Varnish 在刷新期间服务旧对象

Question

如何在获取过期对象或 max 期间提供旧对象 输出连接？

我已将 vcl_recv 中的宽限期配置为 vcl_fetch。

我什至尝试使用圣人模式来还给我一个“旧”缓存对象。

有人可以在这件事上给我帮助吗？

sub vcl_recv {

# Purge through http
if (req.request == "PURGE") {
if (!client.ip ~ purge) {
error 405 "Not allowed.";
}
ban("req.url ~ " + req.url );
error 200 "Purged.";
}

# Unset all cookies available
if (req.http.cookie) {
unset req.http.cookie;
}

if (req.request != "GET" && req.request != "HEAD") {
/* We only deal with GET and HEAD by default */
return (pass);
}

# Adding Grace period in case backend lags
set req.grace = 3d;
return (lookup);
}
....
sub vcl_fetch {
set beresp.grace = 4d;
set beresp.saintmode = 50s;
set beresp.ttl = 30s;
return (deliver);
}

#### 缓存请求 varnishlog

0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"
11 SessionOpen  c XXX.XXX.XXX.XXX 60750 XXX.XXX.XXX.XXX:2002
11 ReqStart     c XXX.XXX.XXX.XXX 60750 479090107
11 RxRequest    c GET
11 RxURL        c /image/1156499/1601812475/45010cb14311wq1fd2da042ed599f3ad917005085c400/1181_615/crop
11 RxProtocol   c HTTP/1.0
11 RxHeader     c Host: URL
11 RxHeader     c X-Real-IP: XXX.XXX.XXX.XXX
11 RxHeader     c X-Forwarded-For: XXX.XXX.XXX.XXX
11 RxHeader     c Connection: close
11 RxHeader     c User-Agent: GraphicalHttpClient 1.0.6 (Macintosh; Mac OS X 10.6.8; en_NL)
11 VCL_call     c recv lookup
11 VCL_call     c hash
11 Hash         c /image/1156499/1601812475/45010cb14311wq1fd2da042ed599f3ad917005085c400/1181_615/crop
11 Hash         c URL
11 VCL_return   c hash
11 Hit          c 479090015
11 VCL_call     c hit deliver
11 VCL_call     c deliver deliver
11 TxProtocol   c HTTP/1.1
11 TxStatus     c 200
11 TxResponse   c OK
11 TxHeader     c Server: nginx/1.0.11
11 TxHeader     c Content-Type: image/jpeg
11 TxHeader     c Content-Transfer-Encoding: binary
11 TxHeader     c Cache-Control: must-revalidate
11 TxHeader     c Content-Length: 125395
11 TxHeader     c Accept-Ranges: bytes
11 TxHeader     c Date: Tue, 07 Feb 2012 14:23:00 GMT
11 TxHeader     c X-Varnish: 479090107 479090015
11 TxHeader     c Age: 5693
11 TxHeader     c Via: 1.1 varnish
11 TxHeader     c Connection: close
11 Length       c 125395
11 ReqEnd       c 479090107 1328624580.355833769 1328624580.357449532 0.000084162 0.000103474 0.001512289
11 SessionClose c Connection: close
11 StatSess     c XXX.XXX.XXX.XXX 60750 0 1 1 0 0 0 29

#### 缓存请求过期的 Varnishlog

12 BackendOpen  b live XXX.XXX.XXX.XXX 41945 XXX.XXX.XXX.XXX 80
12 TxRequest    b GET
12 TxURL        b /image/1156499/1601812475/45010cb14311wq1fd2da042ed599f3ad917005085c400/1181_615/crop
12 TxProtocol   b HTTP/1.1
12 TxHeader     b Host: URL
12 TxHeader     b X-Real-IP: XXX.XXX.XXX.XXX
12 TxHeader     b X-Forwarded-For: XXX.XXX.XXX.XXX
12 TxHeader     b User-Agent: GraphicalHttpClient 1.0.6 (Macintosh; Mac OS X 10.6.8; en_NL)
12 TxHeader     b X-Varnish: 479090118
12 TxHeader     b Accept-Encoding: gzip
12 RxProtocol   b HTTP/1.1
12 RxStatus     b 200
12 RxResponse   b OK
12 RxHeader     b Server: nginx/1.0.11
12 RxHeader     b Date: Tue, 07 Feb 2012 14:26:00 GMT
12 RxHeader     b Content-Type: image/jpeg
12 RxHeader     b Connection: keep-alive
12 RxHeader     b Content-Transfer-Encoding: binary
12 RxHeader     b Cache-Control: must-revalidate
12 RxHeader     b Content-Length: 125395
12 Fetch_Body   b 4(length) cls 0 mklen 1
12 Length       b 125395
12 BackendReuse b live
11 SessionOpen  c XXX.XXX.XXX.XXX 50429 XXX.XXX.XXX.XXX:2002
11 ReqStart     c XXX.XXX.XXX.XXX 50429 479090118
11 RxRequest    c GET
11 RxURL        c /image/1156499/1601812475/45010cb14311wq1fd2da042ed599f3ad917005085c400/1181_615/crop
11 RxProtocol   c HTTP/1.0
11 RxHeader     c Host: URL
11 RxHeader     c X-Real-IP: XXX.XXX.XXX.XXX
11 RxHeader     c X-Forwarded-For: XXX.XXX.XXX.XXX
11 RxHeader     c Connection: close
11 RxHeader     c User-Agent: GraphicalHttpClient 1.0.6 (Macintosh; Mac OS X 10.6.8; en_NL)
11 VCL_call     c recv lookup
11 VCL_call     c hash
11 Hash         c /image/1156499/1601812475/45010cb14311wq1fd2da042ed599f3ad917005085c400/1181_615/crop
11 Hash         c URL
11 VCL_return   c hash
11 VCL_call     c miss fetch
11 Backend      c 12 live live
11 TTL          c 479090118 RFC 120 -1 -1 1328624761 0 1328624760 0 0
11 VCL_call     c fetch
11 TTL          c 479090118 VCL 33 -1 -1 1328624758 -3
11 TTL          c 479090118 VCL 33 40 -1 1328624758 -3
11 VCL_return   c deliver
11 ObjProtocol  c HTTP/1.1
11 ObjResponse  c OK
11 ObjHeader    c Server: nginx/1.0.11
11 ObjHeader    c Date: Tue, 07 Feb 2012 14:26:00 GMT
11 ObjHeader    c Content-Type: image/jpeg
11 ObjHeader    c Content-Transfer-Encoding: binary
11 ObjHeader    c Cache-Control: must-revalidate
11 VCL_call     c deliver deliver
11 TxProtocol   c HTTP/1.1
11 TxStatus     c 200
11 TxResponse   c OK
11 TxHeader     c Server: nginx/1.0.11
11 TxHeader     c Content-Type: image/jpeg
11 TxHeader     c Content-Transfer-Encoding: binary
11 TxHeader     c Cache-Control: must-revalidate
11 TxHeader     c Content-Length: 125395
11 TxHeader     c Accept-Ranges: bytes
11 TxHeader     c Date: Tue, 07 Feb 2012 14:26:00 GMT
11 TxHeader     c X-Varnish: 479090118
11 TxHeader     c Age: 0
11 TxHeader     c Via: 1.1 varnish
11 TxHeader     c Connection: close
11 Length       c 125395
11 ReqEnd       c 479090118 1328624757.532856941 1328624760.899299860 0.000095606 3.364968061 0.001474857
11 SessionClose c Connection: close
11 StatSess     c XXX.XXX.XXX.XXX 50429 3 1 1 0 0 1 284 125395
0 Debug        - "lurker: 0x7f244cfd1e00 30 0"

Answer 1

这是一个有趣的问题。

来自文档

When several clients are requesting the same page Varnish will send one request to the backend and place the others on hold while fetching one copy from the back end.

因此，即使您启用了宽限，在任何时间点都会有一个客户端被阻止。 Grace 通知 Varnish，您可以为所有其他 n-1 客户提供过时的内容，直到第一个人回来提供一些内容进行刷新。没有办法解除对那个家伙的阻止[技术上异步获取是不可能的]

看看这个漂亮的article我认为您真正要求的是我希望下一个版本的计划功能