Date: Wed, 23 Apr 2008 16:19:29 +0200 From: Clement Laforet <sheepkiller@cultdeadsheep.org> To: Ivan Voras <ivoras@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: Http Accept filters (accf_http) Message-ID: <20080423141929.GA61109@goofy.cultdeadsheep.org> In-Reply-To: <fuli49$pa3$1@ger.gmane.org> References: <8481.1208889581@critter.freebsd.dk> <480E3E66.3000303@samsco.org> <fuli49$pa3$1@ger.gmane.org>
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[-- Attachment #1 --] On Tue, Apr 22, 2008 at 10:34:14PM +0200, Ivan Voras wrote: > Scott Long wrote: > >Poul-Henning Kamp wrote: > >>In message <480E307B.901@quis.cx>, Jille writes: > >>>Hello, > >>> > >>>I've read about accf_http(9) some time ago, and I was wondering about > >>>it's performance. > >>>Does it increase performance on all workloads ? > >>>(I'm intrested in the improvements for a PHP-apache-webserver with > >>>about 50 request/second average.) > >> > >>I doubt you will see measurable performance difference from using > >>request filters at such low traffic. > >> > > > >The accept filters do reduce service latency and probably have a small > >benefit in CPU utilization. 50 requests/sec is probably enough to see > >a benefit for something like PHP or PERL. It definitely won't hurt, and > >even if there's no measurable benefit now, it'll help prepare you for > >scaling in the future. > > Does anyone know why accf_accept is disabled by default in the ports' > stock Apache 2.2 (it's disabled in the default config files)? I thought > it was because it was dangerous or flawed for some reason, though (at > least for light loads comparable to those of OP) it seems to work fine. There's not technical reason actually. It's an "opt-in" feature ;-) In the early 2.2.x times, httpd used to print a warning when accf_http is disabled. It was, of course, just a matter of loglevel. apache ran perfectly fine, but a warning got printed. Some users started complaining about how my port was broken, sometimes in very rude manner. So I decided to explicilty disable AcceptFilter unless apache22_http_accept_enable is set to "YES" in /etc/rc.conf. clem [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFID0VwsRhfjwcjuh0RAhV6AKC0OdQMC+8MyYDIvNwcnJErQUPkfgCeL3u2 qoeEXJAGT67Pipq9Jsg/vPU= =VUZr -----END PGP SIGNATURE-----
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