先来个流程图：

Title:反向代理示范图
client->proxy:GET / http/1.1
Note right of proxy:代理过程不可见
proxy-->server:GET / http/1.1
server-->proxy:200 OK
proxy->client:200 OK

dateFormat YYYY-MM-DD
section S1
T1: 2014-01-01, 9d
section S2
T2: 2014-01-11, 9d
section S3
T3: 2014-01-02, 9d