Re: New Version Notification for draft-nottingham-cache-header-00.txt

[Kazuho Oku <[e-mail]>]

Hi Mark,

Thank you for the draft.

I like the Cache header it because it standardizes what we have been
doing, and it has clear structure that can be used by the client to
collect stats.

OTOH, I wonder how we should use it in conjunction with Server-Timing header.

In my view, both the Cache header and the Server-Timing header allows
caches and intermediaries to set arbitrary information related to
processing.

For example, I think the example described in the I-D (quoted below
using separate Cache header for each element) can be represented also
by using the Server-Timing headers as show below.

    Cache: HIT_FRESH; node="reverse-proxy.example.com:80";
        key="https://example.com/foo|Accept-Encoding:gzip"
    Cache: HIT_STALE; node="FooCDN parent"; fresh=-45; age=200; latency=3,
    Cache: MISS; node="FooCDN edge"; fresh=-45; age=200; latency=98

    Server-Timing: hit-fresh; node="reverse-proxy.example.com:80";
        key="https://example.com/foo|Accept-Encoding:gzip"
    Server-Timing: hit-stale; node="FooCDN parent"; fresh=-45; age=200; dur=3
    Server-Timing: miss; node="FooCDN edge"; fresh=-45; age=200; dur=98

I do not think that having both Cache and Server-Timing is a bad idea.
However I would like to see a clarification on how they should be
used, especially because their features are IMO overlapping
(especially the `latency` and `dur` attributes).

2018年9月7日(金) 15:48 Mark Nottingham <[e-mail]>:
>
> FYI; IMO it's past time to standardise x-cache and have a real spec for it.
>
> This is a straw-man, based on a bit of research on existing implementations.
>
> Pretty version at:
>   https://mnot.github.io/I-D/cache-header/
>
> Comments? I think the primary audience here is proxy cache and CDN vendors, and their users.
>
> Cheers,
>
>
>
> Begin forwarded message:
>
> From: [e-mail]
> Subject: New Version Notification for draft-nottingham-cache-header-00.txt
> Date: 7 September 2018 at 4:41:52 pm AEST
> To: "Mark Nottingham" <[e-mail]>
>
>
> A new version of I-D, draft-nottingham-cache-header-00.txt
> has been successfully submitted by Mark Nottingham and posted to the
> IETF repository.
>
> Name: draft-nottingham-cache-header
> Revision: 00
> Title: The Cache HTTP Response Header
> Document date: 2018-09-07
> Group: Individual Submission
> Pages: 7
> URL:            https://www.ietf.org/internet-drafts/draft-nottingham-cache-header-00.txt
> Status:         https://datatracker.ietf.org/doc/draft-nottingham-cache-header/
> Htmlized:       https://tools.ietf.org/html/draft-nottingham-cache-header-00
> Htmlized:       https://datatracker.ietf.org/doc/html/draft-nottingham-cache-header
>
>
> Abstract:
>   To aid debugging, HTTP caches often append headers to a response
>   detailing how they handled the request.  This specification codifies
>   that practice and updates it for HTTP's current caching model.
>
>
>
>
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
>
> The IETF Secretariat
>
>
> --
> Mark Nottingham   https://www.mnot.net/
>


-- 
Kazuho Oku