Subject: #167: Content-Location on 304 responses

From: Mark Nottingham <[email-masked]>
Date: Mon, 24 Aug 2009 13:44:58 +1000

<http://trac.tools.ietf.org/wg/httpbis/trac/ticket/167>

p6 2.4 Validation Model says:
> If a cache receives a successful response whose Content-Location  
> field matches that of an existing stored response for the same  
> Request-URI, whose entity-tag differs from that of the existing  
> stored response, and whose Date is more recent than that of the  
> existing response, the existing response SHOULD NOT be returned in  
> response to future requests and SHOULD be deleted from the cache.  
> [[anchor6: DISCUSS: Not sure if this is necessary.]]
The proposal is to remove this paragraph, because Content-Location- 
based selection isn't widely implemented.

Note that there's also discussion of adding more text to clarify when  
cached responses need to be replaced/update.

--
Mark Nottingham     http://www.mnot.net/

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From: Julian Reschke <[email-masked]>
Date: Sun, 30 Aug 2009 10:52:34 +0200

Mark Nottingham wrote:
>> If a cache receives a successful response whose Content-Location field 
>> matches that of an existing stored response for the same Request-URI, 
>> whose entity-tag differs from that of the existing stored response, 
>> and whose Date is more recent than that of the existing response, the 
>> existing response SHOULD NOT be returned in response to future 
>> requests and SHOULD be deleted from the cache. [[anchor6: DISCUSS: Not 
>> sure if this is necessary.]]
> The proposal is to remove this paragraph, because Content-Location-based 
> selection isn't widely implemented.
> 
> ...

Proposed patch: 
<http://trac.tools.ietf.org/wg/httpbis/trac/attachment/ticket/167/167.diff>.

Question: does this need to be mentioned as change from RFC2616?

BR, Julian

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From: Mark Nottingham <[email-masked]>
Date: Mon, 31 Aug 2009 17:23:45 +1000

I think so.

On 30/08/2009, at 6:52 PM, Julian Reschke wrote:

>> Note that there's also discussion of adding more text to clarify  
>> when cached responses need to be replaced/update.
>> ...
>
> Proposed patch: <http://trac.tools.ietf.org/wg/httpbis/trac/attachment/ticket/167/167.diff 
> >.
>

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From: Julian Reschke <[email-masked]>
Date: Mon, 31 Aug 2009 14:59:15 +0200

> I think so.

OK, I came up with:

-- snip --
  Removed requirement to consider Content-Location in successful
  responses in order to invalidate cached responses.
  (<xref target="validation.model" />)
-- snip --

Is that sufficiently accurate?

BR, Julian

---

From: Mark Nottingham <[email-masked]>
Date: Tue, 1 Sep 2009 13:04:25 +1000

No, this isn't about invalidation, it's about determining the  
appropriate response to use.