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Re: HTTP/2 Priorities Proposal

From: Jeff Pinner <jpinner@twitter.com>
Date: Tue, 15 Apr 2014 09:56:08 -0700
Message-ID: <CA+pLO_i65_wYCPgJuMx9=RmDqTHPBD5yd6_WzcY6F0AexEZP+g@mail.gmail.com>
To: Mark Nottingham <mnot@mnot.net>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
A question was raised on the pull request of whether or not we should allow
exclusive root dependencies, i.e. whether or not to allow inserting a
stream between the connection and all of its children.

Client authors, do you thing this is an important use case to support with
no additional frame overhead?

(I will note that this can still be achieved with a non-exclusive
dependency followed by re-prioritizing all children onto the new stream.)


On Mon, Apr 14, 2014 at 3:47 PM, Mark Nottingham <mnot@mnot.net> wrote:

> For those who haven't seen it:
>   https://github.com/http2/http2-spec/pull/453
>
> Cheers,
>
>
> On 10 Apr 2014, at 3:46 am, Jeff Pinner <jpinner@twitter.com> wrote:
>
> > Are there any objections to me opening a pull requests with these
> changes as a more concrete proposal?
> >
> >
> > On Wed, Apr 9, 2014 at 8:05 AM, Jeff Pinner <jpinner@twitter.com> wrote:
> > To change all weights, we have to issue PRIORITY frames for each root.
> >
> >
> > Yes, changing the weight of a stream would require issuing a PRIORITY
> frame for each stream. With this proposal you cannot do it by changing the
> weight of the group.
> >
> > I believe that this is an acceptable tradeoff.
> >
> > Let me give a similar example where we reached the same conclusion:
> >
> > At one point we considered whether or not RST_STREAM should have an
> ASSOCIATED flag. The argument was that the server could send PUSH_PROMISE
> frames for some stream that the client did not want to receive pushes for.
> With the flag, the client could reset all of those streams with a single
> frame. We decided it was perfectly acceptable to send one frame for each
> stream and dropped the flag.
> >
> > With this change, to change the weight of multiple streams, you must
> issue one frame per stream, but IMHO this is worth it given the reduced
> complexity of the change, and more importantly, the ability that this
> change introduces of being able to completely proxy the priority
> information.
> >
> >
> >
>
> --
> Mark Nottingham   http://www.mnot.net/
>
>
>
>
>
Received on Tuesday, 15 April 2014 16:56:36 UTC

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