what is load balancing ? How www.yahoo.com uses it for their web servers?

Answer 1

Hi,

Load balancing is a technique for transfer incoming query's to others simultaneously running web server. For that Yahoo & google both using squid proxy for load balancing.

In yahoo, all yahoo user account is stored in SAN (storage area network) a centralized server. Whenever any Internet user make query for yahoo web server, query is goes to first list of squid proxy. For that they setup more than 10 squid proxy server for load balancing. every squid proxy server getting account info from SAN and process the query. If one squid server is handel his full capacity and he receive new query then he transfer this query to other squid server for processing.

All this is setup in unix base OS like Linux, HP UX, IBM AIX.

The same is in google also.

Good luck!!!!

Answer 2

Load balancing can be very complex, involving hundreds of clustered proxy servers.

Basically there is 1 PC(web server) that you connect to when you go to yahoo.com. The IP address it advertises to is is a Virtual address. The server has a bunch of other servers behind it that we cant see and it knows all of thier Ip addresses. So you you are on the yahoo home page and click the mail button, the web server redirects you to the mail server.

Proxies are a mess! To speed up content many companies use proxy servers to cache data. This speed up the whole net. Need any more info or detail just email me...