Re: HTTP router point-of-view concerns

James M Snell <jasnell@gmail.com> Thu, 11 July 2013 20:04 UTC

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From: James M Snell <jasnell@gmail.com>
Date: Thu, 11 Jul 2013 13:02:30 -0700
Message-ID: <CABP7RbfGYsryOsEWW+UWJ+fdVejiRQSHH0DF_Kw4Pf=EJQX+rw@mail.gmail.com>
To: Roberto Peon <grmocg@gmail.com>
Cc: Martin Thomson <martin.thomson@gmail.com>, Amos Jeffries <squid3@treenet.co.nz>, HTTP Working Group <ietf-http-wg@w3.org>
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Subject: Re: HTTP router point-of-view concerns
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On Thu, Jul 11, 2013 at 12:35 PM, Roberto Peon <grmocg@gmail.com> wrote:
>[snip]
>
> The DoS vector you're talking about is not a DoS vector if the intermediary
> resets all streams before the change-of-state-size comes into effect.
> When the state size is 0, one should be able to use some kinds of 'indexed'
> representations, so long as those representations refer only to items in the
> static tables. Why do you believe that this would use more or less CPU? (It
> should use less CPU and less memory...)
> [snip]

Well, as far as I can tell, according to the current header
compression draft, there is no "static table". The header table is
pre-populated, yes, but those items would fall out of the header table
via eviction as the table fills. There is nothing in the current
header compression draft that says those items are permanent.... Given
that, and given that we've already established that reducing the
header table size forces eviction, setting the size to zero would
cause all of the pre-populated items to be evicted.

- James