Subject: Re: Load Balancing with Anycast
To: None <tech-net@NetBSD.org>
From: Tillman Hodgson <firstname.lastname@example.org>
Date: 01/26/2005 09:13:59
On Wed, Jan 26, 2005 at 03:54:42PM +0100, Zafer Aydogan wrote:
> Hello Mailing List,
> Just an Idea.
> I thought about using anycast (zebra/quagga) for determinig the closest
> netbsd www server worldwide, where all servers have the same ip adress
> (multiple with same ip) and routing is done to the closest one.
> Maybe in the Future, when the demand is huge :)
My understanding of anycast, from testing it on a "metanetwork" composed
of tunnels between private networks and running a mixture of Quagga and
Zebra for routing, is that it's only good for stateless protocols.
Basically, anything that uses TCP (like HTTP traffic) generally won't be
a good candidate for anycast because there is no guarantee that packets
belong to the connection will all arrive at the same server.
Anycast *is* great for handing UDP-based services like DNS and Kerberos.
In many ways it's a more robust way to handling slave KDCs -- less
client-side configuration (assuming that kadmin to a particular master
KDC isn't an issue in your environment).
"The state has no business in the bedrooms of the nation."
-- Pierre Elliott Trudeau