How Dns Provide Load distribution to identical server?

Answer 1

The most common method is called "round robin", where the DNS server has 2 or more A records. For instance, if you have 3 servers, with IP addresses 10.1.1.2, 10.2.1.2, and 10.3.1.2, the first query would be given 10.1.1.2, the second would get 10.2.1.2, the third 10.3.1.2, the fourth would get 10.1.1.2 again, and so on.

If that doesn't quite cut it, it's possible to get DNS servers that will bias the results based on system load - so for instance if you have 3 servers, and one is a bit idle, it may return that server 40% of the time and the other two 30% each, rather than 33% each.

And if that doesn't suffice, you can contact the guys at Akamai or Foundry regarding their "global scale" balancers, that play lots of network tricks to figure out where you are and direct your query to the closest server.

Answer 2

It will provide load distribution because if one server is busy with DNS or anything else for that matter, the backup server will take on the responsibility of resolving the particular address.