Re: [squid-users] acl problem with mime types

Andrew Pounce wrote:
> Chris Robertson wrote:
>
>> Andrew Pounce wrote:
>>
>>> Hi,
>>>
>>> I have a website which uses squid as an accelerator that serves content
>>> as a series of numbers such as /12345/12345/12345/12345 which can be
>>> images, html or pretty much anything else.
>>>
>>> Some of the html varies depending on status of the user session ( are
>>> they authenticated etc )
>>>
>>>
>> If the user is authenticated, the server is likely sending out a
>> "Cache-Control: private" header.
>>
>
> The authentication is handled by the app rather than standard http-auth
> which is one of the reason's that I'm attempting to cache particular
> parts of the site rather than all of it which would be much easier.
>
>
>>> I want to :-
>>>
>>> Cache ALL images.
>>> not cache ALL html.
>>>
>>> now I my understanding of things I can check the mime type with acl's
>>> and cache allow/cache deny :-
>>>
>>> acl imagesmime rep_mime_type image/jpeg
>>> acl imagesmime1 rep_mime_type -i image/jpeg
>>> cache allow imagesmime
>>> cache allow imagesmime1
>>> cache deny all
>>>
>>> I keep seeing TCP_MISS's for images dispite this, the mime type
>>> image/jpeg ( according to the access.log ) so I don't understand whats
>>> going on - am I missing something obvious?
>>>
>>>
>
> Having used the firefox live headers tool I see pretty much what the
> squid logs were telling me :-
> http://www.xxxxx.xxx:8080/1242167/2184304
>
> GET /1242167/2184304 HTTP/1.1
> Host: www.xxxxx.xxx:8080
> User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1)
> Gecko/20060601 Firefox/2.0.0.1 (Ubuntu-edgy)
> Accept:
> text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
> Accept-Language: en-us,en;q=0.5
> Accept-Encoding: gzip,deflate
> Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
> Keep-Alive: 300
> Proxy-Connection: keep-alive
> Cookie: balancer=TC1; JSESSIONID=blah
>
> HTTP/1.x 200 OK
> Cache-Control: s-maxage=8477, max-age=0
>

I'm not an expert, but I think this would be your problem. From
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html:

> When the max-age cache-control directive is present in a cached
> response, the response is stale if its current age is greater than the
> age value given (in seconds) at the time of a new request for that
> resource.
and

> If a response includes both an Expires header and a max-age directive,
> the max-age directive overrides the Expires header, even if the
> Expires header is more restrictive.

s-maxage is a HTTP 1.1 construct (if I'm not mistaken), and Squid is not
1.1 compliant. So you are saying this content is always stale.

> Etag: 1.4
> Expires: Mon, 29 Jan 2007 12:48:45 GMT
> Last-Modified: Fri, 11 Aug 2006 12:48:45 GMT
> Content-Type: image/jpeg
> Content-Length: 25586
> Date: Mon, 29 Jan 2007 10:27:27 GMT
> Server: Apache-Coyote/1.1
> X-Cache: MISS from proxya
> X-Cache-Lookup: MISS from proxya:3128
> Via: 1.0 proxya:3128 (squid/2.6.STABLE1)
> Proxy-Connection: keep-alive
> ----------------------------------------------------------
>
> I don't get this as I thought that the rep_mime_type should catch this..
>
> Thanks,
>
> -Andrew
>
>

Chris
Received on Mon Jan 29 2007 - 18:33:04 MST