So getting through a from scratch Kubernetes build was fun and deeply interesting. And on top of that I’ve started finding all sorts of great hybrid cloud technologies that would have been great to have on so many projects I worked on in the past (these projects all suffered big cloud myopia unfortunately). One of these that is really interesting and worth noting is the OpenFaaS project, think of it as AWS Lambdas or Azure Functions but running locally or in a Kubernetes cluster.

It’s really a great project for many reasons, one of the top of which is the function limits are orders of magnitude larger than most major serverless function providers (12TB memory limit, 96 CPU cores, 290 year execution limit). Everyone working in AWS is aware of the strict limits their Lambda’s impose on the workloads, these can be design crippling, forcing teams to re-work how they orchestrate the logical components of their applications to accommodate alternatives. Where as OpenFaaS only seems to have limits inherent to the programming language and frameworks, so it’s suitable for a vastly wider set of discrete processing tasks. I’ve been on several projects in the past where the AWS Lambda timeout limit suddenly killed forward progress. And the amount of re-work required to the data or the logic/compute easily eclipsed standing up an OpenFaaS cluster. To the point where it seems almost criminal not to run an OpenFaaS cluster for at least long running occasional discrete functions.

And to be clear, OpenFaaS is not the same as AWS Lambda. It’s not running something like Firecracker underneath necessarily. There isn’t a sophisticated over provisioning scheme in place. But it does make clever use of docker pause to provide resource conservation so you can load a lot of functions on an OpenFaaS cluster. And you don’t even need a full Kubernetes cluster to take advantage of it, the basic Daemon is called faasd, which can run independently of K8s on a VM or say a RasberryPi.

OpenFaaS is event driven, and provides it’s own REST API to support flexible invocation. There are built in monitoring and control mechanisms to round out the project. So in many ways OpenFaaS can supplement or maybe even replace your serverless function sub systems. At the very least I feel this project is something you should keep in your back pocket for when the limits of big cloud serverless functions suddenly prove to be roadblocks for your projects.