Re: First draft of a list of goals

In message <9512210316.AA03574@acetes.pa.dec.com>, Jeffrey Mogul writes:
>
>(2) Correctness comes before performance.  

Amen.

>(2a) The protocol must ALLOW correct caching, in which the user is
>guaranteed to see a valid copy of an object unless some network failure
>prevents it.

Hmm... this begs the question of what's valid, which can only
be answered by a spec or model. I agree with the goal in
principal, but we'll have to see what the model looks like.

There's also a question of terminology. To be consistent with
the HTTP spec, I'd say "valid entity representing a resource"
rather than "valid copy of an object." In order to have
an effective discussion, this is pretty important.

>(2b) The protocol must ALLOW users, servers, and proxies to choose
>performance over correctness if they want to, but must not force
>them to do so.

Hmm... that's not the way I'd word it, but I think I agree.
What you're saying is that in some cases, you'll get something
different from a caching proxy than what you would have gotten
by going to the origin server, and that's OK. I think the
thing to do is to define correctness in such away that this
is part of the deal, not to allow proxies to be "incorrect"
with respect to the protocol we make up.

Dan

Received on Wednesday, 20 December 1995 20:27:11 UTC