(shí)例數(shù)據(jù)
return new CopyOnWriteArrayList<>(instanceMap.values());
}
通過updateIpAddresses方法拿到需要更新的實(shí)例集合對(duì)象后，再通過consistencyService.put(key, instances)把拿到的實(shí)例集合對(duì)象添加到實(shí)現(xiàn)了PersistentConsistencyServiceDelegateImpl或者EphemeralConsistencyService接口的實(shí)例對(duì)象中，consistencyService.put(key, instances)的源碼如下，
@Override
public void put(String key, Record value) throws NacosException {
// 根據(jù)key獲取具體的 consistencyService ，并且向其中添加具體的 key 和 value
mapConsistencyService(key).put(key, value);
}根據(jù)key獲取具體的 consistencyService ，并且向其中添加具體的 key 和 value。consistencyService中根據(jù)key獲取集群的實(shí)例對(duì)象（臨時(shí)服務(wù)對(duì)象EphemeralConsistencyService和持久服務(wù)對(duì)象PersistentConsistencyServiceDelegateImpl）
private ConsistencyService mapConsistencyService(String key) {
// 根據(jù)key返回具體的服務(wù)對(duì)象
return KeyBuilder.matchEphemeralKey(key) ? ephemeralConsistencyService : persistentConsistencyService;
}
如果是注冊(cè)的臨時(shí)實(shí)例節(jié)點(diǎn)，這里取到的是實(shí)現(xiàn)了ephemeralConsistencyService接口的DistroConsistencyServiceImpl 對(duì)象，它的put源碼如下：
@Override
public void put(String key, Record value) throws NacosException {
// 添加key 和 value
onPut(key, value);
distroProtocol.sync(new DistroKey(key, KeyBuilder.INSTANCE_LIST_KEY_PREFIX), DataOperation.CHANGE,
globalConfig.getTaskDispatchPeriod() / 2);
}通過onPut方法添加key 和 value，opPut方法的代碼如下，
public void onPut(String key, Record value) {
// 如果是臨時(shí)節(jié)點(diǎn)實(shí)例，則創(chuàng)建 Datum 并保存在 dataStore 中
if (KeyBuilder.matchEphemeralInstanceListKey(key)) {
Datum<Instances> datum = new Datum<>();
datum.value = (Instances) value;
datum.key = key;
datum.timestamp.incrementAndGet();
dataStore.put(key, datum);
}
// 如果 監(jiān)聽對(duì)象不包括 key 則返回
if (!listeners.containsKey(key)) {
return;
}
// 向notifier對(duì)象添加通知任務(wù)
notifier.addTask(key, DataOperation.CHANGE);
}如果是臨時(shí)實(shí)例節(jié)點(diǎn)，則創(chuàng)建 Datum 并保存在 dataStore 中，然后通過notifier.addTask用來向notifier對(duì)象添加通知任務(wù)，且操作類型為DataOperation.CHANGE，addTask方法的代碼如下：
public void addTask(String datumKey, DataOperation action) {
// 如果services包括了當(dāng)前的 datumKey ，并且是修改操作 則直接返回
if (services.containsKey(datumKey) && action == DataOperation.CHANGE) {
return;
}
// 如果是修改操作，則向 services 添加 datumKey
if (action == DataOperation.CHANGE) {
services.put(datumKey, StringUtils.EMPTY);
}
// 向 tasks中添加 Pair 對(duì)象
tasks.offer(Pair.with(datumKey, action));
}以上代碼的tasks是用來存放具體實(shí)例key和動(dòng)作類型的對(duì)象，它是一個(gè)ArrayBlockingQueue對(duì)象，DistroConsistencyServiceImpl 對(duì)象的init方法代碼如下，
@PostConstruct
public void init() {
GlobalExecutor.submitDistroNotifyTask(notifier);
}根據(jù)以上代碼可知，在DistroConsistencyServiceImpl 實(shí)例對(duì)象初始化之后會(huì)往GlobalExecutor線程池對(duì)象中添加了一個(gè)notifier對(duì)象。notifier對(duì)象為一個(gè)實(shí)現(xiàn)了Runnable 的實(shí)例。上面的代碼會(huì)執(zhí)行notifier對(duì)象的run方法，notifier的run方法代碼如下：
public void run() {
Loggers.DISTRO.info("distro notifier started");
// 死循環(huán)遍歷
for (; ; ) {
try {
// 獲取 tasks的數(shù)據(jù)，如果沒有數(shù)據(jù)會(huì)阻塞當(dāng)前線程，直到tasks有數(shù)據(jù)為止。
Pair<String, DataOperation> pair = tasks.take();
// 處理數(shù)據(jù)
handle(pair);
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] Error while handling notifying task", e);
}
}
}上面是一個(gè)死循環(huán)，tasks.take()是一個(gè)阻塞式獲取數(shù)據(jù)的方法，如果tasks沒有數(shù)據(jù)則會(huì)阻塞當(dāng)前線程直到tasks.take()拿到數(shù)據(jù)，拿到數(shù)據(jù)之后會(huì)調(diào)用handle方法處理，handle代碼如下，
private void handle(Pair<String, DataOperation> pair) {
try {
String datumKey = pair.getValue0();
DataOperation action = pair.getValue1();
// 先從 services 中刪除 key
services.remove(datumKey);
int count = 0;
// 根據(jù) key 獲取 服務(wù)對(duì)象數(shù)據(jù)
ConcurrentLinkedQueue<RecordListener> recordListeners = listeners.get(datumKey);
if (recordListeners == null) {
Loggers.DISTRO.info("[DISTRO-WARN] RecordListener not found, key: {}", datumKey);
return;
}
for (RecordListener listener : recordListeners) {
count++;
try {
// 如果是新增
if (action == DataOperation.CHANGE) {
Datum datum = dataStore.get(datumKey);
if (datum != null) {
// 更新 serivce 的實(shí)例數(shù)據(jù)
listener.onChange(datumKey, datum.value);
} else {
Loggers.DISTRO.info("[DISTRO-WARN] data not found, key: {}", datumKey);
}
continue;
}
// 如果是刪除
if (action == DataOperation.DELETE) {
listener.onDelete(datumKey);
continue;
}
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] error while notifying listener of key: {}", datumKey, e);
}
}
if (Loggers.DISTRO.isDebugEnabled()) {
Loggers.DISTRO
.debug("[NACOS-DISTRO] datum change notified, key: {}, listener count: {}, action: {}",
datumKey, count, action.name());
}
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] Error while handling notifying task", e);
}
}
根據(jù)action 為 DataOperation.CHANGE，代碼中執(zhí)行的代碼分支為listener.onChange(datumKey, datum.value)，該方法的邏輯為修改服務(wù)的實(shí)例數(shù)據(jù)，源碼如下
public void onChange(String key, Instances value) throws Exception {
Loggers.SRV_LOG.info("[NACOS-RAFT] datum is changed, key: {}, value: {}", key, value);
for (Instance instance : value.getInstanceList()) {
if (instance == null) {
// Reject this abnormal instance list:
throw new RuntimeException("got null instance " + key);
}
if (instance.getWeight() > 10000.0D) {
instance.setWeight(10000.0D);
}
if (instance.getWeight() < 0.01D && instance.getWeight() > 0.0D) {
instance.setWeight(0.01D);
}
}
// 更新 service 的 實(shí)例集合
updateIPs(value.getInstanceList(), KeyBuilder.matchEphemeralInstanceListKey(key));
recalculateChecksum();
}以上代碼先遍歷所有的實(shí)例數(shù)據(jù)設(shè)置權(quán)值，再通過updateIPs方法更新服務(wù)實(shí)例，updateIPs方法的代碼如下：
public void updateIPs(Collection<Instance> instances, boolean ephemeral) {
// 根據(jù) clusterMap 創(chuàng)建 ipMap對(duì)象
Map<String, List<Instance>> ipMap = new HashMap<>(clusterMap.size());
// 根據(jù) clusterMap 初始化 ipMap對(duì)象
for (String clusterName : clusterMap.keySet()) {
ipMap.put(clusterName, new ArrayList<>());
}
// 遍歷最新的實(shí)例集合數(shù)據(jù)
for (Instance instance : instances) {
try {
if (instance == null) {
Loggers.SRV_LOG.error("[NACOS-DOM] received malformed ip: null");
continue;
}
// 如果集群名稱為null ，則設(shè)置默認(rèn)的集群名稱 DEFAULT
if (StringUtils.isEmpty(instance.getClusterName())) {
instance.setClusterName(UtilsAndCommons.DEFAULT_CLUSTER_NAME);
}
// 如果當(dāng)前 service 的clusterMap不包括 實(shí)例的 集群名稱，則需要?jiǎng)?chuàng)建新的集群對(duì)象
if (!clusterMap.containsKey(instance.getClusterName())) {
Loggers.SRV_LOG
.warn("cluster: {} not found, ip: {}, will create new cluster with default configuration.",
instance.getClusterName(), instance.toJson());
Cluster cluster = new Cluster(instance.getClusterName(), this);
cluster.init();
getClusterMap().put(instance.getClusterName(), cluster);
}
// 如果當(dāng)前 ipMap 不包括 當(dāng)前實(shí)例的 集群名稱，則需要?jiǎng)?chuàng)建新的集群對(duì)象
List<Instance> clusterIPs = ipMap.get(instance.getClusterName());
if (clusterIPs == null) {
clusterIPs = new LinkedList<>();
ipMap.put(instance.getClusterName(), clusterIPs);
}
// 給當(dāng)前的 集群對(duì)象賦值 實(shí)例數(shù)據(jù)。
clusterIPs.add(instance);
} catch (Exception e) {
Loggers.SRV_LOG.error("[NACOS-DOM] failed to process ip: " + instance, e);
}
}
// 遍歷 ipMap對(duì)象，給 clusterMap 替換最新的 entryIPs
for (Map.Entry<String, List<Instance>> entry : ipMap.entrySet()) {
//make every ip mine
List<Instance> entryIPs = entry.getValue();
// 給 clusterMap 替換最新的 entryIPs
clusterMap.get(entry.getKey()).updateIps(entryIPs, ephemeral);
}
setLastModifiedMillis(System.currentTimeMillis());
// 發(fā)布
getPushService().serviceChanged(this);
StringBuilder stringBuilder = new StringBuilder();
for (Instance instance : allIPs()) {
stringBuilder.append(instance.toIpAddr()).append("_").append(instance.isHealthy()).append(",");
}
Loggers.EVT_LOG.info("[IP-UPDATED] namespace: {}, service: {}, ips: {}", getNamespaceId(), getName(),
stringBuilder.toString());
}
以上代碼先根據(jù)當(dāng)前服務(wù)下的集群信息構(gòu)造構(gòu)造ipMap對(duì)象，然后遍歷最新的實(shí)例集合數(shù)據(jù)更新ipMap對(duì)象，最后循環(huán)調(diào)用clusterMap.get(entry.getKey()).updateIps(entryIPs, ephemeral)方法來更新當(dāng)前集群中的實(shí)例列表數(shù)據(jù)。updateIps方法代碼如下：
public void updateIps(List<Instance> ips, boolean ephemeral) {
// 獲取 本集群中的 實(shí)例集合
Set<Instance> toUpdateInstances = ephemeral ? ephemeralInstances : persistentInstances;
// 根據(jù)old的實(shí)例數(shù)據(jù) 構(gòu)建 hashmap
HashMap<String, Instance> oldIpMap = new HashMap<>(toUpdateInstances.size());
// 根據(jù)實(shí)例的 key 添加到 oldIpMap中
for (Instance ip : toUpdateInstances) {
oldIpMap.put(ip.getDatumKey(), ip);
}
// 獲取更新的 實(shí)例數(shù)據(jù) List
List<Instance> updatedIPs = updatedIps(ips, oldIpMap.values());
if (updatedIPs.size() > 0) {
for (Instance ip : updatedIPs) {
Instance oldIP = oldIpMap.get(ip.getDatumKey());
// do not update the ip validation status of updated ips
// because the checker has the most precise result
// Only when ip is not marked, don't we update the health status of IP:
if (!ip.isMarked()) {
ip.setHealthy(oldIP.isHealthy());
}
if (ip.isHealthy() != oldIP.isHealthy()) {
// ip validation status updated
Loggers.EVT_LOG.info("{} {SYNC} IP-{} {}:{}@{}", getService().getName(),
(ip.isHealthy() ? "ENABLED" : "DISABLED"), ip.getIp(), ip.getPort(), getName());
}
if (ip.getWeight() != oldIP.getWeight()) {
// ip validation status updated
Loggers.EVT_LOG.info("{} {SYNC} {IP-UPDATED} {}->{}", getService().getName(), oldIP.toString(),
ip.toString());
}
}
}
// 獲取新增的 實(shí)例數(shù)據(jù)
List<Instance> newIPs = subtract(ips, oldIpMap.values());
if (newIPs.size() > 0) {
Loggers.EVT_LOG
.info("{} {SYNC} {IP-NEW} cluster: {}, new ips size: {}, content: {}", getService().getName(),
getName(), newIPs.size(), newIPs.toString());
for (Instance ip : newIPs) {
HealthCheckStatus.reset(ip);
}
}
// 獲取刪除的 實(shí)例數(shù)據(jù)
List<Instance> deadIPs = subtract(oldIpMap.values(), ips);
if (deadIPs.size() > 0) {
Loggers.EVT_LOG
.info("{} {SYNC} {IP-DEAD} cluster: {}, dead ips size: {}, content: {}", getService().getName(),
getName(), deadIPs.size(), deadIPs.toString());
for (Instance ip : deadIPs) {
HealthCheckStatus.remv(ip);
}
}
// 根據(jù)傳進(jìn)來的 實(shí)例集合 創(chuàng)建需要更新的實(shí)例set
toUpdateInstances = new HashSet<>(ips);
// 直接替換
if (ephemeral) {
ephemeralInstances = toUpdateInstances;
} else {
persistentInstances = toUpdateInstances;
}
以上代碼就是更新cluster對(duì)象下的實(shí)例數(shù)據(jù)邏輯，根據(jù)代碼可知在cluster對(duì)象中更新實(shí)例數(shù)據(jù)就是拿傳進(jìn)來的實(shí)例列表創(chuàng)建set集合直接替換的。
二、服務(wù)實(shí)例列表拉取
客戶端程序啟動(dòng)之后，會(huì)執(zhí)行com.alibaba.cloud.nacos.discovery.NacosWatch類的start()方法，此方法中會(huì)執(zhí)行以下語句，
namingService.subscribe(properties.getService(), properties.getGroup(),
Arrays.asList(properties.getClusterName()), eventListener);此方法用來獲取當(dāng)前服務(wù)的實(shí)例數(shù)據(jù)，subscribe方法代碼如下，
public void subscribe(String serviceName, String groupName, List<String> clusters, EventListener listener)
throws NacosException {
// 獲取服務(wù)列表數(shù)據(jù)
hostReactor.subscribe(NamingUtils.getGroupedName(serviceName, groupName), StringUtils.join(clusters, ","),
listener);
}通過hostReactor.subscribe方法獲取服務(wù)列表數(shù)據(jù)，subscribe方法的代碼如下，
public void subscribe(String serviceName, String clusters, EventListener eventListener) {
notifier.registerListener(serviceName, clusters, eventListener);
// 獲取服務(wù)列表數(shù)據(jù)
getServiceInfo(serviceName, clusters);
}通過getServiceInfo方法獲取服務(wù)列表數(shù)據(jù)，getServiceInfo的代碼如下：
NAMING_LOGGER.debug("failover-mode: " + failoverReactor.isFailoverSwitch());
String key = ServiceInfo.getKey(serviceName, clusters);
if (failoverReactor.isFailoverSwitch()) {
return failoverReactor.getService(key);
}
// 根據(jù)服務(wù)名稱和集群名稱獲取本地的服務(wù)列表數(shù)據(jù)
ServiceInfo serviceObj = getServiceInfo0(serviceName, clusters);
if (null == serviceObj) {
serviceObj = new ServiceInfo(serviceName, clusters);
serviceInfoMap.put(serviceObj.getKey(), serviceObj);
updatingMap.put(serviceName, new Object());
// 如果本地服務(wù)實(shí)例數(shù)據(jù)為null，則去獲取最新的服務(wù)實(shí)例列表
updateServiceNow(serviceName, clusters);
updatingMap.remove(serviceName);
} else if (updatingMap.containsKey(serviceName)) {
if (UPDATE_HOLD_INTERVAL > 0) {
// hold a moment waiting for update finish
synchronized (serviceObj) {
try {
serviceObj.wait(UPDATE_HOLD_INTERVAL);
} catch (InterruptedException e) {
NAMING_LOGGER
.error("[getServiceInfo] serviceName:" + serviceName + ", clusters:" + clusters, e);
}
}
}
}
scheduleUpdateIfAbsent(serviceName, clusters);
return serviceInfoMap.get(serviceObj.getKey());
以上代碼可知，會(huì)根據(jù)服務(wù)名稱和clusters名稱獲取本地緩存serviceInfoMap對(duì)象中的服務(wù)列表數(shù)據(jù)。如果本地服務(wù)實(shí)例數(shù)據(jù)為null，則通過updateServiceNow方法去nacos服務(wù)端獲取最新的服務(wù)實(shí)例列表。updateServiceNow方法代碼如下：
try {
// 更新本地服務(wù)方法
updateService(serviceName, clusters);
} catch (NacosException e) {
NAMING_LOGGER.error("[NA] failed to update serviceName: " + serviceName, e);
}updateService的代碼如下：
public void updateService(String serviceName, String clusters) throws NacosException {
ServiceInfo oldService = getServiceInfo0(serviceName, clusters);
try {
// 調(diào)用服務(wù)代理類獲取服務(wù)實(shí)例列表，pushReceiver.getUdpPort()會(huì)隨機(jī)生成一個(gè)udp端口
String result = serverProxy.queryList(serviceName, clusters, pushReceiver.getUdpPort(), false);
if (StringUtils.isNotEmpty(result)) {
// 如果 result不為空，則向本地緩存 serviceInfoMap 添加服務(wù)實(shí)例列表
processServiceJson(result);
}
} finally {
if (oldService != null) {
synchronized (oldService) {
oldService.notifyAll();
}
}
}
}通過調(diào)用服務(wù)代理類serverProxy的queryList方法獲取服務(wù)實(shí)例列表，pushReceiver.getUdpPort()會(huì)獲pushReceiver的udp端口，pushReceiver對(duì)象是一個(gè)udp數(shù)據(jù)接收類，用來接收nacos服務(wù)器發(fā)送的udp數(shù)據(jù)，比如服務(wù)實(shí)例更新的消息。serverProxy.query方法的代碼如下：
public String queryList(String serviceName, String clusters, int udpPort, boolean healthyOnly)
throws NacosException {
// 構(gòu)造請(qǐng)求參數(shù)
final Map<String, String> params = new HashMap<String, String>(8);
params.put(CommonParams.NAMESPACE_ID, namespaceId);
params.put(CommonParams.SERVICE_NAME, serviceName);
params.put("clusters", clusters);
// 客戶端的upd端口，服務(wù)端回調(diào)客戶端udp端口會(huì)用到
params.put("udpPort", String.valueOf(udpPort));
params.put("clientIP", NetUtils.localIP());
params.put("healthyOnly", String.valueOf(healthyOnly));
// 向nacos服務(wù)器獲取服務(wù)列表數(shù)據(jù)，并返回
return reqApi(UtilAndComs.nacosUrlBase + "/instance/list", params, HttpMethod.GET);
}在構(gòu)造的請(qǐng)求參數(shù)中包括了客戶端的udpPort，該參數(shù)在服務(wù)端回調(diào)接口會(huì)用到。reqApi方法其實(shí)就向nacos服務(wù)器的/nacos/v1/ns/instance/list接口發(fā)送了請(qǐng)求消息，該接口對(duì)應(yīng)的nacos服務(wù)端的源碼的naming工程中InstanceController的list方法，代碼如下，
@GetMapping("/list")
@Secured(parser = NamingResourceParser.class, action = ActionTypes.READ)
public ObjectNode list(HttpServletRequest request) throws Exception {
String namespaceId = WebUtils.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
NamingUtils.checkServiceNameFormat(serviceName);
String agent = WebUtils.getUserAgent(request);
String clusters = WebUtils.optional(request, "clusters", StringUtils.EMPTY);
String clientIP = WebUtils.optional(request, "clientIP", StringUtils.EMPTY);
int udpPort = Integer.parseInt(WebUtils.optional(request, "udpPort", "0"));
String env = WebUtils.optional(request, "env", StringUtils.EMPTY);
boolean isCheck = Boolean.parseBoolean(WebUtils.optional(request, "isCheck", "false"));
String app = WebUtils.optional(request, "app", StringUtils.EMPTY);
String tenant = WebUtils.optional(request, "tid", StringUtils.EMPTY);
boolean healthyOnly = Boolean.parseBoolean(WebUtils.optional(request, "healthyOnly", "false"));
// 獲取實(shí)例列表數(shù)據(jù)
return doSrvIpxt(namespaceId, serviceName, agent, clusters, clientIP, udpPort, env, isCheck, app, tenant,
healthyOnly);
}以上代碼先構(gòu)造相關(guān)參數(shù)信息，然后通過doSrvIpxt方法來獲取實(shí)例列表數(shù)據(jù)，doSrvIpxt代碼如下：
public ObjectNode doSrvIpxt(String namespaceId, String serviceName, String agent, String clusters, String clientIP,
int udpPort, String env, boolean isCheck, String app, String tid, boolean healthyOnly) throws Exception {
ClientInfo clientInfo = new ClientInfo(agent);
ObjectNode result = JacksonUtils.createEmptyJsonNode();
// 根據(jù)命名空間id和服務(wù)名稱獲取服務(wù)
Service service = serviceManager.getService(namespaceId, serviceName);
long cacheMillis = switchDomain.getDefaultCacheMillis();
// now try to enable the push
try {
// 如果端口大于0 ，并且是支持的客戶端
if (udpPort > 0 && pushService.canEnablePush(agent)) {
// 添加 PushClient 對(duì)象
pushService
.addClient(namespaceId, serviceName, clusters, agent, new InetSocketAddress(clientIP, udpPort),
pushDataSource, tid, app);
cacheMillis = switchDomain.getPushCacheMillis(serviceName);
}
} catch (Exception e) {
Loggers.SRV_LOG
.error("[NACOS-API] failed to added push client {}, {}:{}", clientInfo, clientIP, udpPort, e);
cacheMillis = switchDomain.getDefaultCacheMillis();
}
// 如果服務(wù)對(duì)象為 null ，則構(gòu)造數(shù)據(jù)返回
if (service == null) {
if (Loggers.SRV_LOG.isDebugEnabled()) {
Loggers.SRV_LOG.debug("no instance to serve for service: {}", serviceName);
}
result.put("name", serviceName);
result.put("clusters", clusters);
result.put("cacheMillis", cacheMillis);
result.replace("hosts", JacksonUtils.createEmptyArrayNode());
return result;
}
// 檢查服務(wù)是否可用
checkIfDisabled(service);
List<Instance> srvedIPs;
// 根據(jù)集群列表獲取具體服務(wù)下面的實(shí)例列表
srvedIPs = service.srvIPs(Arrays.asList(StringUtils.split(clusters, ",")));
// filter ips using selector:
if (service.getSelector() != null && StringUtils.isNotBlank(clientIP)) {
srvedIPs = service.getSelector().select(clientIP, srvedIPs);
}
// 如果實(shí)例數(shù)據(jù)為空，則構(gòu)造數(shù)據(jù)返回
if (CollectionUtils.isEmpty(srvedIPs)) {
if (Loggers.SRV_LOG.isDebugEnabled()) {
Loggers.SRV_LOG.debug("no instance to serve for service: {}", serviceName);
}
if (clientInfo.type == ClientInfo.ClientType.JAVA
&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {
result.put("dom", serviceName);
} else {
result.put("dom", NamingUtils.getServiceName(serviceName));
}
result.put("name", serviceName);
result.put("cacheMillis", cacheMillis);
result.put("lastRefTime", System.currentTimeMillis());
result.put("checksum", service.getChecksum());
result.put("useSpecifiedURL", false);
result.put("clusters", clusters);
result.put("env", env);
result.set("hosts", JacksonUtils.createEmptyArrayNode());
result.set("metadata", JacksonUtils.transferToJsonNode(service.getMetadata()));
return result;
}
Map<Boolean, List<Instance>> ipMap = new HashMap<>(2);
ipMap.put(Boolean.TRUE, new ArrayList<>());
ipMap.put(Boolean.FALSE, new ArrayList<>());
// 構(gòu)造健康和不健康的實(shí)例數(shù)據(jù)
for (Instance ip : srvedIPs) {
ipMap.get(ip.isHealthy()).add(ip);
}
if (isCheck) {
result.put("reachProtectThreshold", false);
}
double threshold = service.getProtectThreshold();
if ((float) ipMap.get(Boolean.TRUE).size() / srvedIPs.size() <= threshold) {
Loggers.SRV_LOG.warn("protect threshold reached, return all ips, service: {}", serviceName);
if (isCheck) {
result.put("reachProtectThreshold", true);
}
ipMap.get(Boolean.TRUE).addAll(ipMap.get(Boolean.FALSE));
ipMap.get(Boolean.FALSE).clear();
}
if (isCheck) {
result.put("protectThreshold", service.getProtectThreshold());
result.put("reachLocalSiteCallThreshold", false);
return JacksonUtils.createEmptyJsonNode();
}
ArrayNode hosts = JacksonUtils.createEmptyArrayNode();
// 構(gòu)造返回的實(shí)例列表對(duì)象
for (Map.Entry<Boolean, List<Instance>> entry : ipMap.entrySet()) {
List<Instance> ips = entry.getValue();
if (healthyOnly && !entry.getKey()) {
continue;
}
for (Instance instance : ips) {
// remove disabled instance:
if (!instance.isEnabled()) {
continue;
}
ObjectNode ipObj = JacksonUtils.createEmptyJsonNode();
ipObj.put("ip", instance.getIp());
ipObj.put("port", instance.getPort());
// deprecated since nacos 1.0.0:
ipObj.put("valid", entry.getKey());
ipObj.put("healthy", entry.getKey());
ipObj.put("marked", instance.isMarked());
ipObj.put("instanceId", instance.getInstanceId());
ipObj.set("metadata", JacksonUtils.transferToJsonNode(instance.getMetadata()));
ipObj.put("enabled", instance.isEnabled());
ipObj.put("weight", instance.getWeight());
ipObj.put("clusterName", instance.getClusterName());
if (clientInfo.type == ClientInfo.ClientType.JAVA
&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {
ipObj.put("serviceName", instance.getServiceName());
} else {
ipObj.put("serviceName", NamingUtils.getServiceName(instance.getServiceName()));
}
ipObj.put("ephemeral", instance.isEphemeral());
hosts.add(ipObj);
}
}
result.replace("hosts", hosts);
if (clientInfo.type == ClientInfo.ClientType.JAVA
&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {
result.put("dom", serviceName);
} else {
result.put("dom", NamingUtils.getServiceName(serviceName));
}
result.put("name", serviceName);
result.put("cacheMillis", cacheMillis);
result.put("lastRefTime", System.currentTimeMillis());
result.put("checksum", service.getChecksum());
result.put("useSpecifiedURL", false);
result.put("clusters", clusters);
result.put("env", env);
result.replace("metadata", JacksonUtils.transferToJsonNode(service.getMetadata()));
return result;
}
以上代碼其實(shí)就是根據(jù)命名空間id和服務(wù)名稱獲取服務(wù)對(duì)象，然后根據(jù)不同情況構(gòu)造返回對(duì)象，正常情況會(huì)構(gòu)造一個(gè)ServiceInfo類型的ObjectNode對(duì)象，整個(gè)具體過程請(qǐng)看上面的代碼注釋。最后返回構(gòu)造的對(duì)象。
客戶端中拿到請(qǐng)求/nacos/v1/ns/instance/list接口的返回值之后會(huì)轉(zhuǎn)成一個(gè)ServiceInfo對(duì)象，并且把該對(duì)象賦值給本地的緩存對(duì)象serviceInfoMap，processServiceJson關(guān)鍵代碼如下：
// 將返回值轉(zhuǎn)換成 ServiceInfo 類型的對(duì)象 ServiceInfo serviceInfo = JacksonUtils.toObj(json, ServiceInfo.class); // 把該對(duì)象添加到本地緩存中 serviceInfoMap.put(serviceInfo.getKey(), serviceInfo);
三、定時(shí)心跳任務(wù)
在客戶端向nacos服務(wù)端注冊(cè)服務(wù)的過程中，會(huì)調(diào)用com.alibaba.nacos.client.naming.NacosNamingService#registerInstance(java.lang.String, java.lang.String, com.alibaba.nacos.api.naming.pojo.Instance)方法，在該代碼中有個(gè)判斷邏輯，如果是臨時(shí)實(shí)例則會(huì)創(chuàng)建一個(gè)BeatInfo對(duì)象添加到beatReactor中。代碼如下：
public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
// 檢查 實(shí)例是否合法
// heart beat timeout must(默認(rèn)15秒) > heart beat interval （默認(rèn)5秒）
// ip delete timeout must（默認(rèn)30 秒） > heart beat interval
NamingUtils.checkInstanceIsLegal(instance);
// 構(gòu)建 groupName@@serviceName
String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName);
// 如果是臨時(shí)實(shí)例，則創(chuàng)建心跳信息，定時(shí)給nacos服務(wù)發(fā)送
if (instance.isEphemeral()) {
// 構(gòu)造心跳信息
BeatInfo beatInfo = this.beatReactor.buildBeatInfo(groupedServiceName, instance);
// 執(zhí)行心跳定時(shí)任務(wù)
this.beatReactor.addBeatInfo(groupedServiceName, beatInfo);
}
// 向 nacos-service 注冊(cè)實(shí)例
this.serverProxy.registerService(groupedServiceName, groupName, instance);
}beatInfo對(duì)象用來存儲(chǔ)心跳信息，buildBeatInfo方法代碼如下，
public BeatInfo buildBeatInfo(String groupedServiceName, Instance instance) {
BeatInfo beatInfo = new BeatInfo();
beatInfo.setServiceName(groupedServiceName);
beatInfo.setIp(instance.getIp());
beatInfo.setPort(instance.getPort());
beatInfo.setCluster(instance.getClusterName());
beatInfo.setWeight(instance.getWeight());
beatInfo.setMetadata(instance.getMetadata());
beatInfo.setScheduled(false);
beatInfo.setPeriod(instance.getInstanceHeartBeatInterval());
return beatInfo;
}beatReactor中有一個(gè)ScheduledExecutorService類型的executorService實(shí)例用來執(zhí)行定時(shí)的線程，addBeatInfo的代碼如下，
public void addBeatInfo(String serviceName, BeatInfo beatInfo) {
NAMING_LOGGER.info("[BEAT] adding beat: {} to beat map.", beatInfo);
String key = buildKey(serviceName, beatInfo.getIp(), beatInfo.getPort());
BeatInfo existBeat = null;
//fix #1733
if ((existBeat = dom2Beat.remove(key)) != null) {
existBeat.setStopped(true);
}
dom2Beat.put(key, beatInfo);
// 線程池添加定時(shí)任務(wù)，默認(rèn) 5 秒鐘之后 執(zhí)行 BeatTask
executorService.schedule(new BeatTask(beatInfo), beatInfo.getPeriod(), TimeUnit.MILLISECONDS);
MetricsMonitor.getDom2BeatSizeMonitor().set(dom2Beat.size());
}根據(jù)上面的executorService.schedule()代碼可知，BeatTask線程在固定的秒數(shù)之后執(zhí)行，而BeatTask實(shí)現(xiàn)了Runnable接口，即執(zhí)行BeatTask的run方法 。BeatTask的run方法代碼如下，
public void run() {
// 如果 beatInfo 設(shè)置了 stop ，則停止
if (beatInfo.isStopped()) {
return;
}
// 獲取下一次延期執(zhí)行的時(shí)間
long nextTime = beatInfo.getPeriod();
try {
// 向服務(wù)端發(fā)送心跳信息
JsonNode result = serverProxy.sendBeat(beatInfo, BeatReactor.this.lightBeatEnabled);
long interval = result.get("clientBeatInterval").asLong();
boolean lightBeatEnabled = false;
if (result.has(CommonParams.LIGHT_BEAT_ENABLED)) {
lightBeatEnabled = result.get(CommonParams.LIGHT_BEAT_ENABLED).asBoolean();
}
BeatReactor.this.lightBeatEnabled = lightBeatEnabled;
if (interval > 0) {
nextTime = interval;
}
int code = NamingResponseCode.OK;
if (result.has(CommonParams.CODE)) {
code = result.get(CommonParams.CODE).asInt();
}
if (code == NamingResponseCode.RESOURCE_NOT_FOUND) {
Instance instance = new Instance();
instance.setPort(beatInfo.getPort());
instance.setIp(beatInfo.getIp());
instance.setWeight(beatInfo.getWeight());
instance.setMetadata(beatInfo.getMetadata());
instance.setClusterName(beatInfo.getCluster());
instance.setServiceName(beatInfo.getServiceName());
instance.setInstanceId(instance.getInstanceId());
instance.setEphemeral(true);
try {
serverProxy.registerService(beatInfo.getServiceName(),
NamingUtils.getGroupName(beatInfo.getServiceName()), instance);
} catch (Exception ignore) {
}
}
} catch (NacosException ex) {
NAMING_LOGGER.error("[CLIENT-BEAT] failed to send beat: {}, code: {}, msg: {}",
JacksonUtils.toJson(beatInfo), ex.getErrCode(), ex.getErrMsg());
}
// 重新提交定時(shí)任務(wù)，延期發(fā)送心跳信息
executorService.schedule(new BeatTask(beatInfo), nextTime, TimeUnit.MILLISECONDS);
}
以上代碼先獲取下一次延期執(zhí)行的時(shí)間，再通過serverProxy.sendBeat()向服務(wù)端發(fā)送心跳信息，最后重新提交定時(shí)任務(wù)，延期發(fā)送心跳信息，serverProxy.sendBeat()代碼如下，
public JsonNode sendBeat(BeatInfo beatInfo, boolean lightBeatEnabled) throws NacosException {
if (NAMING_LOGGER.isDebugEnabled()) {
NAMING_LOGGER.debug("[BEAT] {} sending beat to server: {}", namespaceId, beatInfo.toString());
}
Map<String, String> params = new HashMap<String, String>(8);
Map<String, String> bodyMap = new HashMap<String, String>(2);
if (!lightBeatEnabled) {
bodyMap.put("beat", JacksonUtils.toJson(beatInfo));
}
params.put(CommonParams.NAMESPACE_ID, namespaceId);
params.put(CommonParams.SERVICE_NAME, beatInfo.getServiceName());
params.put(CommonParams.CLUSTER_NAME, beatInfo.getCluster());
params.put("ip", beatInfo.getIp());
params.put("port", String.valueOf(beatInfo.getPort()));
// 向nacos服務(wù)器發(fā)送心跳數(shù)據(jù)，并返回
String result = reqApi(UtilAndComs.nacosUrlBase + "/instance/beat", params, bodyMap, HttpMethod.PUT);
return JacksonUtils.toObj(result);
}reqApi方法其實(shí)就向nacos服務(wù)器端的/nacos/v1/ns/instance/beat接口發(fā)送了put類型的請(qǐng)求消息，該接口對(duì)應(yīng)的nacos服務(wù)端的源碼的naming工程中InstanceController的beat方法，beat方法的代碼如下，
@CanDistro
@PutMapping("/beat")
@Secured(parser = NamingResourceParser.class, action = ActionTypes.WRITE)
public ObjectNode beat(HttpServletRequest request) throws Exception {
ObjectNode result = JacksonUtils.createEmptyJsonNode();
result.put(SwitchEntry.CLIENT_BEAT_INTERVAL, switchDomain.getClientBeatInterval());
// 獲取心跳信息
String beat = WebUtils.optional(request, "beat", StringUtils.EMPTY);
RsInfo clientBeat = null;
// 如果 beat 數(shù)據(jù)不為空，則構(gòu)造 RsInfo 類型的 clientBeat 實(shí)例
if (StringUtils.isNotBlank(beat)) {
clientBeat = JacksonUtils.toObj(beat, RsInfo.class);
}
// 獲取集群名稱
String clusterName = WebUtils
.optional(request, CommonParams.CLUSTER_NAME, UtilsAndCommons.DEFAULT_CLUSTER_NAME);
// 獲取 實(shí)例的 ip
String ip = WebUtils.optional(request, "ip", StringUtils.EMPTY);
// 獲取 實(shí)例的 端口
int port = Integer.parseInt(WebUtils.optional(request, "port", "0"));
// 如果 clientBeat 不為空，則設(shè)置 相關(guān)的信息
if (clientBeat != null) {
if (StringUtils.isNotBlank(clientBeat.getCluster())) {
clusterName = clientBeat.getCluster();
} else {
// fix #2533
clientBeat.setCluster(clusterName);
}
ip = clientBeat.getIp();
port = clientBeat.getPort();
}
// 獲取 namespaceId
String namespaceId = WebUtils.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
// 獲取 serviceName
String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
// 檢查 ServiceName 的格式
NamingUtils.checkServiceNameFormat(serviceName);
Loggers.SRV_LOG.debug("[CLIENT-BEAT] full arguments: beat: {}, serviceName: {}", clientBeat, serviceName);
// 根據(jù) 參數(shù) 獲取 具體的實(shí)例
Instance instance = serviceManager.getInstance(namespaceId, serviceName, clusterName, ip, port);
// 如果 實(shí)例為 空
if (instance == null) {
// 如果 clientBeat 為空 則構(gòu)造參數(shù) code 為 20404的結(jié)果返回
if (clientBeat == null) {
result.put(CommonParams.CODE, NamingResponseCode.RESOURCE_NOT_FOUND);
return result;
}
Loggers.SRV_LOG.warn("[CLIENT-BEAT] The instance has been removed for health mechanism, "
+ "perform data compensation operations, beat: {}, serviceName: {}", clientBeat, serviceName);
// 如果 clientBeat 不為空 則構(gòu)造 instance 數(shù)據(jù)，向 serviceManager 注冊(cè)實(shí)例。
instance = new Instance();
instance.setPort(clientBeat.getPort());
instance.setIp(clientBeat.getIp());
instance.setWeight(clientBeat.getWeight());
instance.setMetadata(clientBeat.getMetadata());
instance.setClusterName(clusterName);
instance.setServiceName(serviceName);
instance.setInstanceId(instance.getInstanceId());
instance.setEphemeral(clientBeat.isEphemeral());
serviceManager.registerInstance(namespaceId, serviceName, instance);
}
// 根據(jù)服務(wù)名稱獲取 服務(wù)
Service service = serviceManager.getService(namespaceId, serviceName);
// 如果服務(wù)為空 ，則拋異常
if (service == null) {
throw new NacosException(NacosException.SERVER_ERROR,
"service not found: " + serviceName + "@" + namespaceId);
}
// 如果 clientBeat 為空，則創(chuàng)建該對(duì)象
if (clientBeat == null) {
clientBeat = new RsInfo();
clientBeat.setIp(ip);
clientBeat.setPort(port);
clientBeat.setCluster(clusterName);
}
// 處理客戶端的 心跳對(duì)象
service.processClientBeat(clientBeat);
//
result.put(CommonParams.CODE, NamingResponseCode.OK);
if (instance.containsMetadata(PreservedMetadataKeys.HEART_BEAT_INTERVAL)) {
result.put(SwitchEntry.CLIENT_BEAT_INTERVAL, instance.getInstanceHeartBeatInterval());
}
result.put(SwitchEntry.LIGHT_BEAT_ENABLED, switchDomain.isLightBeatEnabled());
return result;
}先獲取心跳信息，然后構(gòu)造RsInfo類型的clientBeat實(shí)例。然后通過service.processClientBeat(clientBeat)方法處理客戶端的心跳對(duì)象，processClientBeat方法的代碼如下，
public void processClientBeat(final RsInfo rsInfo) {
// 構(gòu)造 ClientBeatProcessor 對(duì)象
ClientBeatProcessor clientBeatProcessor = new ClientBeatProcessor();
clientBeatProcessor.setService(this);
clientBeatProcessor.setRsInfo(rsInfo);
// 定時(shí)執(zhí)行 ClientBeatProcessor 對(duì)象，這里是立即執(zhí)行，延期時(shí)間為 0
HealthCheckReactor.scheduleNow(clientBeatProcessor);
}ClientBeatProcessor是一個(gè)實(shí)現(xiàn)了Runnable的類，HealthCheckReactor是一個(gè)定時(shí)任務(wù)線程池，scheduleNow方法表示立即執(zhí)行clientBeatProcessor對(duì)象的run方法，clientBeatProcessor.run方法代碼如下，
public void run() {
Service service = this.service;
if (Loggers.EVT_LOG.isDebugEnabled()) {
Loggers.EVT_LOG.debug("[CLIENT-BEAT] processing beat: {}", rsInfo.toString());
}
// 獲取ip
String ip = rsInfo.getIp();
// 獲取 集群名稱
String clusterName = rsInfo.getCluster();
// 獲取端口
int port = rsInfo.getPort();
// 從服務(wù)對(duì)象中獲取集群對(duì)象
Cluster cluster = service.getClusterMap().get(clusterName);
// 從集群對(duì)象中獲取所有的臨時(shí)實(shí)例列表
List<Instance> instances = cluster.allIPs(true);
for (Instance instance : instances) {
// 找到 ip 和端口相同的 實(shí)例數(shù)據(jù)
if (instance.getIp().equals(ip) && instance.getPort() == port) {
if (Loggers.EVT_LOG.isDebugEnabled()) {
Loggers.EVT_LOG.debug("[CLIENT-BEAT] refresh beat: {}", rsInfo.toString());
}
// 更新 最后心跳時(shí)間
instance.setLastBeat(System.currentTimeMillis());
if (!instance.isMarked() && !instance.isHealthy()) {
instance.setHealthy(true);
Loggers.EVT_LOG
.info("service: {} {POS} {IP-ENABLED} valid: {}:{}@{}, region: {}, msg: client beat ok",
cluster.getService().getName(), ip, port, cluster.getName(),
UtilsAndCommons.LOCALHOST_SITE);
getPushService().serviceChanged(service);
}
}
}
}
以上代碼可知，該方法主要用來更新客戶端實(shí)例的最后心跳時(shí)間。
三、服務(wù)端接口
一、定時(shí)檢查服務(wù)實(shí)例任務(wù)
在客戶端注冊(cè)服務(wù)的時(shí)候，會(huì)調(diào)用nacos服務(wù)端的com.alibaba.nacos.naming.controllers.InstanceController#register方法，其中會(huì)調(diào)用createEmptyService方法用來創(chuàng)建空的服務(wù)對(duì)象，最后會(huì)調(diào)用service.init()方法用來初始化服務(wù)對(duì)象，init方法代碼如下
public void init() {
// 定時(shí)執(zhí)行 service 的 run 方法 處理超時(shí)的 instance
HealthCheckReactor.scheduleCheck(clientBeatCheckTask);
for (Map.Entry<String, Cluster> entry : clusterMap.entrySet()) {
entry.getValue().setService(this);
entry.getValue().init();
}
}通過調(diào)用HealthCheckReactor.scheduleCheck()方法來定時(shí)執(zhí)行clientBeatCheckTask，scheduleCheck的代碼如下，
public static void scheduleCheck(ClientBeatCheckTask task) {
// 5秒之后執(zhí)行 task，并且每次執(zhí)行task完之后，5秒之后再次執(zhí)行 task
futureMap.computeIfAbsent(task.taskKey(),
k -> GlobalExecutor.scheduleNamingHealth(task, 5000, 5000, TimeUnit.MILLISECONDS));
}以上代碼給定時(shí)任務(wù)線程池GlobalExecutor提交了一個(gè)task任務(wù)，其中task是一個(gè)實(shí)現(xiàn)了Runable接口的類，線程池每次執(zhí)行的就是ClientBeatCheckTask 的run方法，run方法代碼如下，
public void run() {
try {
if (!getDistroMapper().responsible(service.getName())) {
return;
}
if (!getSwitchDomain().isHealthCheckEnabled()) {
return;
}
// 獲取該服務(wù)下面的所有 注冊(cè)實(shí)例集合
List<Instance> instances = service.allIPs(true);
// first set health status of instances:
for (Instance instance : instances) {
// 如果 當(dāng)前時(shí)間 減去 實(shí)例的最新心跳時(shí)間 如果大于 實(shí)例配置的心跳超時(shí)時(shí)間（默認(rèn)15秒）
// 并且 實(shí)例的健康狀態(tài) true
// 則設(shè)置服務(wù)的健康狀態(tài)為 false
if (System.currentTimeMillis() - instance.getLastBeat() > instance.getInstanceHeartBeatTimeOut()) {
if (!instance.isMarked()) {
if (instance.isHealthy()) {
instance.setHealthy(false);
Loggers.EVT_LOG
.info("{POS} {IP-DISABLED} valid: {}:{}@{}@{}, region: {}, msg: client timeout after {}, last beat: {}",
instance.getIp(), instance.getPort(), instance.getClusterName(),
service.getName(), UtilsAndCommons.LOCALHOST_SITE,
instance.getInstanceHeartBeatTimeOut(), instance.getLastBeat());
getPushService().serviceChanged(service);
ApplicationUtils.publishEvent(new InstanceHeartbeatTimeoutEvent(this, instance));
}
}
}
}
if (!getGlobalConfig().isExpireInstance()) {
return;
}
// then remove obsolete instances:
for (Instance instance : instances) {
if (instance.isMarked()) {
continue;
}
// 如果 當(dāng)前時(shí)間 減去 實(shí)例的最新心跳時(shí)間 如果大于 實(shí)例配置的刪除超時(shí)時(shí)間（默認(rèn)30秒）
// 則會(huì)調(diào)用 deleteIp 刪除方法刪除實(shí)例
if (System.currentTimeMillis() - instance.getLastBeat() > instance.getIpDeleteTimeout()) {
// delete instance
Loggers.SRV_LOG.info("[AUTO-DELETE-IP] service: {}, ip: {}", service.getName(),
JacksonUtils.toJson(instance));
// 刪除實(shí)例
deleteIp(instance);
}
}
} catch (Exception e) {
Loggers.SRV_LOG.warn("Exception while processing client beat time out.", e);
}
}
以上代碼就兩個(gè)邏輯，一個(gè)邏輯是判斷當(dāng)前時(shí)間減去實(shí)例的最新心跳時(shí)間是否大于實(shí)例配置的心跳超時(shí)時(shí)間（默認(rèn)15秒），如果大于則設(shè)置實(shí)例的健康狀態(tài)為false；第二個(gè)邏輯是 判斷當(dāng)前時(shí)間減去實(shí)例的最新心跳時(shí)間 是否大于實(shí)例配置的刪除超時(shí)時(shí)間（默認(rèn)30秒），如果大于則調(diào)用deleteIp(instance);刪除該實(shí)例，deleteIp的代碼如下，
NamingProxy.Request request = NamingProxy.Request.newRequest();
request.appendParam("ip", instance.getIp()).appendParam("port", String.valueOf(instance.getPort()))
.appendParam("ephemeral", "true").appendParam("clusterName", instance.getClusterName())
.appendParam("serviceName", service.getName()).appendParam("namespaceId", service.getNamespaceId());
// 構(gòu)造url地址
String url = "http://" + IPUtil.localHostIP() + IPUtil.IP_PORT_SPLITER + EnvUtil.getPort() + EnvUtil.getContextPath()
+ UtilsAndCommons.NACOS_NAMING_CONTEXT + "/instance?" + request.toUrl();
// delete instance asynchronously:
// 向本地服務(wù)器地址發(fā)送刪除請(qǐng)求
HttpClient.asyncHttpDelete(url, null, null, new Callback<String>() {
@Override
public void onReceive(RestResult<String> result) {
if (!result.ok()) {
Loggers.SRV_LOG
.error("[IP-DEAD] failed to delete ip automatically, ip: {}, caused {}, resp code: {}",
instance.toJson(), result.getMessage(), result.getCode());
}
}
@Override
public void onError(Throwable throwable) {
Loggers.SRV_LOG
.error("[IP-DEAD] failed to delete ip automatically, ip: {}, error: ", instance.toJson(),
throwable);
}
@Override
public void onCancel() {
}
});HttpClient.asyncHttpDelete方法其實(shí)就是向 ${spring.cloud.nacos.discovery.server-addr}/nacos/v1/ns/instance 發(fā)送Delete請(qǐng)求。該請(qǐng)求地址對(duì)應(yīng)的nacos服務(wù)端的源碼的naming工程中InstanceController的deregister方法，deregister代碼如下，
@CanDistro
@DeleteMapping
@Secured(parser = NamingResourceParser.class, action = ActionTypes.WRITE)
public String deregister(HttpServletRequest request) throws Exception {
// 從請(qǐng)求參數(shù)中構(gòu)造實(shí)例對(duì)象
Instance instance = getIpAddress(request);
String namespaceId = WebUtils.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
NamingUtils.checkServiceNameFormat(serviceName);
Service service = serviceManager.getService(namespaceId, serviceName);
if (service == null) {
Loggers.SRV_LOG.warn("remove instance from non-exist service: {}", serviceName);
return "ok";
}
// 刪除實(shí)例數(shù)據(jù)
serviceManager.removeInstance(namespaceId, serviceName, instance.isEphemeral(), instance);
return "ok";
}removeInstance方法是關(guān)鍵，用來刪除實(shí)例數(shù)據(jù)，removeInstance代碼如下，
public void removeInstance(String namespaceId, String serviceName, boolean ephemeral, Instance... ips)
throws NacosException {
// 先獲取服務(wù)對(duì)象
Service service = getService(namespaceId, serviceName);
// 服務(wù)對(duì)象加鎖
synchronized (service) {
// 調(diào)用刪除實(shí)例對(duì)象的方法
removeInstance(namespaceId, serviceName, ephemeral, service, ips);
}
}removeInstance方法的代碼如下，
private void removeInstance(String namespaceId, String serviceName, boolean ephemeral, Service service,
Instance... ips) throws NacosException {
// 構(gòu)造 key
String key = KeyBuilder.buildInstanceListKey(namespaceId, serviceName, ephemeral);
// 獲取服務(wù)下的實(shí)例集合（服務(wù)已有 減去 需要?jiǎng)h除實(shí)例）
List<Instance> instanceList = substractIpAddresses(service, ephemeral, ips);
Instances instances = new Instances();
instances.setInstanceList(instanceList);
// 根據(jù)KEY更新服務(wù)的實(shí)例
consistencyService.put(key, instances);
}substractIpAddresses方法用來獲取該服務(wù)下已經(jīng)減去需要?jiǎng)h除實(shí)例的實(shí)例數(shù)據(jù)，其中調(diào)用的updateIpAddresses方法，action值為 remove。removeInstance方法的整體邏輯為通過updateIpAddresses方法拿到該服務(wù)中去掉刪除實(shí)例之后的實(shí)例集合對(duì)象，并把該實(shí)例集合對(duì)象添加到consistencyService對(duì)象中，consistencyService.put(key, instances)里面的邏輯和客戶端注冊(cè)服務(wù)一樣的邏輯。updateIpAddresses方法和consistencyService.put方法已經(jīng)在客戶端服務(wù)注冊(cè)章節(jié)已經(jīng)講了，這里不再講解。
二、服務(wù)實(shí)例更新推送
在客戶端更新服務(wù)實(shí)例的過程中nacos服務(wù)端會(huì)調(diào)用com.alibaba.nacos.naming.core.Service#updateIPs()方法（客戶端注冊(cè)服務(wù)的過程請(qǐng)看客戶端服務(wù)注冊(cè)章節(jié)），在該方法中會(huì)調(diào)用getPushService().serviceChanged(this)來發(fā)布當(dāng)前服務(wù)的修改事件，即會(huì)發(fā)布一個(gè)事件用來通知已經(jīng)和nacos服務(wù)端通信過的客戶端更新客戶端本地的服務(wù)信息。serviceChanged 的代碼如下，
public void serviceChanged(Service service) {
// merge some change events to reduce the push frequency:
if (futureMap
.containsKey(UtilsAndCommons.assembleFullServiceName(service.getNamespaceId(), service.getName()))) {
return;
}
// 發(fā)布服務(wù)修改事件
this.applicationContext.publishEvent(new ServiceChangeEvent(this, service));
}applicationContext.publishEvent會(huì)觸發(fā)一個(gè)ServiceChangeEvent事件，其實(shí)就是觸發(fā)com.alibaba.nacos.naming.push.PushService#onApplicationEvent方法，其中邏輯為先根據(jù)命名空間id和服務(wù)名稱獲取所有的客戶端map對(duì)象，然后遍歷所有客戶端對(duì)象PushClient 構(gòu)造 ackEntry 對(duì)象，最后向具體的客戶端發(fā)送 upd 消息。獲取關(guān)鍵代碼如下，
if (compressData != null) {
ackEntry = prepareAckEntry(client, compressData, data, lastRefTime);
} else {
// 構(gòu)造 ackEntry 對(duì)象
ackEntry = prepareAckEntry(client, prepareHostsQData(client), lastRefTime);
// 添加緩存
if (ackEntry != null) {
cache.put(key, new org.javatuples.Pair<>(ackEntry.origin.getData(), ackEntry.data));
}
}
Loggers.PUSH.info("serviceName: {} changed, schedule push for: {}, agent: {}, key: {}",
client.getServiceName(), client.getAddrStr(), client.getAgent(),
(ackEntry == null ? null : ackEntry.key));
// 向具體的客戶端發(fā)送 upd 消息
udpPush(ackEntry);以上代碼prepareHostsQData的邏輯就是獲取該服務(wù)下客戶端所屬服務(wù)的所有實(shí)例數(shù)據(jù)，并且構(gòu)造具體的Map<String,Object>對(duì)象，prepareHostsQData代碼如下，
private static Map<String, Object> prepareHostsData(PushClient client) throws Exception {
Map<String, Object> cmd = new HashMap<String, Object>(2);
cmd.put("type", "dom");
// 獲取客戶端所屬服務(wù)的所有實(shí)例數(shù)據(jù)
cmd.put("data", client.getDataSource().getData(client));
return cmd;
}udpPush(ackEntry)里面封裝了發(fā)送udp消息的關(guān)鍵代碼，ackEntry封裝了udp的數(shù)據(jù)信息。
在客戶端獲取服務(wù)實(shí)例列表的時(shí)候，會(huì)生成一個(gè)PushReceiver對(duì)象，該對(duì)象用來監(jiān)聽和接收nacos服務(wù)端發(fā)送的udp數(shù)據(jù)。該對(duì)象實(shí)現(xiàn)了Runnable接口，并且在構(gòu)造方法中把自己提交給了一個(gè)內(nèi)部屬性的線程池對(duì)象。構(gòu)造方法如下，
public PushReceiver(HostReactor hostReactor) {
try {
this.hostReactor = hostReactor;
this.udpSocket = new DatagramSocket();
this.executorService = new ScheduledThreadPoolExecutor(1, new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setDaemon(true);
thread.setName("com.alibaba.nacos.naming.push.receiver");
return thread;
}
});
this.executorService.execute(this);
} catch (Exception e) {
NAMING_LOGGER.error("[NA] init udp socket failed", e);
}
}根據(jù)以上代碼可知，所以在創(chuàng)建PushReceiver對(duì)象之后會(huì)執(zhí)行run方法，run方法的代碼如下，
public void run() {
while (!closed) {
try {
// byte[] is initialized with 0 full filled by default
byte[] buffer = new byte[UDP_MSS];
// 構(gòu)造 DatagramPacket 對(duì)象
DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
// 監(jiān)聽upd數(shù)據(jù)
udpSocket.receive(packet);
// 構(gòu)造服務(wù)對(duì)象的string 數(shù)據(jù)
String json = new String(IoUtils.tryDecompress(packet.getData()), UTF_8).trim();
NAMING_LOGGER.info("received push data: " + json + " from " + packet.getAddress().toString());
PushPacket pushPacket = JacksonUtils.toObj(json, PushPacket.class);
String ack;
if ("dom".equals(pushPacket.type) || "service".equals(pushPacket.type)) {
// 更新本地緩存 serviceInfoMap 的服務(wù)對(duì)象
hostReactor.processServiceJson(pushPacket.data);
// send ack to server
ack = "{\"type\": \"push-ack\"" + ", \"lastRefTime\":\"" + pushPacket.lastRefTime + "\", \"data\":"
+ "\"\"}";
} else if ("dump".equals(pushPacket.type)) {
// dump data to server
ack = "{\"type\": \"dump-ack\"" + ", \"lastRefTime\": \"" + pushPacket.lastRefTime + "\", \"data\":"
+ "\"" + StringUtils.escapeJavaScript(JacksonUtils.toJson(hostReactor.getServiceInfoMap()))
+ "\"}";
} else {
// do nothing send ack only
ack = "{\"type\": \"unknown-ack\"" + ", \"lastRefTime\":\"" + pushPacket.lastRefTime
+ "\", \"data\":" + "\"\"}";
}
udpSocket.send(new DatagramPacket(ack.getBytes(UTF_8), ack.getBytes(UTF_8).length,
packet.getSocketAddress()));
} catch (Exception e) {
if (closed) {
return;
}
NAMING_LOGGER.error("[NA] error while receiving push data", e);
}
}
}
以上代碼用while一直監(jiān)聽udpSocket的客戶端upd的端口。當(dāng)接收到從nacos服務(wù)端發(fā)送過來的udp數(shù)據(jù)之后會(huì)接著調(diào)用 hostReactor.processServiceJson()方法來更新客戶端本地的serviceInfoMap 的服務(wù)對(duì)象。
到此這篇關(guān)于nacos注冊(cè)中心單節(jié)點(diǎn)ap架構(gòu)源碼解析的文章就介紹到這了,更多相關(guān)nacos注冊(cè)中心ap架構(gòu)源碼內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
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