Re: Draft functional requirements (strawman or woodman, you decide!)

David G. Durand (dgd@cs.bu.edu)
Thu, 18 Jul 1996 11:53:02 -0400


At 12:55 PM 7/2/96, Larry Masinter wrote:
>Most of these are OK, but "Stableness of versions" is a repository
>requirement, not a protocol requirement. We might want to call out
>some protocol requirement where a client can DETERMINE whether the
>repository supports stable versions independent of other kinds of
>modifications.

  It seems to me that the desire that a versioned URL be stable is
inherent to the notion of versioning, and can be a protocol requirement
(ie. assumption that users of the protocol are entitled to make). However,
since URLs are not guaranteed to be stable, we still have a problem,
because if the base URL is re-used, the versions should obviously not have
to be persistent. Perhaps we can simply say "If the document addressed by a
base URL (we don't have a proper name for this concept) remains the same,
then the versions of that document will be stable.

   I think this is important, as a stability guaranteee (even a weak one)
allows versioning to be used to provide intelligent caching, distribution,
and so on. And a server implementer is free to strengthen the guarantee if
they want to, by not re-using base URLs.

----------------------------------------------+----------------------------
  David Durand                 dgd@cs.bu.edu  | david@dynamicDiagrams.com
  Boston University Computer Science          | Dynamic Diagrams
  http://cs-www.bu.edu:80/students/grads/dgd/ | http://dynamicDiagrams.com/