RE: Can one mirror a web server ?

Well, if the servers are all on the same network, why not create a =
Virtual IP and bind DNS together for all those IPs that host the copy of =
the website and configure all the webservers in apache to use the local =
IP address?

Then point DNS for the website to the Virtual IP address? Can't that be =
done?



Warron French
Sr. Network Engineer
Xtria, LLC
8045 Leesburg Pike #400
Vienna, VA 22182
Desk: 703-821-6110
Main: 703-821-6000
Fax: 703-827-0374


-----Original Message-----
From: bind-users-bounce@isc.org [mailto:bind-users-bounce@isc.org]On
Behalf Of Jim Popovitch
Sent: Wednesday, February 02, 2005 4:17 PM
To: barrett bonden
Cc: comp-protocols-dns-bind@isc.org
Subject: Re: Can one mirror a web server ?


On Wed, 2005-02-02 at 15:53 -0500, barrett bonden wrote:
> Can one mirror a web server ?
>=20
> The idea is to make a failsafe and transparent dual computer system =
at two
> sites.
>=20
> This would involve (can it be done ?) one dns setting point to two ip
> addresses ?

Yes/No.

Yes: It can be done such that www.yourdomain.com resolves to multiple IP
addresses. Do a `host www.google.com` for an example.

No: What you will get with multiple A records is... well... multiple A
records. One user will get the first, the next visitor will get the
second, the third visitor will get the third. This achieves
load-distribution, but not failover. In the event that one IP goes
dead, that A record will still be distributed and the "lucky" visitor
will get a page timeout.

Question for Bind developers: Wny couldn't a feature (defaulted to off)
be added that allows for a simple ICMP test before a request is
returned. Yes it would slow things down, but it could allow for
rudimentary failover. Just a thought.

-Jim P.