Drupal tuning

Anyone who runs a site/server for very long will likely find out about the gruesome underbelly of the online work - spammers. They come in many shapes and sizes (most are bots), and with different purposes each, but they each have this in common - they hurt your site/server and it's available resources.

Below are some things to look out for and some methods to take care of one particular type of spam, referrer spam, which can cripple a site/server in no time. With enough referrer spam you'll have what amounts to a denial of service attack (e.g., so many junk requests that the server can't even tend to the real ones).

Example of how serious this can be
Recently one of the sites we host had a big traffic day thanks to being front paged at Fark.com and Foobies.com. 18,000+ unique visitors in 18 hours. Suffice it to say that put quite a load on the shared environment they were hosted in. Well, guess what - the (unrelated) spam attack the site received a few days later actually created more than twice the load on the server that the huge amounts of legitmate traffic did!

Slashdotted, Dugg, Farked. These are all terms that site operators, bloggers, and web developers are very familiar with. They imply having a site 'front paged' at a website that drives a LOT of traffic to your own site.

Over the past week one of the sites we host, ended up on the front page of Fark.com and Foobies.com at the same exact time. It added up to some very busy days for a site which is hosted in a shared environment (meaning that it has to share resources of a server with other sites) as well as some useful knowledge concerning:

• what kind of load a Drupal powered site can handle when in a shared enviroment
• how to optimize Drupal's capability to handle a large number of visitors

To begin, it need to be understood that overall optimization for site traffic is going to depend on a gazillion different factors. If you don't have a reliable server stack which is already optimimized this article will only do you so much good. Apache, MySQL, and PHP need to be running reliably, and well tuned.