Re: comments on HTTP/1.1 Rev02 20Feb98 (related to caching)

Jeff Mogul wrote:
> One could certainly attack the intellectual basis for the
> discussions (elsewhere) about invalidation.  It's basically
> impossible to do anything "correct", but we've added a few
> stop-gap measures so that in the places where we know what is
> going on, we can avoid obvious incoherencies.  A custom method
> is by definition not part of HTTP/1.1, so it's hard for us to
> specify what it would do to a cache entry, but one could imagine
> implementing a rule that "if you are forwarding a method that
> you don't understand, you should also invalidate any cache
> entries that might possibly be related to the Request-URI."

DMK wrote:
Would it make sense to add words to that effect to the spec.?  Or at
least advice to implementers?

Jeff suggested I propose words.  Here goes.

Add at the end of 13.10, Invalidation After Updates or Deletes:

A cache that passes through requests for methods it does not understand
should invalidate any entities referred to by the Request-URI.

Dave Kristol