KubeCon + CloudNativeCon Europe 2023

This talk will describe GreenCourier in detail, present experimental results, and motivate the development of other carbon-aware solutions in the cloud ecosystem. GreenCourier targets a new cloud computing paradigm called Serverless Computing aka Function-as-a-Service, in which users are only responsible for writing small pieces of code called functions while all infrastructure management is handled by the cloud service provider. To reduce carbon emissions on function invocations, GreenCourier incorporates an intelligent scheduling policy for Kubernetes that schedules serverless functions across geographically interconnected Kubernetes clusters depending on their carbon-efficiency. To this end, GreenCourier implements a scheduling plugin for Kubernetes based on the Scheduler API that obtains periodic information from the carbon-aware sdk to determine the carbon-efficiency of a geographical region. As the FaaS platform, GreenCourier utilizes the serving component of Knative. On function invocation, GreenCourier listens for the creation of Knative objects and automatically schedules them on the most carbon-efficient region. For seamlessly establishing geographically distributed Kubernetes multi-cluster topologies, GreenCourier utilizes Liqo based on the Virtual Kubelet.