Round robin DNS is a technique in which load balancing is performed by a DNS server instead of a strictly dedicated machine. A DNS record has more than one value IP address.
When a request is made to the DNS server which serves this record, the answer it gives alternates for each request. For instance, if you had a three webserver that you wished to distribute requests between, you could setup your DNS zone as follows:
# vi /var/named/domain.com.db
Append/modfiy www entry:
www IN A 1.2.3.4
IN A 2.3.4.5 IN A 3.4.5.6
IN A 4.5.6.7 # /etc/init.d/named restart
When a query is made to the DNS server it will first give the IP of 1.2.3.4 for the www host. The next time a request is made for the IP of www, it will serve 2.3.4.5 and so on.
But in this case , if the website is an interactive one ( login ) then there should be again synchronisations b/w the 3 websites too right ? How will you achienve that ? Simply scp ?