From owner-freebsd-arch@FreeBSD.ORG Thu Sep 8 15:31:43 2005 Return-Path: X-Original-To: arch@FreeBSD.org Delivered-To: freebsd-arch@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 792D916A41F; Thu, 8 Sep 2005 15:31:43 +0000 (GMT) (envelope-from ume@mahoroba.org) Received: from ameno.mahoroba.org (gw4.mahoroba.org [218.45.22.175]) by mx1.FreeBSD.org (Postfix) with ESMTP id AE6D743D45; Thu, 8 Sep 2005 15:31:41 +0000 (GMT) (envelope-from ume@mahoroba.org) Received: from kasuga.mahoroba.org (IDENT:eGwum2CXhJznky8MKtoYSQLVEKs+s0GdhIEtlmJ6y9ascSvl6ejEi2buhtJF8a2U@kasuga.mahoroba.org [IPv6:3ffe:501:185b:8010:20b:97ff:fe2e:b521]) (user=ume mech=CRAM-MD5 bits=0) by ameno.mahoroba.org (8.13.4/8.13.4) with ESMTP/inet6 id j88FVUjA008147 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 9 Sep 2005 00:31:34 +0900 (JST) (envelope-from ume@mahoroba.org) Date: Fri, 09 Sep 2005 00:31:30 +0900 Message-ID: From: Hajimu UMEMOTO To: Doug Barton In-Reply-To: <430FCAF5.90701@FreeBSD.org> References: <430FCAF5.90701@FreeBSD.org> User-Agent: xcite1.38> Wanderlust/2.14.0 (Africa) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 Emacs/22.0.50 (i386-unknown-freebsd6.0) MULE/5.0 (SAKAKI) X-Operating-System: FreeBSD 6.0-BETA4 X-PGP-Key: http://www.imasy.or.jp/~ume/publickey.asc X-PGP-Fingerprint: 1F00 0B9E 2164 70FC 6DC5 BF5F 04E9 F086 BF90 71FE Organization: Internet Mutual Aid Society, YOKOHAMA MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0 (ameno.mahoroba.org [IPv6:3ffe:501:185b:8010::1]); Fri, 09 Sep 2005 00:31:35 +0900 (JST) X-Virus-Scanned: by amavisd-new X-Virus-Status: Clean X-Spam-Status: No, score=-5.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.0.4 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on ameno.mahoroba.org Cc: arch@FreeBSD.org Subject: Re: [CFR] reflect resolv.conf update to running application X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Sep 2005 15:31:43 -0000 Hi, >>>>> On Fri, 26 Aug 2005 19:07:49 -0700 >>>>> Doug Barton said: dougb> I've been following this thread with interest, and while I applaud the dougb> effort that's gone into this I'm not sure it has a very high cost/benefit dougb> ratio for the majority of FreeBSD systems. This would potentially be useful dougb> for mobile systems that will often be moved into different networks, but dougb> frankly I don't see a benefit for the vast majority of systems that will dougb> have the same resolv.conf file for weeks, months, or years. I'm also dougb> thinking of various types of high performance systems that actually do dougb> thousands of DNS queries a minute. While a stat() call in the resolver path dougb> for every query might not be noticeable on a "typical" system, they would dougb> add up on systems that are already being stressed. Yup, there might be no benefit for non-mobile users. However, I believe it is still useful for mobile users. So, I changed to look a kernel environment variable. If resolver_reread_conf is set, the feature will be activated. You can find my new patches from: http://www.imasy.or.jp/~ume/FreeBSD/resolver-check-resolv.conf-20050908.diff http://www.imasy.or.jp/~ume/FreeBSD/dhclient-script-renew-20050908.diff dougb> Personally, I would much rather we add some method of "HUPing" the resolver dougb> to re-read resolv.conf. That way we could add that command to dougb> dhclient-script and send it whenever the resolv.conf file is actually dougb> changed. This could also be used by sysadmins for typically "static" systems dougb> instead of having to restart services on those systems. Since a resolver is in each applications, I think it is hard to send a HUP signal to resolvers without having a daemon which does DNS query. Sincerely, -- Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan ume@mahoroba.org ume@{,jp.}FreeBSD.org http://www.imasy.org/~ume/