Re: [squid-users] How to not cache a site?

Jerome Yanga wrote:
> Thanks for the quick response, Chris.
>
> Here are my attempts to answer your questions. :)
>
>
> Using Live HTTP Headers plugin for Firefox. It seems to show that Cache-Control and Pragma settings.
>
> http://site_address.com/help/jssamples_start.htm
>
> GET /help/jssamples_start.htm HTTP/1.1
> Host: site_address.com
> User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14
> 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
> Connection: keep-alive
> Cookie: CFID=1234567890; CFTOKEN=1234567890; SESSIONID=1234567890; __utma=11111111.111111111.111111111.111111111.111111111.3; __utmc=111111111; __utmz=111111111.111111111.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); __utmb=111111111.4.10. 111111111
>
> HTTP/1.x 200 OK
> Date: Thu, 05 Jun 2008 23:41:00 GMT
> Server: Apache
> Last-Modified: Thu, 05 Jun 2008 09:03:27 GMT
> Etag: "111111111-111111111-111111111"
> Accept-Ranges: bytes
> Content-Type: text/html; charset=UTF-8
> Cache-Control: no-store, no-cache, must-revalidate, max-age=0
> Expires: Thu, 05 Jun 2008 23:41:00 GMT
>

These two lines ("Cache-Control: no-store", and an Expires with the same
time as the request) should stop any (compliant) shared cache from
caching the content. Have you modified the refresh_pattern in your
squid.conf?

> Vary: Accept-Encoding,User-Agent
> Content-Encoding: gzip
> Pragma: no-cache
> Content-Length: 811
> Connection: keep-alive
>
>
> I purge the cache using a purge command.
>
> #file /cache/usr/bin/purge
> /cache/usr/bin/purge: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped
>
> ...and the syntax I use is below.
>
> #/cache/usr/bin/purge -n -v -c /etc/squid/cachepurge.conf -p 127.0.0.1:80 -P 1 -e site_address\.com > /var/log/site_address.com_purge.log
>
> I grep'ed the log created from the command above and I can find instances of site_address.com being deleted. Hence, it is being cached.
>

Have you checked the headers returned with requests for those objects
that are being cached?

> I have also reviewed the access.log and I found a some TCP_MEM_HIT:NONE, TCP_REFRESH_HIT, TCP_IMS_HIT, TCP_HIT, TCP_REFRESH_MISS.
>

Same story here, have you verified the headers on these objects?
Especially the objects that result in TCP_REFRESH_HIT and TCP_IMS_HIT as
(I think) those are requests that are being validated with the origin
server.

> I cannot review the store.log as it is disabled.
>
> I shall try the syntax you have provided on the next available downtime.
>
> acl cacheDenyAclName dstdomain .site_address.com
> acl otherCacheDenyAclName urlpath_regex ^/help/
> cache deny cacheDenyAclName otherCacheDenyAclName
>
> Thanks again, Chris.
>
> Regards,
> Jerome
>

Chris
Received on Fri Jun 06 2008 - 20:58:02 MDT