From owner-freebsd-questions@FreeBSD.ORG Wed Mar 29 16:27:56 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C662916A400 for ; Wed, 29 Mar 2006 16:27:56 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id C495443D77 for ; Wed, 29 Mar 2006 16:27:47 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 0C2AE5D34; Wed, 29 Mar 2006 11:27:47 -0500 (EST) Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 55154-07; Wed, 29 Mar 2006 11:27:44 -0500 (EST) Received: from [192.168.1.3] (pool-68-160-194-11.ny325.east.verizon.net [68.160.194.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 083BD5C53; Wed, 29 Mar 2006 11:27:44 -0500 (EST) Message-ID: <442AB583.7090700@mac.com> Date: Wed, 29 Mar 2006 11:27:47 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: scuba@centroin.com.br References: <20060329125019.V4053@trex.centroin.com.br> In-Reply-To: <20060329125019.V4053@trex.centroin.com.br> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at codefab.com Cc: freebsd-questions@freebsd.org Subject: Re: Network tunning X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Mar 2006 16:27:56 -0000 scuba@centroin.com.br wrote: > I need some help to fine tune a mail server. > The machine is running (Fbsd 5.4) for a long time, but I'm seeing > too many connections droped in sendmail log, and some users complains > about timeout connecting to smtp port. > > From the handbook I increased the kern.ipc.somaxconn to 1024 as > sugested. Using "ps axH" shows about 350 processes. > > With "netstat -s -p tcp" worrys me the value of "listen queue > overflows", is it normal? No, it implies that the system couldn't process the incoming connections rapidly enough to drain the queue of requests, which is why your users are seeing timeouts. Basicly, your mail server has a certain maximum throughput before it bottlenecks and extra sendmail processes get stuck because they can't get enough resources, and the thing falls over. Running out of RAM and starting to swap would be a sure sign of this happening, check your vmstat output... What kind of mail volume are we talking about here? You should be able to do on the order of 1-10 messages a second on reasonable hardware (aka ~1 million/day). There's a book called "Sendmail Performance Tuning", hmm, by Nick Chistianson or something like that, which you should try to get ahold of. You could start by limiting the maximum number of child processes that sendmail will spawn to a more reasonable number which will fit into the available RAM and leave room for any other anti-spam or virus-scanning things, too. -- -Chuck