> Apache Shiro™ is a powerful and easy-to-use Java security framework that performs authentication, authorization, cryptography, and session management. With Shiro’s easy-to-understand API, you can quickly and easily secure any application – from the smallest mobile applications to the largest web and enterprise applications.
Spring Cloud Netflix 的微服务都是以 HTTP 接口的形式暴露的，所以可以用 Apache 的 HttpClient 或 Spring 的 RestTemplate 去调用，而 Feign 是一个使用起来更加方便的 HTTP 客戶端，使用起来就像是调用自身工程的方法，而感觉不到是调用远程方法。
*[GitHub](https://github.com/OpenFeign/feign)
### 服务熔断
> 作用: 当请求到达一定阈值时不让请求继续.
#### Hystrix
* > Hystrix is a latency and fault tolerance library designed to isolate points of access to remote systems, services and 3rd party libraries, stop cascading failure and enable resilience in complex distributed systems where failure is inevitable.
> Hystrix is a latency and fault tolerance library designed to isolate points of access to remote systems, services and 3rd party libraries, stop cascading failure and enable resilience in complex distributed systems where failure is inevitable.
