[erlang-questions] Fault-Tolerant TCP/IP Servers

[Richard Kelsall]

David Mercer wrote:
> Say I have a TCP/IP server (e.g., a web server, FTP server, etc.) 
> written in Erlang, and I want it to work through hardware failures; I 
> need at least two of them.  The problem is, clients are connecting to 
> the primary’s IP address, so when it fails, client connections are 
> refused instead of being rerouted to the secondary.  What is the Erlang 
> approach to solving this?
> 
> My thought is that you have the secondary detect the failure and send 
> the appropriate commands to the network to redirect traffic for the 
> primary server’s IP address to the secondary.  That’s my idea, but I 
> don’t really know if this is the appropriate solution, nor how to 
> implement something like this in Erlang.

Just to add that you can also play games at the DNS level to send web
requests to different IP addresses. These sorts of things :

http://www.tylek.org/?p=23
http://www.akadia.com/services/dns_round_robin.html

Others will have much better knowledge than me though.


Richard.