Re: [hybi] Last Call: <draft-ietf-hybi-thewebsocketprotocol-10.txt> (The WebSocket protocol) to Proposed Standard

Mark Andrews <marka@isc.org> Mon, 25 July 2011 03:00 UTC

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To: John Tamplin <jat@google.com>
From: Mark Andrews <marka@isc.org>
References: <CALiegf=pYzybvc7WB2QfPg6FKrhLxgzHuP-DpuuMfZYJV6Z7FQ@mail.gmail.com> <CAP992=FJymFPKcPVWrF-LkcEtNUz=Kt9L_ex+kLtjiGjL1T46w@mail.gmail.com> <4E28A51F.4020704@callenish.com> <CALiegf=4K2oWfmZjGMD7J_jyaDtS3i+Mu7R0Wh75Rr+MrQCjtw@mail.gmail.com> <20110722054345.GE18126@1wt.eu> <9031.1311500145.687172@puncture> <20110724105223.GL22405@1wt.eu> <CALiegfkTVg2=k4d8rxmpqXmaRUihRmhtgfF4QRUTAKic7gBk5w@mail.gmail.com> <20110724121147.GR22405@1wt.eu> <CALiegf=GDDKdXOXgz3oognh6=qRDKFUSrRfLOtOoUucAxr4p3w@mail.gmail.com> <20110724183343.GY22405@1wt.eu> <20110725004658.A3AE71221C03@drugs.dv.isc.org> <CABLsOLD-KM6DnR8HvfGH8N1M=1bZ4z8zus0YDczaXSfocBQ+Bw@mail.gmail.com>
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Date: Mon, 25 Jul 2011 12:59:14 +1000
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Cc: Server-Initiated HTTP <hybi@ietf.org>, IETF-Discussion <ietf@ietf.org>
Subject: Re: [hybi] Last Call: <draft-ietf-hybi-thewebsocketprotocol-10.txt> (The WebSocket protocol) to Proposed Standard
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In message <CABLsOLD-KM6DnR8HvfGH8N1M=1bZ4z8zus0YDczaXSfocBQ+Bw@mail.gmail.com>
, John Tamplin writes:
> 
> On Sun, Jul 24, 2011 at 8:46 PM, Mark Andrews <marka@isc.org> wrote:
> 
> > Adding a SRV lookup should add 0ms if it isn't there as you should be
> > making A, AAAA and SRV lookups in parallel.  Non-existance is as
> > cachable as existance is.
> 
> But you have to wait until the SRV returns even if the A/AAAA response comes
> back first, so there is a non-zero cost even with an optimal implementation.
> I am not arguing whether the cost is worth the benefits, only that there is
> a cost in any case.

In 99.9999% of cases the three answers will come in within 1ms of
each other and you may be waiting on the A or AAAA record.  It
really doesn't take any longer to answer a SRV query compared to a
A or AAAA query.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org