- From: Jeff Bone <jbone@jump.net>
- Date: Sun, 31 Mar 2002 11:56:47 -0600
- To: LMM@acm.org
- CC: www-tag@w3.org
Larry Masinter wrote: > # You could argue that the implied contract here is outside the scope of > # the architecture, but at some point there is a *need* to represent a > # given resource with a particular set of bits, if only for reification > # so you can discuss the properties of that representation. > > HTTP uses ETag for this, specifically so that caching can be managed. But ETags don't really fully solve the problem, do they? This stems from the ambiguity in the relationships between resources, representations, and the bits that one gets back in response to an HTTP request. ETags interact badly with things like range requests, compression, delta encoding, etc. Does the ETag relate to the baf-of-bits received in such a case, or the potentially reconstructed "snapshot" / representation of resource state that can be built from several of these things? Mogul's recent preprint [1] IMO does a good job both of elaborating the problem and presenting a model and mechanisms to address it. jb [1] http://www.research.compaq.com/wrl/people/mogul/www2002/mogulwww2002preprint.pdf
Received on Sunday, 31 March 2002 12:59:05 UTC