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

From: bijayant kumar <bijayant4u_at_yahoo.com>
Date: Wed, 30 Jul 2008 21:53:22 -0700 (PDT)

Hi,

Thanks for your reply and pointing out some basic thing about the policies. I will try to explain the same to the my people who want this settings. One thing is clear from your reply that i am able to cache the no-cache objects, right. One point you have mentioned that "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." This point i did not understand, what does it mean? I apologise to asking this question.

Thanks & Regards

Bijayant Kumar

--- On Thu, 31/7/08, Amos Jeffries <squid3_at_treenet.co.nz> wrote:

> From: Amos Jeffries <squid3_at_treenet.co.nz>
> Subject: Re: [squid-users] Trying to cache no-cache objects
> To: bijayant4u_at_yahoo.com
> Cc: "squid users" <squid-users_at_squid-cache.org>
> Date: Thursday, 31 July, 2008, 9:48 AM
> > 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 Send instant messages to your online friends http://uk.messenger.yahoo.com
Received on Thu Jul 31 2008 - 04:53:34 MDT

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