If you have large amount of traffic, you may want to consider Load Balancing.
Load balancing is the act of distributing the load of a single web site or other
service onto multiple physical servers. A load-balanced server set provides redundancy
and practically infinite scalability. Load balancing is especially important for
networks where it's difficult to predict the number of requests that will be issued
to a server. Busy Web sites typically employ two or more Web servers in a load
balancing scheme. If one server starts to get swamped, requests are forwarded
to another server with more capacity. If one server goes down, there is no noticeable
effect on end users and no downtime. The term load balancing refers to front-end
(i.e. incoming traffic) distribution only; load balancing does not include back-end
functionality such as data replication or mirroring; that further service is known
as clustering.