Re: Fwd: draft-ietf-http-v11-spec-rev-04 comments
Roy T. Fielding (fielding@kiwi.ics.uci.edu)
Thu, 10 Sep 1998 10:41:19 -0700
>I'm inclined to agree with Roy, with the following additional caveat:
>please define "upstream" and "downstream". They always confuse me and,
>I suspect, others. Please don't say "it's obvious". I don't know
>whether requests flow upstream or downstream.
Upstream and downstream are flow, i.e., all messages flow from upstream
to downstream.
There aren't that many occurrences of any of these terms, but the
distinction can be important. For example, in section 13.11 we have
All methods that might be expected to cause modifications to the origin
server's resources MUST be written through to the origin server. This
currently includes all methods except for GET and HEAD. A cache MUST NOT
reply to such a request from a client before having transmitted the
request to the inbound server, and having received a corresponding
response from the inbound server. This does not prevent a proxy cache
from sending a 100 (Continue) response before the inbound server has
sent its final reply.
where the term "inbound server" is used to refer to first the downstream
server and then the upstream server in the same sentence, since they
are the same thing when the first mention is for the request and the
second for the response.
Likewise, the use of "upstream" in the definition of Via is useful
to indicate the bidirectionality of that header field.
....Roy