Re: [squid-users] Trying to cache no-cache objects

> Hello to list,
>
> I have a requirement to cache non-cachable objects. I have tried on my
> own, googled a lot but could not able to do. Can any body help me to
> achieve this, please. I know that this is against the HTTP policy, but i
> have to do it. Many people have done this i think in squid.

Yes, many have. Which is one reason the www still logs people into the
wrong bank accounts, email boxes etc. Security means nothing when its
turned off.

Whoever gave you that 'MUST' needs a good kick.

>
> squid 3.0.7STABLE's squid.conf
>
> refresh_pattern ^ftp: 1440 20% 10080
> refresh_pattern ^gopher: 1440 0% 1440
> refresh_pattern (cgi-bin|\?) 999999 100% 999999 override-expire
> override-lastmod ignore-no-store ignore-reload ignore-no-cache
> ignore-private
> refresh_pattern -i
> \.(html|php|asp|dll|htm|aspx|mspx|shtml|cgi|php3|jse|phtml|po|pl|fcgi|jsp|py|php4|text|txt|js)$
> 999999 100% 999999 ignore-reload ignore-no-cache ignore-no-store
> ignore-private ignore-auth
>
> refresh_pattern -i (cam|kam|live|stream).*\.(gif|jpeg|jpg)(\?.*|)$ 999999
> 100% 999999 override-expire override-lastmod ignore-reload
> ignore-no-cache ignore-no-store ignore-private ignore-auth
>
> refresh_pattern -i \.(gif|jpeg|jpg|swf|png|bmp|pic)$ 999999 100% 999999
> override-expire override-lastmod ignore-reload ignore-no-cache
> ignore-no-store ignore-private ignore-auth
>
> refresh_pattern -i \.(js|css|class|jar|xml|txt|cfm|doc|xls|pdf)$ 999999
> 100% 999999 override-expire override-lastmod ignore-reload
> ignore-no-cache ignore-no-store ignore-private ignore-auth
>
> refresh_pattern -i \.(exe|gz|tar|tgz|zip|arj|ace|bin|cab|msi)(\?.*|)$
> 999999 100% 999999 override-expire override-lastmod ignore-reload
> ignore-no-cache ignore-no-store ignore-private ignore-auth
>
> refresh_pattern -i \.(mid|mp[234]|wav|ram|rm|au)(\?.*|)$ 999999 100%
> 999999 override-expire override-lastmod ignore-no-store ignore-reload
> ignore-no-cache ignore-private ignore-auth
>
> refresh_pattern -i \.(mpg|mpeg|avi|asf|wmv|wma)(\?.*|)$ 999999 100%
> 999999 override-expire override-lastmod ignore-no-store ignore-reload
> ignore-no-cache ignore-private ignore-auth
>
> refresh_pattern . 999999 100% 999999 override-expire override-lastmod
> ignore-reload ignore-no-cache ignore-no-store ignore-private
> ignore-auth

Most of those refresh patterns are duplicates and causing much slowdown
being processed on every request. This last pattern '.' by itself can
replace all of your file type patterns.

>
> And the header of the page to which i am trying to cache is
> Set-Cookie: sessioncookie=f8336e8eb4726523f2f8be76cb7f9be8; expires=Thu,
> 31 Jul 2008 01:02:46 GMT; path=/
> Expires: Mon, 26 Jul 1997 05:00:00 GMT
> Last-Modified: Wed, 30 Jul 2008 13:02:47 GMT
> Cache-Control: no-store, no-cache, must-revalidate
> Cache-Control: post-check=0, pre-check=0
> Pragma: no-cache
>
> When i am accessing this page, in access log i got
>
> 1217419381.382 1284 192.168.99.23 TCP_REFRESH_MODIFIED/200
>
> It means that the page is not in the cache. Please help me i will be very
> thankful to you all.

No. It means the object was in cache but squid obeyed the
'must-revalidate' (usually only used on authenticated pages).
The page itself HAD changed between the last storage time and the new
request so the server sent a new one. Changing is normal for no-cache
objects, that is why they are no-cache (ie. "don't bother wasting disk
resources").
In normal web traffic that would be a TCP_MISS.

I really, really, really, hope your squid is not being used with humans on
the client-side. That caching model is one major disaster waiting to
happen.

Amos
Received on Thu Jul 31 2008 - 04:19:11 MDT