我在 Ubuntu 11.10 上的 Apache 2 前面设置了一个 Varnish。我正在使用这个 VCL 文件：
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
if (req.url ~ "^/web") {
unset req.http.cookie;
}
if (req.url ~ "administration" ||
req.url ~ "preview"
) {
return(pass);
}
if (req.http.Cookie) {
set req.http.Cookie = ";"+req.http.Cookie;
set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
set req.http.Cookie = regsuball(req.http.Cookie, ";(mag_header)=", "; \1=");
set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
if (req.http.Cookie == "") {
remove req.http.Cookie;
}
}
if (req.url ~ "\.(html|gif|jpg|jpeg|png|js|css)$") {
unset req.http.cookie;
return(lookup);
}
if (req.http.x-forwarded-for) {
set req.http.X-Forwarded-For =
req.http.X-Forwarded-For + ", " + client.ip;
}
else {
set req.http.X-Forwarded-For = client.ip;
}
if (req.http.x-forwarded-host) {
set req.http.X-Forwarded-Host =
req.http.X-Forwarded-Host + ", " + server.ip;
}
else {
set req.http.X-Forwarded-Host = server.ip;
}
return(lookup);
}
sub vcl_hash {
hash_data(req.http.cookie);
}
sub vcl_fetch {
set beresp.ttl =30m;
}
mag_header cookie 的值只能是三个值中的一个，从而将缓存的变体数量降到最低。不过，我看到主页上有很多未命中的情况（大约每 60 秒 7 次），而这些应该缓存 30 分钟。
知道为什么它不缓存吗？
欢呼吧，马克
编辑
下面是对主页发出的请求（不幸的是，我不确定这是否是我的问题的一个很好的例子，如果我应该抓取另一个，请告诉我）：
29 RxHeader c User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11
29 RxHeader c Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
29 RxHeader c Referer: http://www.vmagazine.com/site/content/451/the-discreet-charm-of-kate-upton
29 RxHeader c Accept-Encoding: gzip,deflate,sdch
29 RxHeader c Accept-Language: en-US,en;q=0.8
29 RxHeader c Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
29 RxHeader c Cookie: vmag_header=vmag; __utma=232335640.704196202.1357394712.1357394712.1357394712.1; __utmb=232335640.25.10.1357394712; __utmc=232335640; __utmz=232335640.1357394712.1.1.utmcsr=popwatch.ew.com|utmccn=(referral)|utmcmd=referral|utmcct=/2013/01/04/krist
29 VCL_call c recv lookup
29 VCL_call c hash
29 Hash c vmag_header=vmag
29 Hash c /
29 Hash c www.vmagazine.com
29 VCL_return c hash
29 HitPass c 1682448674
29 VCL_call c pass pass
29 Backend c 19 default default
29 TTL c 1682448965 RFC 120 -1 -1 1357394808 0 1357394807 0 0
29 VCL_call c fetch
29 TTL c 1682448965 VCL 1800 -1 -1 1357394808 -0
29 TTL c 1682448965 VCL 120 -1 -1 1357394808 -0
29 VCL_return c hit_for_pass
29 ObjProtocol c HTTP/1.1
29 ObjResponse c OK
29 ObjHeader c Date: Sat, 05 Jan 2013 14:06:47 GMT
29 ObjHeader c Server: Apache/2.2.20 (Ubuntu)
29 ObjHeader c X-Powered-By: PHP/5.3.6-13ubuntu3.9
29 ObjHeader c Set-Cookie: vmag_header=vmag; path=/
29 ObjHeader c Vary: Accept-Encoding
29 ObjHeader c Content-Encoding: gzip
29 ObjHeader c Content-Length: 16315
29 ObjHeader c Content-Type: text/html
29 ObjHeader c X-Pad: avoid browser bug
29 Gzip c u F - 16315 77445 80 80 130452
29 VCL_call c deliver deliver
29 TxProtocol c HTTP/1.1
29 TxStatus c 200
29 TxResponse c OK
29 TxHeader c Server: Apache/2.2.20 (Ubuntu)
29 TxHeader c X-Powered-By: PHP/5.3.6-13ubuntu3.9
29 TxHeader c Set-Cookie: vmag_header=vmag; path=/
29 TxHeader c Vary: Accept-Encoding
29 TxHeader c Content-Encoding: gzip
29 TxHeader c Content-Type: text/html
29 TxHeader c X-Pad: avoid browser bug
29 TxHeader c Content-Length: 16315
29 TxHeader c Accept-Ranges: bytes
29 TxHeader c Date: Sat, 05 Jan 2013 14:06:47 GMT
29 TxHeader c X-Varnish: 1682448965
29 TxHeader c Age: 0
29 TxHeader c Via: 1.1 varnish
29 TxHeader c Connection: keep-alive
29 Length c 16315
29 ReqEnd c 1682448965 1357394807.567663431 1357394807.963178158 0.000065088 0.395375967 0.000138760
答案1
问题是我的代码中有一个 session_start() 调用，它添加了一个 PHP_SESSION cookie，这意味着缓存从未命中。