Nacos - 客户端注册中提到了心跳续约。
public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException { String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName); if (instance.isEphemeral()) { // 封装心跳信息 BeatInfo beatInfo = beatReactor.buildBeatInfo(groupedServiceName, instance); // 开启定时工作续约 beatReactor.addBeatInfo(groupedServiceName, beatInfo); } serverProxy.registerService(groupedServiceName, groupName, instance);}BeatReactor#addBeatInfo
把心跳工作放入线程池。
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 // 移除旧的BeatInfo if ((existBeat = dom2Beat.remove(key)) != null) { existBeat.setStopped(true); } //存入dom2Beat dom2Beat.put(key, beatInfo); // 开启定时工作 executorService.schedule(new BeatTask(beatInfo), beatInfo.getPeriod(), TimeUnit.MILLISECONDS); MetricsMonitor.getDom2BeatSizeMonitor().set(dom2Beat.size());}BeatReactor.BeatTask#run
向服务器发送心跳，如果没有心跳信息，则从新注册。
public void run() { if (beatInfo.isStopped()) { return; } long nextTime = beatInfo.getPeriod(); try { // 向服务器发送心跳 JsonNode result = serverProxy.sendBeat(beatInfo, BeatReactor.this.lightBeatEnabled); // 获取下一次发送的间隔时间 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(); } // 发现没有心跳信息，则从新注册 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()); } executorService.schedule(new BeatTask(beatInfo), nextTime, TimeUnit.MILLISECONDS); }