在做的CDN的机器的http头中,我们常常见到X-Cache和X-Cache-Lookup的二个参数,那这二个参数分别是什么意思,有什么分别啦.
HTTP/1.0 200 OK
Expires: Mon, 23 Jun 2008 09:16:40 GMT
Cache-Control: max-age=60
Content-Type: text/html
Accept-Ranges: bytes
ETag: "985899363"
Last-Modified: Mon, 23 Jun 2008 08:17:40 GMT
Content-Length: 54218
Date: Mon, 23 Jun 2008 09:15:40 GMT
Server: Microsoft-IIS/7.0
Age: 20
X-Cache: HIT from cdcnc-253-238
X-Cache-Lookup: HIT from cdcnc-253-238:80
Via: 1.0 cdcnc-253-238 (squid/3.0.STABLE1-20080201)
Connection: close
见到了吗?很奇怪吧,HIT表示命中,怎么会有二个命中.
X-Cache:其实就个就是真实本机的HIT和MISS.
X-Cache-Lookup:这个就是向父,还有sibling模式的查询,比如ICP.之类命中的数据.