Re: [squid-users] AVG Updates not being cached with squid 2.6?

Amos Jeffries wrote:
> Richard Chapman wrote:
>> I have a more or less default configured squid 2.6 proxy on a centos
>> 5.4 server.
>> I have configured AVG 9 network edition (Virus scanner) to use the
>> squid proxy (as opposed to the avg proxy) - and it appears to be
>> doing so.
>> However - checking the usage logs - it appears that different client
>> machines download identical update (.bin) files within a few hours of
>> each other - but do not appear to get a cache hit..
>>
>> Can anyone suggest why these update files are not being cached (or at
>> least not getting cache hits) - and whether there is anything I can
>> do to encourage them to be cached?
>>
>> I have checked the Squid FAQ and searched the archive - and found a
>> similar request from 2005. The suggestion there was that the AVG
>> server might be using the
>>
>> "Pragma: no-cache" HTTP header
>
> To be sure take the URL that should be a HIT and enter it at redbot.org.
> The whole problems should be easily visible there.
>
>>
>> And that at that time there was no suggestion on how to override
>> this. Can anyone confirm that this is the reason for the apparently
>> unnecessary cache misses - and if so - is there anything new in squid
>> to allow us to override?
>>
>
> Squid which do not ignore "Pragma: no-cache" treat it the same as
> "Cache-Control: no-cache"
>
> Amos
Thanks Amos
I tried redbot as you suggested - and this is a url which I think SHOULD
have been a hit - though it is hard to be sure. The stats show that NONE
of the avg updates come from cache - and I assume they should all have
similar headers... Hopefully someone more knowledgeable than I can make
more sense of this;

http://redbot.org/?uri=http://aa.avg.com/softw/90/update/u7iavi2551u2550qp.bin

It looks to me that it should be cacheable - but the only suspicious
thing is the statement I get when I hover over the "This response is
stale". I think it says that it has a "Freshnes lifetime of 0" - which
sounds like it will always be considered stale. I'm not sure why they
would do this as each update has a unique file name - and could
therefore be considered fresh indefinitely couldn't it?

Can anyone confirm my interpretation - and/or suggest a way to treat the
updates more rationally?

Richard.

A cache considers a HTTP response stale when its age (here, 0) is equal
to or exceeds its freshness lifetime (in this case, 0)

A A cache considers a HTTP response stale when its age (here, 0) is
equal to or exceeds its freshness lifetime (in this case, 0).cache
considers a HTTP response stale when its age (here, 0) is equal to or
exceeds its freshness lifetime (in this case, 0).
Received on Tue Dec 08 2009 - 09:10:17 MST