HTTP: The Definitive Guide

Why Redirect?

Redirection is a fact of life in the modern Web because HTTP applications always want to do three things:

• Perform HTTP transactions reliably

• Minimize delay

• Conserve network bandwidth

For these reasons, web content often is distributed in multiple locations. This is done for reliability, so that if one location fails, another is available; it is done to lower response times, because if clients can access a nearer resource, they receive their requested content faster; and it’s done to lower network congestion, by spreading out target servers. You can think of redirection as a set of techniques that help to find the “best” distributed content.

The subject of load balancing is included because redirection and load balancing coexist. Most redirection deployments include some form of load balancing; that is, they are capable of spreading incoming message load among a set of servers. Conversely, any form of load balancing involves redirection, because incoming messages must somehow be distributed amongst the servers sharing the load.