Problem with varnish and caching

[Anders Berg]

Hi,

> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sat, 30 Jun 2007 19:10:16 -0500
> From: "Manuel Amador (Rudd-O)" <rudd-o at rudd-o.com>
> Subject: Re: Problem with varnish and caching
> To: Dag-Erling Sm?rgrav <des at linpro.no>
> Cc: varnish-misc at projects.linpro.no
> Message-ID: <1183248616.3955.7.camel at gabriela>
> Content-Type: text/plain; charset="utf-8"
> 
> Whether this is part of a different specification or not, it's
> unreasonable for Varnish to NOT cache static, cacheable objects by
> default, solely because these requests were sent along with Cookies.

I am not aware of any HTTP accelerator that would caching this by 
default. Since I believe it is a direct violation of all standards. 
Think of it this way: Why cache pages that are said to be dynamic by the 
webpage.

Squid and Bluecoats will not cache these pages, and the mechanism(s) to 
tune that are far from fine grained.

> In effect, the default Varnish policy of not caching Cookied requests
> causes Varnish not to cache anything at all for most sites (you know,
> there are tons of people out there using Google Analytics).  Think about
> it: why would people want the overhead of a non-caching accelerating
> proxy?

Here you assume "most sites" use Google Analytics. I am not so sure 
about that. Either way, while Varnish will suite almost any site you can 
imagine, it's strengths will be most appreciated by "larger" sites. With 
larger sites I mean sites that would not dream of using Google Analytics.

YS
Anders Berg


> On s?b, 2007-06-30 at 23:41 +0200, Dag-Erling Sm?rgrav wrote:
>> [moved from -dev to -misc]
>>
>> "Manuel Amador (Rudd-O)" <rudd-o at rudd-o.com> writes:
>>> As you might already have noted, I reported a bug on varnish caching
>>> files indiscriminately.
>> This is not a bug, it is a misunderstanding.  It appears you expect
>> Varnish to act like an RFC 2616 "shared cache" whereas it is in fact a
>> "surrogate" (see the "Edge Architecture Specification" by Oracle and
>> Akamai, although Varnish does not yet fully implement that specification
>> either)
>>
>>> My page sets a few cookies.  That'd be okay and it should produce
>>> dynamic pages, which Varnish is furnishing through my backend.  The
>>> thing is, these cookies are sent along requests for CSS and PNG and JPG
>>> and JS files, which causes varnish to contact the backend.  I don't want
>>> that to happen (I'm happy with them being cached by Varnish 120
>>> seconds).
>>>
>>> How can I tell Varnish that requests with a response that includes ETag
>>> (a discriminant for static files) should be forcibly cached?
>> This is basically the same issue as in your previous email, and the
>> answer is the same.
>>
>> DES
> 	Manuel Amador (Rudd-O) <rudd-o at rudd-o.com>
> 	The R Zone - http://rudd-o.com/
> 	GPG key ID 0xC8D28B92 at http://wwwkeys.pgp.net/
> 
> Now playing, courtesy of Amarok: 
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