From owner-freebsd-questions Sat Oct 12 23:02:01 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id XAA10220 for questions-outgoing; Sat, 12 Oct 1996 23:02:01 -0700 (PDT) Received: from synwork.com (root@synwork.com [199.3.234.4]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id XAA10201 for ; Sat, 12 Oct 1996 23:01:55 -0700 (PDT) Received: from localhost (flaq@localhost) by synwork.com (8.7.5/8.6.12) with SMTP id BAA00933; Sun, 13 Oct 1996 01:00:52 -0500 (CDT) Date: Sun, 13 Oct 1996 01:00:51 -0500 (CDT) From: SysAdmin To: Wes Peters cc: James FitzGibbon , questions@FreeBSD.ORG Subject: Re: Redundancy in FBSD web server In-Reply-To: <199610130437.WAA01056@obie.softweyr.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Sat, 12 Oct 1996, Wes Peters wrote: -->James FitzGibbon writes: --> > I need to set up a web server that (in my client's humble words) "CANNOT --> > EVER BE DOWN". They've got the budget, so I recommended two servers that --> > can serve domains concurrently. --> > --> > I'd be interested in hearing how people have/would implement this. My --> > thoughts so far would be to: --> > --> > a) Use a powerful box as the main server, with a backup box mirroring --> > sites and ready to take over should the main one go down. --> > --> > -or- --> > --> > b) Use machines of equal power, using a DNS entry with multiple A records --> > to shuffle requests back and forth. --> > --> > Opinions appreciated, including ways of detecting a downed host and taking --> > over (ifconfig aliasing) IPs of a machine that has crashed. --> -->I've just finished (5 minutes ago, literally) a project of this sort -->at my "day" job: a redundant, 24x7 television broadcast automation -->system. Our system, a large audio/video switch, uses a control -->processor based on an M68000. In order to acheive reliable backup, we -->put two of them in the system, and have them monitor each others -->state. This is a really simplistic system, but it works fairly well.* --> -->What I'd suggest you do is to have two machines connected to your -->router. Each has a network interface, neither interface is the -->www.whatever address. When the "primary" machine boots, it adds the -->address of www.whatever as an alias for its network interface; the -->standby begins pinging (or attempting http connections to) the -->www.whatever address. If the standby machine detects the primary has -->gone down, by not answering the pings, it adds www.whatever as an -->alias for *its* network and takes over. I don't know if this is a possibility or not, but wouldn't you be able to have 2 machines, each with a network interface and multi-home the domain? One server could be the primary (IP #1) and the other could be secondary (IP #2) and mirror the primary at regular intervals. Mike ~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~ Syn-Work Media, Inc. | WWW Development & Hosting | Life Safety http://www.synwork.com | Systems Integration | CCTV mike@synwork.com | Voice/Data/Fiber | Access Control Flaq on IRC | Dukane Distributor | BICSI/RCDD :|:|:|: Powered By FreeBSD :|:|:|: Turning PC's Into Workstations ~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~