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Re: Call for Consensus: Remove "reference set" from HPACK (to address #552)

From: Greg Wilkins <gregw@intalio.com>
Date: Wed, 16 Jul 2014 12:13:48 +1000
Message-ID: <CAH_y2NFna2Gh9=su5q7PsmcR+n_XizTXY-aVt4CmsHdr5u5uVQ@mail.gmail.com>
To: HTTP Working Group <ietf-http-wg@w3.org>
I ran the hpack test data through the various options being discussed for
several different header table sizes:

HPACK/HEADER TABLE01024409616384h2-1264.22%47.06%42.18%41.82%h2-12-noRefSet
64.22%47.39%42.57%42.44%h2-12-noRefSet-noCopy64.22%47.16%42.50%42.67%
h2-12-noRefSet-noCopy-static164.22%47.18%42.36%40.97%

There is actually very little variation in results +/- 1% which is likely
to be below the variation due to different data sets.       So on that
basis we should go for the simplest mechanism, which is either
h2-12-noRefSet-noCopy  or h2-12-noRefSet-noCopy-static1

But if we trust that data set, then the best compression was achieved with
h2-12-noRefSet-noCopy-static1 and a large header table.    Also
h2-12-noRefSet-noCopy-static1 was better than h2-12-noRefSet-noCopy for all
but the 1024 table size.

So on this data we should go with h2-12-noRefSet-noCopy-static1

h2-12 == the HPACK used by draft 12 of HTTP
noRefSet == no Reference Set
noCopy == Do not copy static fields to the header table
static1 == Static indexes are 1-61, dynamic are 62-...


cheers








On 16 July 2014 11:01, James M Snell <jasnell@gmail.com> wrote:

> On Tue, Jul 15, 2014 at 1:21 PM, Martin Thomson
> <martin.thomson@gmail.com> wrote:
> > On 15 July 2014 12:14, Jason Greene <jason.greene@redhat.com> wrote:
> >> Whatever happened with this idea? Searching my archives I couldn’t find
> it getting rejected. I also don’t see an issue filed for it.
> >
> > Search for "typed codecs" and variations on the same.
> >
> > Also: http://tools.ietf.org/html/draft-snell-httpbis-bohe-13  (note
> > the version number)
> >
>
> Note also that the version number is reflective only of my own
> editing/publishing style and not of any particular amount of
> consideration from the WG
>
> - James
>



-- 
Greg Wilkins <gregw@intalio.com>
http://eclipse.org/jetty HTTP, SPDY, Websocket server and client that scales
http://www.webtide.com  advice and support for jetty and cometd.
Received on Wednesday, 16 July 2014 02:14:17 UTC

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