Question

我在varnish-3.0.5服务器前运行Apache/2.4.10实例。两者都在同一台Ubuntu 12.04.4机器上。 Varnish服务器随机将一些请求转发到后端服务器，即使它已经在缓存中有页面。

当我做一个简单的请求时：

GET http://www.example.com/
Accept: */*
Accept-Encoding: gzip, deflate
Host: www.example.com
User-Agent: runscope/0.1

我有时会从缓存中收到正确的回复：

Accept-Ranges: bytes
Age: 5973
Cache-Control: private, no-cache, no-store, must-revalidate
Connection: keep-alive
Content-Encoding: gzip
Content-Length: 10015
Content-Type: text/html; charset=utf-8
Date: Fri, 24 Oct 2014 15:26:35 GMT
Expires: -1
Last-Modified: Fri, 24 Oct 2014 13:47:02 GMT
Server: Apache
Vary: Accept-Encoding
Via: 1.1 varnish
X-Varnish: 10531909 10507062

有时（更经常地）直接来自Apache的回复：

Cache-Control: no-cache
Connection: keep-alive
Content-Encoding: gzip
Content-Length: 10015
Content-Type: text/html; charset=utf-8
Date: Fri, 24 Oct 2014 15:28:00 GMT
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified: Fri, 24 Oct 2014 15:28:00 GMT
Server: Apache
Set-Cookie: [truncated]
Vary: Accept-Encoding

我确定该项目仍然在缓存中，因为在直接来自Apache的几个响应后，我收到了Varnish的响应，其中Age标题包含的数字高于上一个答案的数字。清漆。

我的VCL文件：

# Default backend definition.  Set this to point to your content server.
backend default {
    .host = "127.0.0.1";
    .port = "8080";
}

# List of IPs allowed to erase things from cache
acl purge {
        "localhost";
        "127.0.0.1"/8;
}

sub vcl_recv {
     # Purge item from the cache
      if (req.request == "PURGE") {
        if (!client.ip ~ purge) {
            error 405 "Not allowed.";
        }

        return (lookup);
     }

       # Setting Forwarding header
     if (req.restarts == 0) {
        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;
        }
     }

       ## Pipeline ajax requests except of requests for [truncated]
     if (req.http.X-Requested-With == "XMLHttpRequest" && req.url !~ "^/[truncated]") {
       return(pipe);
     }

     if (req.request != "GET" &&
       req.request != "HEAD" &&
       req.request != "PUT" &&
       req.request != "POST" &&
       req.request != "TRACE" &&
       req.request != "OPTIONS" &&
       req.request != "DELETE") {
         /* Non-RFC2616 or CONNECT which is weird. */
         return (pipe);
     }
     if (req.request != "GET" && req.request != "HEAD") {
         /* We only deal with GET and HEAD by default */
         return (pass);
     }

     ## Remove GCLID param from googles adds
     set req.url = regsuball(req.url,"\?gclid=[^&]+$",""); # strips when QS = "?gclid=AAA"
     set req.url = regsuball(req.url,"\?gclid=[^&]+&","?"); # strips when QS = "?gclid=AAA&foo=bar"
     set req.url = regsuball(req.url,"&gclid=[^&]+",""); # strips when QS = "?foo=bar&gclid=AAA" or QS = "?foo=bar&gclid=AAA&bar=baz"

### always cache these items:

     ## JavaScript
     if (req.request == "GET" && req.url ~ "\.(js)") {
         return (lookup);
     }

       ## images
     if (req.request == "GET" && req.url ~ "\.(gif|jpg|jpeg|bmp|png|tiff|tif|ico|img|tga|wmf)$") {
        return (lookup);
     }

       ## various other content pages   
       if (req.request == "GET" && req.url ~ "\.(css|html)$") { 
        return (lookup);
     }      

     ## multimedia 
     if (req.request == "GET" && req.url ~ "\.(svg|swf|ico|mp3|mp4|m4a|ogg|mov|avi|wmv)$") {
        return (lookup);
     }  

       ## xml
     if (req.request == "GET" && req.url ~ "\.(xml)$") {
        return (lookup);
     }

     ## Do not cache POST requests 
     if (req.request == "POST") {
         return (pipe);
     }    

     ## Do not cache the [truncated]
     if (req.url ~ "^/[truncated]") {
         return (pipe);
     }

     ## Cache the [truncated]
     if (req.url ~ "^/[truncated]") {
         return (lookup);
     }

     ## Cache the [truncated]
     if (req.url ~ "^/[truncated]") {
         return (lookup);
     }

     ## Do not cache the [truncated]
     if (req.url ~ "^/[truncated]") {
         return (pipe);
     }

     ## Exceptions for [truncated]
     if (req.url ~ "^/[truncated]") {
         return (pass);
     }

     ## Exceptions for [truncated]
     if (req.url ~ "^/[truncated]") {
         return (pipe);
     }

     return (lookup);
}

sub vcl_hash {

    hash_data(req.url);
    if (req.http.host) {
        hash_data(req.http.host);
    } else {
        hash_data(server.ip);
    }

    ## Make a request to check the logged in status of the current user
    if (req.request == "GET" && req.url !~ "\.(js|css|html|gif|jpg|jpeg|bmp|png|tiff|tif|ico|img|tga|wmf|svg|swf|ico|mp3|mp4|m4a|ogg|mov|avi|wmv|xml)$" && req.http.cookie ~ "cache-logged-in=1") {
        hash_data("logged-in");
    }

    return (hash);
}

#
sub vcl_hit {
    if (req.request == "PURGE") {
        purge;
        error 200 "Purged.";
    }

    return (deliver);
}

#
sub vcl_miss {
    if (req.request == "PURGE") {
        purge;
        error 200 "Purged.";
    }

    return (fetch);
}

#
sub vcl_fetch {  

 ## If the request to the backend returns a code other than 200, restart the loop
 ## If the number of restarts reaches the value of the parameter max_restarts,
 ## the request will be error'ed.  max_restarts defaults to 4.  This prevents
 ## an eternal loop in the event that, e.g., the object does not exist at all.
 ## this rule also allows for 301's and 302's redirects...

    ## Unset cookies sent from the backend if they are not necessary
    if (req.url ~ "[truncated]")) {
        if (beresp.http.set-cookie !~ "cache-logged-in") {
            unset beresp.http.set-cookie;
        }
    }     

      if (beresp.status != 200 && beresp.status != 403 && beresp.status != 404 && beresp.status != 301 && beresp.status != 302 && beresp.status != 303) {
        return (restart);
    }

    # if I cant connect to the backend, ill set the grace period to be 7200 seconds to hold onto content
    set beresp.ttl = 7200s;
    set beresp.grace = 7200s;

    # If the header X-nocache is present, do not cache the item
    if (beresp.http.x-nocache) {
        return (hit_for_pass);
    }

    if (beresp.status == 404) { 
        set beresp.ttl = 0s; 
    }

    if (beresp.status >= 500) { 
        set beresp.ttl = 0s; 
    }

    if (req.request == "GET" && req.url ~ "\.(gif|jpg|jpeg|bmp|png|tiff|tif|ico|img|tga|wmf)$") {
        set beresp.ttl = 86400s;     
    }
    else if (req.request == "GET" && req.url ~ "\.(css|html)$") {
        ## various other content pages
        set beresp.ttl = 86400s;
    }
    else if (req.request == "GET" && req.url ~ "\.(js)$") {
        set beresp.ttl = 86400s;
    }
    else if (req.request == "GET" && req.url ~ "\.(xml)$") {
        set beresp.ttl = 86400s;
    }
    else if (req.request == "GET" && req.url ~ "\.(svg|swf|ico|mp3|mp4|m4a|ogg|mov|avi|wmv)$") {
        ## multimedia
        set beresp.ttl = 86400s;
    }
    else {
        set beresp.http.Expires = "-1";
        set beresp.http.Cache-Control = "private, no-cache, no-store, must-revalidate";
    }


    return(deliver); 
}

Answer 1

转发到apache的请求与已经在varnish中的请求不同，这就是简单的解释。至于它们的不同之处，您需要查看完整请求的多个选项，但可能包括： - cookies（请注意，apache请求正在设置cookie，以便我可以在哪里开始）。 - url大小写的区别（你的哈希区分大小写）。

Answer 2

在vcl_recv中取消设置req.http.cookie。

清漆随机转发请求到后端

2 个答案: