- From: Willy Tarreau <w@1wt.eu>
- Date: Thu, 31 Mar 2022 09:07:09 +0200
- To: Glenn Strauss <gs-lists-ietf-http-wg@gluelogic.com>
- Cc: HTTP Working Group <ietf-http-wg@w3.org>, kazuhooku@gmail.com, lucaspardue.24.7@gmail.com
Hello Glenn, On Thu, Mar 31, 2022 at 01:21:42AM -0400, Glenn Strauss wrote: > Comments on Extensible Prioritization Scheme for HTTP > https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-priority-12 > > HTTP/2 SETTINGS frame in the original RFC7540 spec contains > SETTINGS_ENABLE_PUSH > This is a logical, boolean flag to enable an optional-use feature. > > draft-ietf-httpbis-priority-12 has had multiple revisions with name > changes for a new setting, and the current proposed name is > SETTINGS_NO_RFC7540_PRIORITIES > with an *inverted boolean value*, which if set to *true* results in > indicating a desire to *disable* use of RFC7540 HTTP/2 PRIORITY frame. It's not as much a desire to "disable" as it is an indication that it will neither emit nor process them. > I am a developer mocking up draft-ietf-httpbis-priority. > From my perspective, in order to follow a logical opt-in to enable use > of optional features, I prefer the following proposal: new SETTINGS > SETTINGS_ENABLE_PRIORITY > SETTINGS_ENABLE_PRIORITY_UPDATE > each named after the respective HTTP/2 frame type PRIORITY > and (proposed) PRIORITY_UPDATE. These are named in similar pattern to > SETTINGS_ENABLE_PUSH feature, associated with HTTP/2 frame PUSH_PROMISE. But that wouldn't work with existing deployments! Right now support for priorities is implied by H2. Both a client and a server willing to use them have nothing to say, and any RFC7540-compliant implementation will see it like this. Thus a client may expect that the server will deliver important objects first and may possibly announce certain priorities based on what it thinks it needs. In fact both sides may act in a way that is supposed to help the other one based on the assumption that it will use it and benefit from this. Explicitly saying "no need to make efforts for me" and "I will not bother you with this" can be a useful indication to the partner that it ought to fall back to alternate mechanisms instead. Hoping this helps, Willy
Received on Thursday, 31 March 2022 07:07:32 UTC