Website failover

[Pete Tenereillo]

Actually, since the stated requirements are "web" and " the same request
goes automatically to server B", even a low TTL with a manual failover will
not do. After the switchover, some huge % of users are almost certain to be
stuck on the dead server for 1/2 hour or more (check out
http://www.tenereillo.com/GSLBPageOfShame.htm and other docs on that site
for details about why).

If the servers A and B are co-located, and you absolutely need server B to
get traffic only if A is failed (true active/standby), a local server load
balancer (LSLB) is the answer. Cisco/F5/Nortel/etc. sell those. If you need
a cost effective one, check out loadbalancer.org. If you don't need true
active/standby, just return both A records and let A and B share the load.


----- Original Message ----- 
From: "Richard Peiper" <rpeiper at waca.com>
To: "John" <john.vanLit at ratio-it.nl>; <comp-protocols-dns-bind at isc.org>
Sent: Tuesday, July 20, 2004 11:26 AM
Subject: RE: Website failover


>
> You don't do that with DNS, you need a loadbalancer of some
> kind... Or you can set the TTL very low and change it by hand when they
> go down (which I would not recommend)
>
> Richard
>
>
> -----Original Message-----
> From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org] On
> Behalf Of John
> Sent: Tuesday, July 20, 2004 7:16 AM
> To: comp-protocols-dns-bind at isc.org
> Subject: Website failover
>
> all,
>
> I have two web servers server A and server B. both servers host the
> same web application. Server B is the slave server off server A. both
> servers are located on different places. How can I configure DNS so
> that a www request always goes to the primary server A but when server
> A is offline the same request goes automatically to server B?
>
> Regards,
>
> John van Lit
>
>
>