Speaker Deck

PyConZA 2012: "Fractal Architectures" by Laurens Van Houtven

by Pycon ZA

Published October 5, 2012 in Programming

An alternative take on the traditional layered service architecture.

Traditional service architecture wisdom generally tells us to build services like this:

Load balancer in front
Web servers, preferably stateless
Database (with a caching layer)
That works great for a wide variety of use cases. The point of this talk isn't to deprecate that design, but to discuss a radically different one.

The design I will present in this talk is one consisting of recurring, identical components. It localizes state to individual application servers and persists it to durable stores later. It aims to be easier to scale horizontally: that is, enabling you to increase throughput by simply adding more machines to the homogenous cluster.

I will talk about its benefits, such as performance and how it fits in well with many cloud providers' services, but also its downsides, such as the inherent complexities of distributed systems. I analyze these qualities to come to a conclusion about which kinds of project this design is suitable or not suitable for.

In this talk I will discuss both the abstract concepts and the practical implementation that I have built using Twisted and Axiom (a simple object database on top of SQLite 3), which is currently running in production. Although I will touch on the practical implementation, the talk should still be useful for anyone wanting to implement a similar idea using different tools.