Exponential backoffIn 中文意义为【指数退避】。wiki上是这么介绍的： Exponential backoff is an algorithm that uses feedback to multiplicatively decrease the rate of some process, in order to gradually find an acceptable rate. These algorithms find usage in a wide range of systems and processes, with radio networks and computer networks being particularly notable. 大致意思是说指数退避是一种常见于无线电网络和计算机网络的的算法。是通过反馈乘法降低某些过程的速率，以逐渐找到可接受的速率的一种算法。 粗糙的理解就是网络请求响应要遵纪守法，请求失败和重试之间要有指数间隔，不要无节制地请求把别人的服务搞崩了。 我为啥要写这篇文章呢？下面是一则【旧闻】，长图警告： <img src="http://product.liyiru.top/uploads/111.jpg" />