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From: Rashid Karimov <rashid@rk.ios.com>
Message-Id: <199511141907.OAA02701@rk.ios.com>
Subject: Re: Multiple http servers - howto ?
To: terry@lambert.org (Terry Lambert)
Date: Tue, 14 Nov 1995 14:07:10 -0500 (EST)
Cc: luigi@labinfo.iet.unipi.it, hackers@FreeBSD.org
In-Reply-To: <199511141527.IAA19839@phaeton.artisoft.com> from "Terry Lambert" at Nov 14, 95 08:27:58 am
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		Hi there folx,

> 
> > I have read that some http servers (probably some machines at NCSA)
> > are actually a cluster of servers attached to the same ethernet. Client
> > transparently contact one of the servers. I would like to know how this
> > is achieved, e.g.
> > 
> >   i) by supplying different IP translations for the same name;
> >  ii) by a clever use of ARP
> > iii) by some other technique which I do not know
> 
> #1.  Via DNS.  The requesting hosts are rotored through a list of the
> addresses.
> 
> It isn't a very good scheme, mostly because caching exists.

	It is importante that you provide 0 expiration times
	for the corresponding A records - so that (at least RFC compliant)
	DNS servers will not cache the record ....

	There are a few pitfalls in http ... namely lack of support
	for multiple WWW domains on the same computer(the URL gets
	stripped, so the server never sees the domain name in URL)
	and the mechanism for authentic redirection to the mirror Web site -
	in case when the first server is overloaded or/and is under maintenance.

	Would be great if this issues could be addressed in future 
	implementation of the hhtp proto... will take some time tho
	to upgrade all the servers and browsers


	Rashid