network topology & sever capacity

I know google has over 10,000 servers running in massive clusters so yahoo is probably close to the same. distributed environment, once capacity nears add a few more to the cluster and so on.

Application providers like Yahoo have multiple servers, they have multi-tier applications, load balancing, redundancy, etc. For example, if you just do name search for "www.google.com", it will give you multiple IP addresses. And even that addresses will not be direct IP addresses of a web servers - it will be load balance appliences, i.e. F5, Cisco, etc. Each appliance may distribute requests, for example, to fifty servers. And each server may be a cluster of computers. Plus, when you do request, the request will be fullfilled by the application servers, which will do database request to separate database servers, and so on. Plus, each server could be connected to shared storage. So, it could be thousands and thousands servers involved in "Yahoo" business.

Good luck,

Mike
www.ciscoheadsetadapter.com