服务续约

服务续约的线程和Eureka - 服务发现中的一样，这里不再解说，咱们间接通过HeartbeatThread的run办法看renew办法。

boolean renew() {    EurekaHttpResponse<InstanceInfo> httpResponse;    try {        // 调用EurekaServer地址+"apps/" + appName + '/' + id        httpResponse = eurekaTransport.registrationClient.sendHeartBeat(instanceInfo.getAppName(), instanceInfo.getId(), instanceInfo, null);        logger.debug(PREFIX + "{} - Heartbeat status: {}", appPathIdentifier, httpResponse.getStatusCode());        if (httpResponse.getStatusCode() == Status.NOT_FOUND.getStatusCode()) {            REREGISTER_COUNTER.increment();            logger.info(PREFIX + "{} - Re-registering apps/{}", appPathIdentifier, instanceInfo.getAppName());            long timestamp = instanceInfo.setIsDirtyWithTime();            boolean success = register();            if (success) {                instanceInfo.unsetIsDirty(timestamp);            }            return success;        }        return httpResponse.getStatusCode() == Status.OK.getStatusCode();    } catch (Throwable e) {        logger.error(PREFIX + "{} - was unable to send heartbeat!", appPathIdentifier, e);        return false;    }}

服务注册

在Eureka - Client服务启动中提到initScheduledTasks中会调用InstanceInfoReplicator#start办法。

public void start(int initialDelayMs) {    if (started.compareAndSet(false, true)) {        instanceInfo.setIsDirty();  // for initial register        Future next = scheduler.schedule(this, initialDelayMs, TimeUnit.SECONDS);        scheduledPeriodicRef.set(next);    }}

start办法会启动一个定时工作，就会调用InstanceInfoReplicator#run办法。refreshInstanceInfo会刷新数据中心信息和租约信息。

public void run() {    try {        // 刷新数据中心信息和租约信息。        discoveryClient.refreshInstanceInfo();        Long dirtyTimestamp = instanceInfo.isDirtyWithTime();        // 如果信息有变动，则注册        if (dirtyTimestamp != null) {            // 注册,"apps/" + info.getAppName()            discoveryClient.register();            instanceInfo.unsetIsDirty(dirtyTimestamp);        }    } catch (Throwable t) {        logger.warn("There was a problem with the instance info replicator", t);    } finally {        // 线程用于刷新信息以及从新注册        Future next = scheduler.schedule(this, replicationIntervalSeconds, TimeUnit.SECONDS);        scheduledPeriodicRef.set(next);    }}

完结

直至，服务注册、服务发现、服务续约，client局部曾经讲完了。