Google used to provide prebuild Android images of libWebRTC library, and in fact, it’s (still) the recomended way to use them on its own documentation. But starting on WebRTC M80 release (January 2020), they decided to deprecate the binary mobile libraries, and the reasons were that the builds were intended just only for development purposes, and users were already building it themselves with their own customizations, or using third party libraries that embedded them (where have been left developers that just want to build a WebRTC enabled mobile app?), and they just only provided another build in August 2020 (1.0.32006) to fill some important security holes, in case someone (everybody?) was still using the binary mobile libraries.

When working on npm projects with multiple subprojects as dependencies, there’s a problem when you need to do frequent updates. Ideally, that dependencies should have their own tests and versioning, but that’s not always possible (for example, private packages) and sometimes we would need to publish multiple development versions while trying to debug some obscure issues. This is tedious and nasty, so that’s why so much people like monorepos.

Jest is one of the most populars testing frameworks for Javascript and Node.js. Originally developed by Facebook, it’s a one-stop-shop with testing, assertions, code coverage… but this implies some critics, like requiring more than 50mb of dependencies. Also, somewhat recently was shown to be maintained mostly by a single person, being that the reason why updates and maintenance was so much slow, so they decided to transfer it to OpenJS foundation. Also there has been several long standing critics about not providing a pure environment, or the fact that Jest parses the code, leading to some complexities when needing to configure transpilation. That has lead to several people looking for alternatives, and having now a built-in test runner in Node.js, I decided to see myself how to migrate to it.

When installing Mafalda packets, a problem I’ve suffered several times are install times, specially since I’m using git dependencies. I tried to reduce times by publishing some of the most common packages to npm, so removing need to install and compile development dependencies like Typescript, but still install times were huge for no reason, so I needed some way to measure the install time of each one of the dependencies. This lead out options like UNIX time command or tools like slow-deps, so just by change, I found on StackOverflow a reference to gnomon.

I’m advocate of automatization, and that includes not only CI/CD pipelines, but also I wanted to do it for documentation publishing. Mafalda is split in a lot of packages (currently more than 30!), so I wanted to have a single place where to publish the documentation of all of them. Github Pages allows to host a website for your organization or username by free (this blog and personal site already makes use of it), and it can also host automatically a website for each repository as sub-paths of your username/organization main website. Problem is, that it only works for open source repositories or for paid plans, and most of the Mafalda SFU repositories are private ones. So since the Mafalda SFU project website is already hosted on Github Pages as a public repository, I decided to store and serve from it all the other repositories documentation as well… doing it in an automated way :-)

Although Mafalda SFU is mainly focused on vertical scaling of Mediasoup and the WebRTC stack, the main problem I’ve found companies are facing is about how to easily implement Medisoup horizontal scaling. I’ve been working on a solution for this problem for a while on, and since Mafalda is build on top of Mediasoup, it’s also needed to help it to provide transparent vertical and horizontal scaling, so let’s see how it works.

When aproaching the horizontal scaling of WebRTC servers, we have two main aproachs: decentralized P2P, and using a central server. Each one has its own drawbacks and advantages, and I had difficulties to identify what aproach was the best, since I usually have a personal preference for pure P2P architectures, but they are not the most simple nor always the more efficient ones. So when deciding how to aproach Mafalda horizontal scaling, I needed to consider the pros and cons of each use case I would need, and here we have my conclusions.

Mafalda SFU is a massively vertical and horizontal scalable SFU built on top of Mediasoup. This allow to have (theorically) unlimited sized WebRTC-based video room calls.