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Re: querystring part of cache key

From: David Morris <dwm@xpasc.com>
Date: Fri, 22 May 2009 09:39:40 -0700 (PDT)
To: Jamie Lokier <jamie@shareable.org>
cc: Adrien de Croy <adrien@qbik.com>, HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <Pine.LNX.4.64.0905220936520.18015@egate.xpasc.com>


On Fri, 22 May 2009, Jamie Lokier wrote:

> Adrien de Croy wrote:
>>
>> there were discussions recently about the method being part of the cache
>> key, since the response for different methods on the same URI could
>> presumably be cacheable and different.
>>
>> What about query string?  If the result to something that has a
>> querystring is marked as cachable by the origin server, then is it
>> deemed part of the URI for the cache key?  I'd presume yes.
>
> Of coures, the query string is just part of the URI.
>
>> Since URIs can be arbitrarily long, yet database fields aren't good with
>> this, I'd presume it's common practise to look up based on some hash
>> value.  Is this approach used?  Is there any industry-standard hashing
>> method, e.g. MD5 of method+URI(normalised) + querystring ?
>
> I doubt it.  Why would you do that?  I don't think it's normal to use
> a URI to select an application and pass the querystring verbatim to a
> database, or at least it's not a good idea :-)

Why not? .. this is a caching related question where the URI is part of
the cache key ... since I've not implemented such a cache, I can't speak 
to what I have done, but a hash such as MD5 seems reasonable ... in 
particular if followed by an exact match comparison with a value stored
in a blob, etc.
Received on Friday, 22 May 2009 16:40:25 GMT

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