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RE: Space Varying URIs in Summary: Section 2: What does a URI id entify?

From: Williams, Stuart <skw@hplb.hpl.hp.com>
Date: Tue, 19 Mar 2002 19:51:47 -0000
Message-ID: <5E13A1874524D411A876006008CD059F192A48@0-mail-1.hpl.hp.com>
To: "'Elliotte Rusty Harold'" <elharo@metalab.unc.edu>
Cc: www-tag@w3.org
Interesting questions...

With respect to caching infrastructure and representations retrived from
cache then I think there's something of a trade-off between degree of global
consistency, latency and scalability. What I think you get is a
representation of the resource you asked for, although it my be a little
stale, and your 'view' of that resource might not be entirely consistent
with the view that you see from elsewhere (or at a different time).

Need to think more about the other case with delayed DNS updates.


> -----Original Message-----
> From: Elliotte Rusty Harold [mailto:elharo@metalab.unc.edu]
> Sent: 19 March 2002 17:25
> To: www-tag@w3.org
> Subject: Space Varying URIs in Summary: Section 2: What does a URI
> identify?
> I notice that this draft makes explicit the idea that a resource is 
> time-varying because wat's at the end of the URI.
> Are resources also space-varying? Consider the impact of proxy 
> servers (especially infrequently updated ones like AOL's), local 
> caches, and even DNS servers that don't always agree with each other. 
> You may not get the same resource I get when resolving the URI 
> http://www.cafeconleche.org/ even if we resolve it at the same moment 
> in time. You may have an older copy in your cache. My DNS may deliver 
> a different mirror site that hasn't been updated yet, etc.
> Does this need to be discussed? Either to confirm it as proper 
> behavior or to deprecate it as indicative of broken software and 
> systems?
> -- 
> +-----------------------+------------------------+-------------------+
> | Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
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> |          The XML Bible, 2nd Edition (Hungry Minds, 2001)           |
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> |   http://www.amazon.com/exec/obidos/ISBN=0764547607/cafeaulaitA/   |
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Received on Tuesday, 19 March 2002 14:52:17 UTC

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