The first server being very busy will give slow responses and low performance. This approach can be implemented through software or hardware techniques. Many types of server level applications can be written to accomplish session aware routing through software. One of them is described here. A Web farm consists of two or more servers that host and serves a common logical-DNS host name.
Load balancing is done in a DNS round-robin fashion.
As long as all hyperlinks reference relative URLs, the browser will assume the URL is on the same host, and will submit the request to that host for processing. This technique requires a site to use only relative-URL hyperlinks within its documents. The IP address of the virtual server is registered with the DNS server, while the IP addresses of the servers themselves remain undisclosed. When this virtual server receives requests, the router distributes the requests to one of them. The entire group of servers thus appears to the user as a single server.