Re: WGLC: p4, 304 Not Modified

Ken Murchison <murch@andrew.cmu.edu> Mon, 29 April 2013 12:19 UTC

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Date: Mon, 29 Apr 2013 08:18:12 -0400
From: Ken Murchison <murch@andrew.cmu.edu>
Organization: Carnegie Mellon University
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Subject: Re: WGLC: p4, 304 Not Modified
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Any thoughts on this?


Ken Murchison wrote:
> Hi All,
>
> In re-reading the latest section 4.1, I'm wondering why ETag was 
> singled out as being a MUST generate, while Last-Modified isn't.  If 
> the server is capable of generating both, shouldn't it return both, as 
> it SHOULD for 200 responses (per section 2.4)?  What if the client 
> only supports Last-Modified and not ETag (e.g. used If-Modified-Since 
> in its request)?
>
> That being said, if the representation hasn't been modified then 
> presumably none of the validators changed.  What's the point in 
> returning any of them?  Shouldn't it be all or nothing?  Just trying 
> to wrap my head around the logic behind singling out ETag over 
> Last-Modified for 304.
>
-- 
Kenneth Murchison
Principal Systems Software Engineer
Carnegie Mellon University