Elixir/Erlang and autoscaled EC2 servers - how to make them best buddies

Thu, 03 Mar 2016 02:22:00 +0000

At Find a Player, we’ve been trying to figure out how we want to cluster our Elixir servers - so that they can share state between each other - recently. Because we come from ruby (ie, not a high-availability background), when we want to discover other machines in a network we’d traditionally use something like Consul - of which I wrote a ruby library called Diplomat (which admittedly needs some love).

However, after chatting with Gordon Guthrie - a guy who’s been working with Erlang for over 13 years - over twitter, he told us to checkout :net_adm.world/0. Which does pretty much exactly what we want, straight out of the box.

Distributed Web Systems with Consul, Diplomat, Envoy and HAProxy

Thu, 24 Jul 2014 01:30:00 +0100

As part as my never-ending quest to improve how I build cool things, I’ve been working for some time on building out infrastructure to help automate and monitor how my apps and servers are doing. I’ve written about horizontal scaling before, but today I’d like to get into one specific facet of its implementation: automated network discovery, and how we use it at FarmGeek to build reliable applications.

The Problem

So lets say you have a few servers - a node balancer, two application servers and a database server, for example. Everything’s working fine until BAM, one of your application servers crashes. To make things worse, in this scenario for an unexplained reason nobody finds out about this. However your HAProxy checks work and so the node leaves the connection pool as expected.

Devops on John Hamelink

Elixir/Erlang and autoscaled EC2 servers - how to make them best buddies

Distributed Web Systems with Consul, Diplomat, Envoy and HAProxy

The Problem