Using DNS for low cost Failover


Posted by Lawrence Sinclair on 16 Apr 2010 at 16:31

It could make exceptional sense to make use of yourdns host for load balancing and failure toleranceby usinground robin and DNS Failover. This could save the substantial expense of dedicated load balancing hardware or machines to run load balancing software or scripts. And of course, the load balancer itself is an extra point of failure that could be avoided by having this logic handled by your DNS provider.
For one domain, just list a set of IP addresses in the DNS records, each for different redundant machines. Traffic is spread across this list of servers using a round robin approach. Combine this with DNS Failover which checks to see if the machines at each IP are working and redirects if necessary. Essentially, if a machine goes down, it can just get dropped from the round...