Spring Cloud Eureka 源码跟踪(3.服务续约)

通过定时线程类（ScheduledExecutorService scheduler）间隔renewalIntervalInSecs（默认30s）执行DiscoveryClient.HeartbeatThread方法获取服务。

this.scheduler.schedule(new TimedSupervisorTask(“heartbeat”, this.scheduler, this.heartbeatExecutor, renewalIntervalInSecs, TimeUnit.SECONDS, expBackOffBound, new DiscoveryClient.HeartbeatThread()), (long)renewalIntervalInSecs, TimeUnit.SECONDS);

HeartbeatThread run内容

this.eurekaTransport.registrationClient.sendHeartBeat 向服务器发送心跳