[AWS] How to detect an AWS server has been killed?

[David Marceau]

emartel@cic.teleco.ulpgc.es wrote:
> 
> Hello,
> 
>    I am writing my server with AWS.  This server (server 1) sends
> forms to the client browser. Apart from this server, I have
> other server (server 2) which can replace the server 1. When the
> server 1 is killed the message "netscape is
> unable to locate the server..." is shown on the client browser. How
> can the server 2 get this message before the client browser ?
> 
>   Is it possible a solution with the current  release of AWS?
> 
>                 Thanks,
> 
> -------------------------------------------
> Ernestina Martel Jordan
> Dpto. de Ingenieria Telematica
> Despacho 211. Pabellon C.
> Campus Universitario de Tafira, s/n
> 35017 Las Palmas de Gran Canaria. Spain
> Fax:+34 928 451243  Tfno.:+34 928 452876
> -------------------------------------------
> 
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Hi there,

The situation you are describing IMHO is a small part of what is called
the "failover" mechanism.
The problem itself you are describing IMHO does not reside in AWS code
or your code for that matter.

Check out this open-source which is exactly what you want to do:
http://www.vergenet.net/linux/fake/
Fake has been designed to switch in backup servers on a LAN. In
particular it has been designed to backup Mail, Web and Proxy
servers during periods of both unscheduled and scheduled down time. 
Fake allows you to take over the IP address of another machine in the
LAN by bringing up an additional interface and making use of
ARP spoofing. The additional interface can be either a physical
interface or an IP alias. 

It is part of a bigger open-source project which entails solving among
other things "failover" situations:
http://linux-ha.org/
You might want to use this also.

You might also want to look at the following "failover"/routers/switches
docs for more perspective:
http://205.150.126.238/ApplicationNotes/failover.pdf
http://nonstop.compaq.com/view.asp?IO=tcpippd
http://ps-ax.com/failoverd/failoverd-pod.html
http://oss.sgi.com/projects/failsafe/
http://www.europe.redhat.com/training/rhce/rh401_desc.php3
http://www.steeleye.com/products/linux/

I hope this helps.

Santé bonheur,
David Marceau