Re: [quicwg/base-drafts] Lessen the divergence from the HTTP/2 prioritization scheme by requiring all PRIORITY frames to be sent on the control stream (#2754)

Kazuho Oku <> Tue, 11 June 2019 03:43 UTC

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From: Kazuho Oku <>
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Subject: Re: [quicwg/base-drafts] Lessen the divergence from the HTTP/2 prioritization scheme by requiring all PRIORITY frames to be sent on the control stream (#2754)
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> For example, it seems a defaulting request weight of 1 or 0 would be a more HTTP/2 like solution than adding a default placeholder? But possibly it doesn't matter that much?

I do not think it matters much.

And I think that servers might want to play some game here, for example giving higher default precedence to responses that carry CSS files until a PRIORITY frame is being received.

That said, I think I prefer the design principle to be "provide something that is guaranteed to be at worst as good as HTTP/2." Giving least precedence to requests for which the client-specified priority is yet to be known is a natural way to achieve that.

> Are there outstanding PRs for the rest of the migration back to more H2-like priorities?

Just filed #2781. I think that #2761 and #2781 are the remaining changes that we need to make, in order to allow browsers use the same prioritization scheme as the ones they've used in HTTP/2 (with the exception being that idle prioritized streams are replaced by placeholders).

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