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. One example of this might be to route all traffic to slave servers, or to route all traffic to a failover server in a case of an emergency.
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. One of those “voodoo” items in particular that I see overlooked often is how Apache, .htaccess, and Drupal all work together in keeping a custom site configuration in-sync.