Feather: Lightweight Container Alternatives for Deploying Workloads in the Edge

Recent years have seen the adoption of workload orchestration into the network edge. Cloud orchestrators such as Kubernetes have been extended to edge computing, providing the virtual infrastructure to efficiently manage containerized workloads across the edge-cloud continuum. However, cloud-based orchestrators are resource intensive, sometimes occupying the bulk of resources of an edge device even when idle. While various Kubernetes-based solutions, such as K3s and KubeEdge, have been developed with a specific focus on edge computing, they remain limited to container runtimes. This paper proposes a Kubernetes-compatible solution for edge workload packaging, distribution, and execution, named Feather, which extends edge workloads beyond containers. Feather is based on Virtual Kubelets, superseding previous work from FLEDGE. It is capable of operating in existing Kubernetes clusters, with minimal, optional additions to the Kubernetes PodSpec to enable multi-runtime images and execution. Both Containerd and OSv unikernel backends are implemented, and evaluations show that unikernel workloads can be executed highly efficiently, with a memory reduction of up to 20% for Java applications at the cost of up to 25% CPU power. Evaluations also show that Feather itself is suitable for most modern edge devices, with the x86 version only requiring 58-62 MiB of memory for the agent itself.