Re: Why should caches and intermediaries ignore If-Match?

Alex Rousskov <rousskov@measurement-factory.com> Fri, 17 February 2017 22:18 UTC

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Cc: Tom Bergan <tombergan@chromium.org>
To: HTTP Working Group <ietf-http-wg@w3.org>
From: Alex Rousskov <rousskov@measurement-factory.com>
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Date: Fri, 17 Feb 2017 15:15:36 -0700
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Subject: Re: Why should caches and intermediaries ignore If-Match?
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On 02/17/2017 03:06 PM, Tom Bergan wrote:
> On Thu, Feb 16, 2017 at 5:21 PM, Alex Rousskov wrote:
>     On 02/15/2017 04:43 PM, Tom Bergan wrote:
>     > if the cache does not have an allowed ETag, then the
>     > request should be forwarded to the origin. Does that sound right?


>     It sounds reasonable to me but it would violate the original RFC 2616
>     text and go against the letter (but perhaps not the intent) of the new
>     HTTPbis rules.


> I don't think it would violate the original RFC 2616 text?


AFAICT, it would violate the following RFC 2616 Section 14.24 MUST:

>    If none of the entity tags match [...]
>    the server [...]
>    MUST return a 412 (Precondition Failed) response.

A [caching] proxy is a server.

Alex.