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Date: Fri, 12 Sep 1997 08:05:35 -0700
From: Don Wilde <don@PartsNow.com>
Reply-To: don@PartsNow.com
Organization: Soligen, Incorporated
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To: Doug White <dwhite@resnet.uoregon.edu>
CC: Robert Strickler <RStrickler@hq.koch.com>,
        "'freebsd-questions@freebsd.org'" <freebsd-questions@FreeBSD.ORG>
Subject: Re: Clustering/fail-over capability?
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It would seem that there's several simpler ways to do this, if there
isn't a lot of database update going on on the server, and you don't
need instantaneous response.

First is the simplest: have the standby machine ping'ing the first
through a dedicated ethernet channel or SIO, and have it shut down the
primary via a HARDWIRE switch... pull the plug, restart the inetd, and
go.

Second is to use a gateway-configured machine as an intelligent switch.
You can change routing tables on the fly, and kill/restart the router in
milliseconds. There is no reason why you can't also have a dedicated
(unroutable) connection between the two for data updates.

You could also build a little microcontroller-based 10Base-T switch that
would switch the cable connection almost instantly. This way, all you'd
have to do is to sense activity on the net and switch the wires with
CMOS switches, no software changes necessary.

Now, as to how to do this on an enterprise-wide basis, if that is what
you are asking, I haven't a clue. :)
-- 
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 V_=_=_DW ===--- Don Wilde [don@PartsNow.com] [http://www.PartsNow.com ]
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