Electric Imp Moves to Erlang Programming Language

Originally posted, 16 June 2014, to the Electric Imp blog. Preserved here.

At the heart of the Electric Imp platform is our cloud connectivity service which provides the secure connection between every imp out in the wild and their corresponding agents. From there, imps can interact with the world - smartphone apps, web services, databases and so on.

This critical piece of infrastructure deals with connection security, ensuring every imp has the latest code to run, and that the connection load is distributed evenly across our server farms. Until now, this service has been implemented in node.js, a high performance javascript based platform, but today we’re announcing that this piece is moving to Erlang.

What is Erlang? It’s a programming language designed from the ground up to build massively scalable systems with high availability, and is extensively used in telecoms, banking and e-commerce applications. Just as those markets are very demanding of their platforms, so are we.

Erlang is the right foundation for our platform because we get a system that enables us to focus on adding features, while the language, libraries and runtime take care of scalability, distribution and fault tolerance. Improved scalability means that we can smoothly handle the increasing number of devices connected to the Electric Imp platform. Distribution and fault tolerance mean that if something does go wrong you should not notice.

We’re particularly excited that Erlang supports zero-downtime upgrades. We are still experimenting with this feature in depth, but it does mean - for most things - that in the future we’ll no longer need maintenance windows. We’ll be able to release new features and fixes with no disruption to the service we offer.

Where Are We Now

We’ve been running the Erlang connectivity service on our staging environment for the last couple of months, and beta testers have been using an Erlang production server for the past few weeks. We plan to start moving developer imps to the Erlang servers this week, and if all goes smoothly the production servers will switch to Erlang over the next month or so.

Generally, the move should be completely transparent to both developers and end users, and we have not made any changes to the server components that host your agents and handle your HTTP requests. If any issues do arise that we have not anticipated during our extensive internal testing, we will be investigating and addressing each one as they emerge.

What’s Next?

The Internet of Things promises to change the way we connect and interact with devices and each other in a profound ways. The transition to Erlang is just one of the many ways Electric Imp will deliver on that promise and continue to offer the most advanced, scalable and innovative connectivity platform possible.

– Roger Lipscombe, Backend Developer

Looking in the Wayback Machine, I see that we migrated the other core cloud component – the agent server – to Erlang about a year later, in June 2015.

It’s mentioned in passing in a blog post about hitting 5 billion messages between devices and agents per month. This is a noteworthy milestone, but adds nothing to this blog, so I haven’t taken a copy.