On Thu, 4 Feb 2021 at 11:05, Willy Tarreau <w@1wt.eu> wrote: > On Thu, Feb 04, 2021 at 10:47:13AM +0100, Greg Wilkins wrote: > > I've not yet seen a proposal for using headers that > > addresses the problem of clients that don't know the new headers > mistaking > > the 200 response as valid/complete. > > For me, pre-announcing cache-control in the headers was targetting this > requirement: if you indicate the response is not cacheable until the > final verdict, this is no more a problem. > If the mechanism is only intended to deal with cache-control, then that is probably sufficient. However, I think the use-case of discovering after committing a response that the content is no longer going to be cacheable yet can be completed in a way that is still a valid response for the one request is vanishingly small. Alternatively, if deferred cache-control is only an exemplar of a more general mechanism to signal that metadata fields are expected in the trailer, then I don't think it is sufficient. Something like the 3xx proposal feels safest to avoid accidental interpretation of a 200 response. I know Mark's proposed scope was just cache-control, but it's probably worthwhile at least considering if a more general solution is possible. cheers -- Greg Wilkins <gregw@webtide.com> CTO http://webtide.com
Received on Thursday, 4 February 2021 13:12:11 UTC