When dealing with a high traffic web site it is often nice to implement some sort of caching mechanism or load balancer into your site architecture. Varnish cache is often a popular caching daemon used to serve cached web pages. Varnish in most cases also acts as a reverse proxy and detects values in the header of the request to delegate traffic in a specific way.
The Drupal CMS provides a robust set of tools for anyone looking to get a site up and running in a short amount of time. All you need to do is download Drupal, setup a theme on a hosting provider, and essentially you have a website up and running. Very easy, affordable, and simple, right? Often times something that is overlooked is how the “voodoo” or “black magic” makes that site work under the hood.