上篇在服務注冊時我們注意到,每個Service執行個體化時會建立一個心跳檢測任務ClientBeatCheckTask:
@Override
public void run() {
try {
if (!getDistroMapper().responsible(service.getName())) {
return;
}
if (!getSwitchDomain().isHealthCheckEnabled()) {
return;
}
// 目前service的所有執行個體
List<Instance> instances = service.allIPs(true);
// first set health status of instances:
for (Instance instance : instances) {
// 超過健康檢查時間
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;
}
// 超過删除檢查時間
if (System.currentTimeMillis() - instance.getLastBeat() > instance.getIpDeleteTimeout()) {
// delete instance
Loggers.SRV_LOG.info("[AUTO-DELETE-IP] service: {}, ip: {}", service.getName(),
JacksonUtils.toJson(instance));
deleteIp(instance);
}
}
} catch (Exception e) {
Loggers.SRV_LOG.warn("Exception while processing client beat time out.", e);
}
}
當發現lastBeat時間過長後就會有相應處理。
那麼當用戶端發送來心跳消息時,我們隻要能看到正常更新lastBeat和狀态即可。
首先是心跳接收的入口方法,InstanceController的beat方法:
@CanDistro
@PutMapping("/beat")
@Secured(parser = NamingResourceParser.class, action = ActionTypes.WRITE)
public ObjectNode beat(HttpServletRequest request) throws Exception {
ObjectNode result = JacksonUtils.createEmptyJsonNode();
//設定要求的心跳間隔 預設5秒
result.put(SwitchEntry.CLIENT_BEAT_INTERVAL, switchDomain.getClientBeatInterval());
String beat = WebUtils.optional(request, "beat", StringUtils.EMPTY);
RsInfo clientBeat = null;
//如果有心跳内容,也就不是輕量級心跳,轉換為RsInfo
if (StringUtils.isNotBlank(beat)) {
clientBeat = JacksonUtils.toObj(beat, RsInfo.class);
}
String clusterName = WebUtils
.optional(request, CommonParams.CLUSTER_NAME, UtilsAndCommons.DEFAULT_CLUSTER_NAME);
String ip = WebUtils.optional(request, "ip", StringUtils.EMPTY);
int port = Integer.parseInt(WebUtils.optional(request, "port", "0"));
if (clientBeat != null) {
if (StringUtils.isNotBlank(clientBeat.getCluster())) {
//擷取叢集名
clusterName = clientBeat.getCluster();
} else {
// fix #2533
clientBeat.setCluster(clusterName);
}
ip = clientBeat.getIp();
port = clientBeat.getPort();
}
String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
String namespaceId = WebUtils.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
Loggers.SRV_LOG.debug("[CLIENT-BEAT] full arguments: beat: {}, serviceName: {}", clientBeat, serviceName);
//擷取相關服務執行個體
Instance instance = serviceManager.getInstance(namespaceId, serviceName, clusterName, ip, port);
//執行個體不存在
if (instance == null) {
//如果心跳内容也沒有就傳回找不到
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);
//否則根據心跳内容建立一個執行個體
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());
//注冊執行個體
serviceManager.registerInstance(namespaceId, serviceName, instance);
}
Service service = serviceManager.getService(namespaceId, serviceName);
// 服務未找到
if (service == null) {
throw new NacosException(NacosException.SERVER_ERROR,
"service not found: " + serviceName + "@" + namespaceId);
}
//不存在的話,要建立一個進行處理
if (clientBeat == null) {
clientBeat = new RsInfo();
clientBeat.setIp(ip);
clientBeat.setPort(port);
clientBeat.setCluster(clusterName);
}
//開啟一次性心跳檢查任務
service.processClientBeat(clientBeat);
//成功傳回,
result.put(CommonParams.CODE, NamingResponseCode.OK);
if (instance.containsMetadata(PreservedMetadataKeys.HEART_BEAT_INTERVAL)) {
//5秒間隔
result.put(SwitchEntry.CLIENT_BEAT_INTERVAL, instance.getInstanceHeartBeatInterval());
}
//告訴用戶端不需要帶上心跳資訊了,變成輕量級心跳了
result.put(SwitchEntry.LIGHT_BEAT_ENABLED, switchDomain.isLightBeatEnabled());
return result;
}
首先如果有beat資訊的話,說明是第一次,這會帶上服務執行個體資訊,進行執行個體注冊。
如果沒有的話,則建立一個用戶端心跳處理器,進行心跳資料處理。 service.processClientBeat(clientBeat):
public void processClientBeat(final RsInfo rsInfo) {
//建立一個臨時心跳處理器,然後排程處理一次。
ClientBeatProcessor clientBeatProcessor = new ClientBeatProcessor();
clientBeatProcessor.setService(this);
clientBeatProcessor.setRsInfo(rsInfo);
HealthCheckReactor.scheduleNow(clientBeatProcessor);
}
我們看一下這個任務的run方法:
@Override
public void run() {
Service service = this.service;
if (Loggers.EVT_LOG.isDebugEnabled()) {
Loggers.EVT_LOG.debug("[CLIENT-BEAT] processing beat: {}", rsInfo.toString());
}
// IP
String ip = rsInfo.getIp();
// 叢集名字
String clusterName = rsInfo.getCluster();
// 端口
int port = rsInfo.getPort();
// 擷取叢集
Cluster cluster = service.getClusterMap().get(clusterName);
// 擷取叢集所有的臨時服務執行個體
List<Instance> instances = cluster.allIPs(true);
// 周遊更新對應的狀态
for (Instance instance : instances) {
// 如果IP和端口一緻則更新
if (instance.getIp().equals(ip) && instance.getPort() == port) {
if (Loggers.EVT_LOG.isDebugEnabled()) {
Loggers.EVT_LOG.debug("[CLIENT-BEAT] refresh beat: {}", rsInfo.toString());
}
//重新整理心跳時間
instance.setLastBeat(System.currentTimeMillis());
//沒被标記的
if (!instance.isMarked()) {
//不健康的
if (!instance.isHealthy()) {
//設定為健康
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);
//發送服務改變事件,PushService實作了 ApplicationListener<ServiceChangeEvent>,事件監聽時發生UDP消息通知
getPushService().serviceChanged(service);
}
}
}
}
}
周遊所有的執行個體,重新整理lastBeat的時間。如果沒有被标記并且健康狀态不對,則設定健康狀态為true,同時發送ServiceChangeEvent事件。
關于PushService實作這個事件的監聽,之前已經分析過了,就是UDP消息通知用戶端。這裡就不再分析了。