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Re: Etag-on-write, 2nd attempt (== IETF draft 01)

From: Julian Reschke <julian.reschke@gmx.de>
Date: Thu, 14 Sep 2006 13:31:27 +0200
Message-ID: <45093D8F.7020005@gmx.de>
To: Jamie Lokier <jamie@shareable.org>
CC: Lisa Dusseault <lisa@osafoundation.org>, Helge Hess <helge.hess@opengroupware.org>, HTTP Working Group <ietf-http-wg@w3.org>, Jonathan Rosenberg <jdrosen@cisco.com>

Jamie Lokier schrieb:
> Julian Reschke wrote:
>> Lisa Dusseault schrieb:
>>>> That's incorrect, at least as the Xythos client is concerned (see 
>>>> <http://lists.w3.org/Archives/Public/ietf-http-wg/2006AprJun/0090.html>).
>>>>
>>> I can't really see how we disagree here.  If the server returns a strong 
>>> ETag, the Xythos client assumes that the content was written as sent.  
>>> Later, when the client attempts to refresh its cache, if the ETag is 
>>> still the same, the client happily continues using the entity that it 
>>> PUT.   Thus, a user can refresh and refresh and refresh, and still not 
>>> see quite what the server has stored and other clients/users see.
>> Yes, but if the server *doesn't* return an ETag (as mandated by CalDAV), 
>> it simply uses the Last-Modified time stamp again. That is, it doesn't 
>> work at all with servers rewriting the content upon PUT, no matter 
>> whether they return an ETag or not.
> 
> But why not a weak Etag, along with "Cache-Control:
> max-age=0,must-revalidate"?  (Or "proxy-revalidate" if you don't mind
> _that particular_ client reusing the sent entity).

RFC2616 says that weak etags can't be used with PUT/If-Match. So of what 
use would that be?

Best regards, Julian
Received on Thursday, 14 September 2006 11:31:34 GMT

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