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Re: [hybi] Background info: Properties of sendfile()

Willy Tarreau <w@1wt.eu> Fri, 06 August 2010 06:29 UTC

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Date: Fri, 06 Aug 2010 08:29:28 +0200
From: Willy Tarreau <w@1wt.eu>
To: Roberto Peon <fenix@google.com>
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References: <4C5B1695.6070704@gmx.de> <F8E2F702-9F74-4316-B3B2-D5A731409ABF@apple.com> <4C5B2029.90403@gmx.de> <AANLkTim1WeCRfcPxXUNQcVhb4+t_TtDQDv2bXaxOQ=bk@mail.gmail.com> <01098AD0-FBF4-4A61-B565-947C95722BAA@apple.com> <AANLkTi=qQSND5BvUP5+P=wJ7E8SG6NncGZH8U8+VYwZ0@mail.gmail.com> <20100806004907.GF27827@shareable.org> <C0FC87B7-C51C-4B36-BC16-DBDB0B00A20F@gbiv.com> <20100806012845.GI27827@shareable.org> <AANLkTimuvuj87qwQi_1Gjg47-gGrCsDCQ5TDd5zvOw1N@mail.gmail.com>
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Cc: "Roy T. Fielding" <fielding@gbiv.com>, "hybi@ietf.org" <hybi@ietf.org>
Subject: Re: [hybi] Background info: Properties of sendfile()
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On Thu, Aug 05, 2010 at 06:47:48PM -0700, Roberto Peon wrote:
> Thus my statement of "theoretical" benefits.
> I've not seen the benefits of either splice or sendfile yet.

At least I've seen it. Haproxy happily forwards traffic at 10 Gbps
with only 25% of one CPU core on a 2.66 GHz Core2Duo using splice().
And some file sharing sites make a big use of it ! Without splice,
it hardly achieves 10 Gbps at 100% CPU.

Anyway, it's unclear to me why we would need to send large amounts
of data over WebSockets. File serving could well be performed by
the web server itself.

Regards,
Willy

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