清漆请求丢失缓存，尽管在

Question

我在 Varnish 缓存中有这个请求：

ReqMethod      GET
ReqURL         /organisation/xyz/proposal_0000000/comments/comment_0000001/

然后将一些 PURGE 请求发送到 Varnish，从而生成以下禁令列表：

ban.list 200 2108
Present bans: 1458150360.937187 16 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/team0000000$ 1458150360.929092 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz$ 1458150360.926030 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/pitch0000000$ 1458150360.923491 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/practicalrelevance0000000$ 1458150360.921025 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/plan0000000$ 1458150360.918480 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/target0000000$ 1458150360.915931 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/duration0000000$ 1458150360.913486 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/difference0000000$ 1458150360.910710 0 - req.http.host == localhost:8088 && req.url ~ /$ 1458150360.908150 0 - req.http.host == localhost:8088 && req.url ~ /organisation$ 1458150360.906249 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/extrainfo0000000$ 1458150360.904289 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/connectioncohesion0000000$ 1458150360.901930 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/challenge0000000$ 1458150360.899287 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/goal0000000$ 1458150360.896989 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/partners0000000$ 1458150360.894324 0 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000$ 1458150360.891701 0 C
1458150348.035639 1 C

然后再次执行相同的 GET 请求，但有一个 MISS：

* << Request >> 32790
- Begin req 32789 rxreq - Timestamp Start: 1458150371.759282 0.000000 0.000000 - Timestamp Req: 1458150371.759282 0.000000 0.000000 - ReqStart 127.0.0.1 43526 - ReqMethod GET - ReqURL /organisation/xyz/proposal_0000000/comments/comment_0000001/ - ReqProtocol HTTP/1.1 - ReqHeader Host: localhost:8088 - ReqHeader Connection: keep-alive - ReqHeader Pragma: no-cache - ReqHeader Cache-Control: no-cache - ReqHeader Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 - ReqHeader Upgrade-Insecure-Requests: 1 - ReqHeader Referer: http://localhost:8088/organisation/xyz/proposal_0000000/comments/?elements=paths - ReqHeader Accept-Encoding: gzip, deflate, sdch - ReqHeader Accept-Language: en-GB,en-US;q=0.8,en;q=0.6 - ReqHeader X-Forwarded-For: 127.0.0.1 - VCL_call RECV - VCL_return hash - ReqUnset Accept-Encoding: gzip, deflate, sdch - ReqHeader Accept-Encoding: gzip - VCL_call HASH - VCL_return lookup - ExpBan 3 banned lookup - VCL_call MISS - VCL_return fetch - Link bereq 32791 fetch - Timestamp Fetch: 1458150371.779571 0.020289 0.020289 - RespProtocol HTTP/1.1 - RespStatus 200 - RespReason OK - RespHeader Server: gunicorn/19.2.1 - RespHeader Date: Wed, 16 Mar 2016 17:46:11 GMT - RespHeader X-Caching-Mode: with_proxy_cache - RespHeader X-Caching-Strategy: HTTPCacheStrategyWeakAdapter - RespHeader Cache-Control: max-age=0, proxy-revalidate, s-maxage=31104000 - RespHeader Vary: Accept-Encoding, X-User-Path, X-User-Token - RespHeader Content-Type: application/json; charset=UTF-8 - RespHeader Access-Control-Allow-Origin: * - RespHeader Access-Control-Allow-Methods: POST,GET,DELETE,PUT,OPTIONS - RespHeader Access-Control-Allow-Headers: Origin, Content-Type, Accept, X-User-Path, X-User-Token - RespHeader ETag: W/"0|1|2016-03-16 13:44:05.887212+00:00|None|None" - RespHeader Content-Encoding: gzip - RespHeader X-Varnish: 32790 - RespHeader Age: 0 - RespHeader Via: 1.1 varnish-v4 - VCL_call DELIVER - VCL_return deliver - Timestamp Process: 1458150371.779598 0.020317 0.000028 - RespHeader Accept-Ranges: bytes - RespHeader Content-Length: 426 - Debug "RES_MODE 2" - RespHeader Connection: keep-alive - Timestamp Resp: 1458150371.779641 0.020359 0.000042 - ReqAcct 598 0 598 699 426 1125 - End

然后是禁止列表：

ban.list 200 147
Present bans: 1458150360.937187 17 - req.http.host == localhost:8088 && req.url ~ /organisation/xyz/proposal_0000000/team0000000$

我知道正则表达式。 /organisation/xyz/proposal_0000000/comments/comment_0000001/ 如何匹配ban.list 中的任何模式？这没有意义。

我正在使用 Varnish 4.1.1

Answer 1

与您的网址匹配的规则是：

1458150360.910710     0 -  req.http.host == localhost:8088 && req.url ~ /$

regex req.url ~ /$ 将匹配您的 URL 以及任何其他以斜杠结尾的 URL；使用 req.url ~ ^/$。

一些观察：

• 您应该使用“==”直接比较，因为您知道完整的 URL https://www.varnish-cache.org/docs/3.0/reference/varnish-cli.html#ban-expressions
• 使用 varnishtest 调试复杂情况
• 尝试对潜伏者友好

关于对潜伏者友好的禁令表达

阅读更多here

对潜伏者友好的禁令表达式是那些只使用 obj. 而不是 req. 变量的表达式。由于对 lurker 友好的禁令表达式缺少 req.，您可能需要将一些 req. 内容复制到 obj 结构中。实际上，这种复制操作是一种将客户端请求的上下文保存在缓存对象中的机制。例如，您可能希望将客户端上下文的有用部分，例如请求的 URL 从 req 复制到 obj。

下面的 sn-p 显示了如何在缓存对象中保留客户端请求的上下文的示例：

sub vcl_backend_response {
   set beresp.http.x-url = bereq.url;
}

sub vcl_deliver {
   # The X-Url header is for internal use only
   unset resp.http.x-url;
}

正则表达式的清漆测试示例：

您可以使用以下命令运行它：varnishtest test_regex.vtc

test_regex.vtc 内容：

# act like a backend server
server s1 {
    rxreq
    txresp
    expect req.url == "/organisation/xyz/proposal_0000000/comments/comment_0000001/"
    expect req.http.Test == "dosent_match" 
} -start

# define & start a varnish instance
varnish v1 -vcl {
    backend default {
    .host = "${s1_addr}";
    .port = "${s1_port}";
    }

    sub vcl_recv {
    if ( req.url ~ "/$" ) {
        set req.http.Test="match";
    } else {
        set req.http.Test="dosent_match";
    }
  }

} -start

# make a client request
client c1 { 

    txreq -url "/organisation/xyz/proposal_0000000/comments/comment_0000001/"
    rxresp

} -run

varnish v1 -expect client_req == 1