From owner-freebsd-questions Thu Mar 6 10:57:57 2003 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 48A4037B401 for ; Thu, 6 Mar 2003 10:57:55 -0800 (PST) Received: from famine.e-raist.com (famine.e-raist.com [65.100.40.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6CEEC43FAF for ; Thu, 6 Mar 2003 10:57:54 -0800 (PST) (envelope-from aburke@nullplusone.com) Received: from thebe (evrtwa1-ar10-4-40-153-150.evrtwa1.dsl-verizon.net [4.40.153.150]) (authenticated bits=0) by famine.e-raist.com (8.12.2/8.12.2) with ESMTP id h26Ivmau082800; Thu, 6 Mar 2003 10:57:53 -0800 (PST) From: "Aaron Burke" To: "Jonas Fornander" , Subject: RE: Mirroring/load-balance two servers Date: Thu, 6 Mar 2003 10:57:42 -0800 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: <029001c2e3ac$6133f3f0$0800a8c0@master> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > Does anyone know if there is a "simple" way to mirror two servers > without spending $$$$$ on hardware? I'm NOT talking about mirroring the > OS and the files, I'm talking about sending http requests to a second > server if the first server is down/un-reachable. This is sometimes > referred to as load-balancing. > > The second server doesn't have to be updated in realtime, it just needs > to have a fairly current version of the data files of the main server. > So, for example if the main server goes off line for any reason, then > web pages would be served up from the second server instead. > > Can this be accomplished with DNS? To my knowlege, yes. Lets say you had a server called www. You would just give it two addresses in your domain configuration files. www IN CNAME 12.34.56.78 www IN CNAME 9.10.11.12 www IN CNAME 65.4.3.21 The DNS standard will give out a different address for every query. To get the address 12.34.56.78 twice, you would have to make 4 unique queries for the server records. One good example of this is to look at www.yahoo.com in nslookup. Default Server: localhost.jupiter.sol Address: 127.0.0.1 > www.yahoo.com Server: localhost.jupiter.sol Address: 127.0.0.1 Non-authoritative answer: Name: www.yahoo.akadns.net Addresses: 216.109.125.73, 216.109.125.70, 64.58.76.223, 216.109.125.72 216.109.125.67, 216.109.125.65, 216.109.125.66, 64.58.76.227, 64.58.76.228 216.109.125.71, 64.58.76.230, 216.109.125.69, 64.58.76.225 Aliases: www.yahoo.com > > Jonas Fornander - System Administrator > Netwood Communications, LLC - www.netwood.net > Find out why we're better - 310-442-1530 > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message