Akka.NET Request for Contributors: Akka.Cluster

Akka.NET - Distributed Actor Model for .NET

The next major milestone for Akka.NET is Akka.NET v1.1, the primary focus of which is a stable, production-ready release of the Akka.Cluster module.

We’ve made some solid progress towards that goal in some of our maintenance releases, but I came to the realization over the past couple of months that the way we’ve been working with our contributors isn’t the most effective way for the project to achieve these milestones.

In this post I’m going to invite you, a .NET developer who’s interested in distributed computing, to work with me directly on the guts of Akka.Cluster and take on a project that’s bigger than you or me. And it’ll be awesome - you’ll learn a lot and make a real difference.

But in meantime, let’s get some background for context.

What does Akka.Cluster do and why is it important?

Akka.Cluster is the foundation of Akka.NET’s high-availability toolchain; it’s what allows you to build elastic, distributed, fault-tolerant peer-to-peer networks of Akka.NET applications that don’t have any single point of failure or bottleneck.

My Petabridge co-founder Andrew explained it well in Akka.NET: Introduction to Clustered Applications w/ Akka.Cluster (21:32), embedded below:

TL;DR; Akka.Cluster is what makes it feasible for .NET developers to build applications that are capable of being highly available and stateful in a way that’s largely unheard of in the .NET ecosystem. It’s capable of truly amazing stuff - just try out the WebCrawler Akka.Cluster demo we wrote and watch what happens when you spin up multiple Crawler nodes in the middle of a job.

All of the cool stuff depends on Akka.Cluster

Akka.Cluster is pretty cool in and of itself, but all of the really exciting modules all depend on it. For example:

Want those cool toys? Then let’s ship Akka.Cluster first.

The current state of Akka.Cluster

Akka.Cluster has existed in some form since September, 2014 - so it’s been around for about a year and users are running it under serious production workloads. The library has been mostly code complete for a while.

However, there’s one major problem with Akka.Cluster: me. I’ve been the bottleneck on Akka.Cluster for most of its lifespan.

Historically I’ve created the impression that I have it all under control with Akka.Cluster, but the truth is that it’s a project that’s bigger than any one person. Today, if I have to take time away from Akka.Cluster to work on projects for Petabridge, speak at conferences, or whatever, then all progress on Akka.Cluster comes to a halt. That sucks and it’s my fault.

So let’s create a possibility where lots of people understand how the guts of Akka.Cluster work and are motivated to improve upon it and share the knowledge of how it works with others. That’s what this is really all about.

I need your help

I have to come clean here - I’ve been reluctant to really ask for help on Akka.Cluster for a long time, because:

I don’t believe either of those anymore. First and foremost, Akka.Cluster is a module that’s too important to be the responsibility of just one contributor. If something happened to me then someone else would have to step up the take over that part of the project. Rather than have it come to that, I would rather coach some capable developers beginning this week on how that system works so others can always contribute and lead there.

Redundancy is just as important for people as it is for servers. Plus: I’m not perfect. I fuck stuff up all the time. And that’s ok!

As for the second point: Akka.Cluster is not hard, it’s just different - based on distributed programming concepts that are unfamiliar to most developers, but totally transformational once understood.

So here it is: if you’re interested in distributed systems, .NET, and open source then I would like you to become a contributor with me on Akka.Cluster. I’m still going to be focusing most of my contributions in that area, and I’d like to do it alongside a team of contributors.

What needs to be done

The burden of this module is its high quality assurance requirements. Writing multi-node specs; ensuring that the MultiNode TestKit’s behavior is correct; beating racy and inconsistent behavior out of the system; and thoroughly documenting the expected behavior of a cluster under lots of different scenarios.

Here’s what needs to be done to complete our work on Akka.NET v1.1:

How to get involved

The first thing to do if you want to get involved is to fill out this interest form below!

We’re asking people to fill this out so I can do the following to help you help us:

I’m committed to doing that for you - and, frankly, pretty excited about it. I think this will be something huge.

Once you’ve filled this out, check out the outstanding issues for Akka.NET v1.1 on our waffle (in the “For Next Release” tab) and hop into the Akka.NET Gitter chat and introduce yourself if you haven’t already! Looking forward to working with you!

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I'm the CTO and co-founder of Petabridge, where I'm making distributed programming for .NET developers easy by working on Akka.NET and Helios.

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