【原创】Eureka源码剖析之六：自我保护机制

synchronized (lock) {
    if (this.expectedNumberOfClientsSendingRenews > 0) {
        // Since the client wants to register it, increase the number of clients sending renews
        // 期望客户端发送续约数增1
        this.expectedNumberOfClientsSendingRenews = this.expectedNumberOfClientsSendingRenews + 1;
        // 更新每分钟续约阈值
        updateRenewsPerMinThreshold();
    }
}


// 更新每分钟续约阈值：期望客户端续约数*2(60/30秒默认)*百分比（0.85），即每分钟续约数量
protected void updateRenewsPerMinThreshold() {
    this.numberOfRenewsPerMinThreshold = (int) (this.expectedNumberOfClientsSendingRenews
            * (60.0 / serverConfig.getExpectedClientRenewalIntervalSeconds())
            * serverConfig.getRenewalPercentThreshold());
}

synchronized (lock) {
       if (this.expectedNumberOfClientsSendingRenews > 0) {
           // Since the client wants to cancel it, reduce the number of clients to send renews
           // 期望客户端发送续约数减1
           this.expectedNumberOfClientsSendingRenews = this.expectedNumberOfClientsSendingRenews - 1;
           // 更新每分钟续约阈值
           updateRenewsPerMinThreshold();
       }
   }