Pi Cluster

August 8 2017

I have an impulse buying problem. Or rather I have a prolonged short term attention span problem. Hell, I might just be lazy. In any event, occasionally I’ll come across something that piques my interest on the internet and conclude that I must replicate it to a degree. While I’d like to say that the parts I purchase for various projects always get used for their intended purpose, all too often they end up in a box on a shelf somewhere to be rediscovered another day. But not this time!

Pi clusters were all the rage two years ago. Like any fad, I had to get in on it a couple years after the fact. After buying several Pi 3s, various cords, an ethernet switch, and a power supply I realized that my original plan of building a hadoop cluster was, well, dumb. While I love map reduce and use it near daily at work, I couldn’t actually think of a practical use for it in any of my current endeavors. So like any good web developer I changed my scope and decided to scale this site instead.

This site now runs on a combination of five Pis. Two of the Pis act as a static server for images and css/javascript files. Another two run a truncated version of this site. They act as self healing template engines really. The fifth Pi sits in front of the servers and acts as a reverse proxy to load balance incoming requests and also abstract SSL logic. This configuration is also advantageous as I can easily remove Pis when I see fit to use them in other projects. In regards to networking I’m still bottlenecked by 10 Mb/s upload speed of typical internet packages and the onboard 10/100 LAN of the Pis but at least this site can handle some moderate traffic now without imploding. I’m sure this site’s four readers will greatly appreciate these upgrades…

I used this design to print the rack. It’s only about ten bucks for a rack online but I wanted an excuse to use the 3D printers at work!