From owner-freebsd-stable@FreeBSD.ORG Mon Apr 5 20:43:05 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1A0381065672 for ; Mon, 5 Apr 2010 20:43:05 +0000 (UTC) (envelope-from jfarmer@goldsword.com) Received: from gateway16.websitewelcome.com (gateway16.websitewelcome.com [70.85.130.5]) by mx1.freebsd.org (Postfix) with SMTP id CF19E8FC14 for ; Mon, 5 Apr 2010 20:43:04 +0000 (UTC) Received: (qmail 17591 invoked from network); 5 Apr 2010 20:44:41 -0000 Received: from audi.websitewelcome.com (67.19.210.130) by gateway16.websitewelcome.com with SMTP; 5 Apr 2010 20:44:41 -0000 Received: from localhost ([127.0.0.1]:44322) by audi.websitewelcome.com with esmtpa (Exim 4.69) (envelope-from ) id 1Nyt8V-0007uB-00 for freebsd-stable@freebsd.org; Mon, 05 Apr 2010 15:43:06 -0500 Received: from 74.171.98.142 ([74.171.98.142]) by www.goldsword.com (Horde MIME library) with HTTP; Mon, 05 Apr 2010 16:43:06 -0400 Message-ID: <20100405164306.hmy4n8pvs4goc8ks@www.goldsword.com> Date: Mon, 05 Apr 2010 16:43:06 -0400 From: jfarmer@goldsword.com To: freebsd-stable@freebsd.org References: <1209800810.33861270466947931.JavaMail.root@dagobah.intersec.pl> <4BBA05A2.40706@intertainservices.com> <4BBA1823.1090305@gausus.net> <4BBA4334.1020506@interazioni.it> <4BBA4478.7030302@gausus.net> In-Reply-To: <4BBA4478.7030302@gausus.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable User-Agent: Internet Messaging Program (IMP) H3 (4.1.6) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - audi.websitewelcome.com X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - goldsword.com Subject: Re: fault tolerant web servers on freebsd X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Apr 2010 20:43:05 -0000 Quoting Maciej Jan Broniarz : > W dniu 10-04-05 22:08, Tonix (Antonio Nati) pisze: >> Maciej Jan Broniarz ha scritto: >>> W dniu 10-04-05 17:45, Mike Jakubik pisze: >> >> Just to use exact words, fault toulerancy is not possible with any >> FreeBSD/Linux O.S. >> F.T. means outage can occur in every moment, but all current operation >> will be always completed by other equipments; so there will not be >> interrupted/lost operations. > > Hmm. Thanks for the tip. Which *NIX os can be used to build an FT > solution then? Solaris? AIX? HP-UX? You're asking a question that has not easy or compete answer. Fault =20 tolerant at what level? Do you want to guarantee that _every_ DB =20 operation competes? What about random file reads or writes? Do you =20 want to guarantee that two identical operations with the same data =20 will produce the same result? (That's _not_ the same as the previous =20 questions...) So first you have to define your workload, then define what errors you =20 must avoid or allow, and then define how to deal with failures, =20 errors, etc. Then you can start talking about High Availability vs. level of Fault =20 tolerance, vs. .... John ----------------------------------------------------------------- J. T. Farmer GoldSword Systems, Knoxville TN Coach & Instructor Consulting, Knoxville Academy of the Blade Software Development, Maryville Fencing Club Project Management