当人们将语言从西班牙语更改为其他语言时，我们的软件会使用 cookie “selected_language”。默认情况下未设置 cookie。
我们需要考虑语言来缓存我们的网站，所以我们的 index.php 被缓存了几次，每种语言一个。
我们的哈希函数使用语言 cookie（我们得到了更多的 cookie，但它们在 vcl_recv 中被删除了，只有语言 cookie（如果有的话）进入哈希例程：
sub vcl_hash {
hash_data(req.url);
if (req.http.host) {
hash_data(req.http.host);
} else {
hash_data(server.ip);
}
if (req.http.Cookie) {
hash_data(req.http.Cookie);
}
}
当我们想要清除缓存时，问题就来了。如果我们清除索引网页，不使用 cookie（西班牙语版），一切正常：
curl -X PURGE http://www.arasaac.org/index.php
但是，如果我们尝试使用 cookie（英文版）清除我们的索引网页，它什么也做不了。我认为 purge 使用哈希，所以如果我发送相关的 cookie，它应该可以工作。
我们的清除代码：
sub vcl_purge {
# Only handle actual PURGE HTTP methods, everything else is discarded
if (req.method != "PURGE") {
# restart request
set req.http.X-Purge = "Yes";
return(restart);
}
}
vcl_recv 内部：
# Allow purging
if (req.method == "PURGE") {
# if (!client.ip ~ purge) { # purge is the ACL defined at the begining
# Not from an allowed IP? Then die with an error.
# return (synth(405, "This IP is not allowed to send PURGE requests."));
# }
# If you got this stage (and didn't error out above), purge the cached result
return (purge);
}
这些都是日志，以备不时之需...
我再次询问该页面，该页面已缓存：
* << Request >> 262149
- Begin req 262148 rxreq
- Timestamp Start: 1488455938.456980 0.000000 0.000000
- Timestamp Req: 1488455938.456980 0.000000 0.000000
- ReqStart 172.20.0.3 51672
- ReqMethod GET
- ReqURL /index.php
- ReqProtocol HTTP/1.1
- ReqHeader Host: www.arasaac.org
- ReqHeader Connection: close
- ReqHeader X-Real-IP: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-Proto: http
- ReqHeader X-Forwarded-Ssl: off
- ReqHeader X-Forwarded-Port: 80
- ReqHeader Upgrade-Insecure-Requests: 1
- ReqHeader User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
- ReqHeader Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
- ReqHeader Referer: http://www.arasaac.org/index.php
- ReqHeader Accept-Encoding: gzip, deflate, sdch
- ReqHeader Accept-Language: es-ES,es;q=0.8,en;q=0.6
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqUnset X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1, 172.20.0.3
- VCL_call RECV
- ReqUnset Host: www.arasaac.org
- ReqHeader Host: www.arasaac.org
- ReqURL /
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _ga=GA1.2.99795965.1488449144; _gat=1
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- VCL_return hash
- ReqUnset Accept-Encoding: gzip, deflate, sdch
- ReqHeader Accept-Encoding: gzip
- VCL_call HASH
- VCL_return lookup
- Hit 3
- VCL_call HIT
- VCL_return deliver
- RespProtocol HTTP/1.1
- RespStatus 200
- RespReason OK
- RespHeader Date: Thu, 02 Mar 2017 11:57:52 GMT
- RespHeader Server: Apache/2.4.10 (Debian)
- RespHeader X-Powered-By: PHP/5.6.30
- RespHeader Vary: Accept-Encoding
- RespHeader Content-Encoding: gzip
- RespHeader Content-Length: 5379
- RespHeader Content-Type: text/html; charset=UTF-8
- RespHeader cache-control: public, max-age = 300
- RespHeader log: ha entrado aquí
- RespHeader X-CacheReason: varnishcache
- RespHeader X-Varnish: 262149 3
- RespHeader Age: 66
- RespHeader Via: 1.1 varnish-v4
- VCL_call DELIVER
- RespHeader X-Cache: HIT
- RespHeader X-Cache-Hits: 1
- RespUnset X-Powered-By: PHP/5.6.30
- RespUnset Server: Apache/2.4.10 (Debian)
- RespUnset X-Varnish: 262149 3
- RespUnset Via: 1.1 varnish-v4
- VCL_return deliver
- Timestamp Process: 1488455938.457118 0.000138 0.000138
- RespHeader Accept-Ranges: bytes
- Debug "RES_MODE 2"
- RespHeader Connection: close
- Timestamp Resp: 1488455938.457194 0.000215 0.000077
- ReqAcct 658 0 658 336 5379 5715
- End
我尝试清除页面，所以我发送了 cookie：
curl -X PURGE --cookie "selected_language=en" http://www.arasaac.org/index.php
日志对我来说似乎很好：
* << Request >> 28
- Begin req 27 rxreq
- Timestamp Start: 1488456128.433721 0.000000 0.000000
- Timestamp Req: 1488456128.433721 0.000000 0.000000
- ReqStart 172.20.0.3 53286
- ReqMethod PURGE
- ReqURL /index.php
- ReqProtocol HTTP/1.1
- ReqHeader Host: www.arasaac.org
- ReqHeader Connection: close
- ReqHeader X-Real-IP: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-Proto: http
- ReqHeader X-Forwarded-Ssl: off
- ReqHeader X-Forwarded-Port: 80
- ReqHeader User-Agent: curl/7.35.0
- ReqHeader Accept: */*
- ReqHeader Cookie: selected_language=en;
- ReqUnset X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1, 172.20.0.3
- VCL_call RECV
- ReqUnset Host: www.arasaac.org
- ReqHeader Host: www.arasaac.org
- ReqURL /
- VCL_return purge
- VCL_call HASH
- VCL_return lookup
- VCL_call PURGE
- VCL_return synth
- Timestamp Process: 1488456128.433754 0.000033 0.000033
- RespHeader Date: Thu, 02 Mar 2017 12:02:08 GMT
- RespHeader Server: Varnish
- RespHeader X-Varnish: 28
- RespProtocol HTTP/1.1
- RespStatus 200
- RespReason OK
- RespReason Purged
- VCL_call SYNTH
- VCL_return deliver
- RespHeader Content-Length: 0
- Storage malloc Transient
- RespHeader Accept-Ranges: bytes
- Debug "RES_MODE 2"
- RespHeader Connection: close
- Timestamp Resp: 1488456128.433792 0.000070 0.000038
- ReqAcct 261 0 261 152 0 152
- End
但是，如果我在浏览器中再次加载 index.php，缓存仍然存在：
<< Request >> 30
- Begin req 29 rxreq
- Timestamp Start: 1488456171.661988 0.000000 0.000000
- Timestamp Req: 1488456171.661988 0.000000 0.000000
- ReqStart 172.20.0.3 53688
- ReqMethod GET
- ReqURL /index.php
- ReqProtocol HTTP/1.1
- ReqHeader Host: www.arasaac.org
- ReqHeader Connection: close
- ReqHeader X-Real-IP: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-Proto: http
- ReqHeader X-Forwarded-Ssl: off
- ReqHeader X-Forwarded-Port: 80
- ReqHeader Upgrade-Insecure-Requests: 1
- ReqHeader User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
- ReqHeader Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
- ReqHeader Referer: http://www.arasaac.org/index.php
- ReqHeader Accept-Encoding: gzip, deflate, sdch
- ReqHeader Accept-Language: es-ES,es;q=0.8,en;q=0.6
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqUnset X-Forwarded-For: 172.20.0.1
- ReqHeader X-Forwarded-For: 172.20.0.1, 172.20.0.3
- VCL_call RECV
- ReqUnset Host: www.arasaac.org
- ReqHeader Host: www.arasaac.org
- ReqURL /
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- ReqUnset Cookie: selected_language=en;
- ReqHeader Cookie: selected_language=en;
- VCL_return hash
- ReqUnset Accept-Encoding: gzip, deflate, sdch
- ReqHeader Accept-Encoding: gzip
- VCL_call HASH
- VCL_return lookup
- Hit 3
- VCL_call HIT
- VCL_return deliver
- RespProtocol HTTP/1.1
- RespStatus 200
- RespReason OK
- RespHeader Date: Thu, 02 Mar 2017 11:57:52 GMT
- RespHeader Server: Apache/2.4.10 (Debian)
- RespHeader X-Powered-By: PHP/5.6.30
- RespHeader Vary: Accept-Encoding
- RespHeader Content-Encoding: gzip
- RespHeader Content-Length: 5379
- RespHeader Content-Type: text/html; charset=UTF-8
- RespHeader cache-control: public, max-age = 300
- RespHeader log: ha entrado aquí
- RespHeader X-CacheReason: varnishcache
- RespHeader X-Varnish: 30 3
- RespHeader Age: 299
- RespHeader Via: 1.1 varnish-v4
- VCL_call DELIVER
- RespHeader X-Cache: HIT
- RespHeader X-Cache-Hits: 2
- RespUnset X-Powered-By: PHP/5.6.30
- RespUnset Server: Apache/2.4.10 (Debian)
- RespUnset X-Varnish: 30 3
- RespUnset Via: 1.1 varnish-v4
- VCL_return deliver
- Timestamp Process: 1488456171.662050 0.000061 0.000061
- RespHeader Accept-Ranges: bytes
- Debug "RES_MODE 2"
- RespHeader Connection: close
- Timestamp Resp: 1488456171.662105 0.000117 0.000056
- ReqAcct 658 0 658 337 5379 5716
- End
顺便问一下.. Cookie 相关日志中的 ReqHeader 和 Reqset 行是如何重复多次的？
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqUnset Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1; _ga=GA1.2.99795965.1488449144
- ReqHeader Cookie: PHPSESSID=242b73bc8a560b89308009e05af7eefd; selected_language=en; _gat=1;
...