A networked computer system provides a way to quickly switch to a backup
data center when a primary data center fails. Each data center includes a
redirect table that specifies a geographical area corresponding to each
user. The redirect table is replicated on one or more data centers so
that each data center has the same information. When a data center fails,
the redirect table in one of the non-failed data centers is updated to
specify a new data center for each client that used the failed data
center as its primary data center. A network dispatcher recognizes that
the failed data center is unavailable, and routes a request to the backup
data center. Network routing logic then issues a redirection command that
causes all subsequent requests from that client to be redirected directly
to the backup data center.