Moving Past Docker for Serverless: WebAssembly for Kubernetes Clusters at the Edge

Edge computing has become a critical part of IoT networks as demand for real-time data processing skyrockets. Serverless computing allows developers to write stateless and ephemeral functions while abstracting away infrastructure and scaling woes. However, when trying to deploy conventional serverless functions on resource-constrained edge devices, challenges exist such as high cold start times, high resource usage at idle, and architecture-specific deployments, among others. An emerging alternative to traditional solutions has been WebAssembly, abbreviated Wasm, which is characterized by its fast execution, compatibility with the most popular programming languages, and lightweight, portable binaries. We evaluate WebAssembly as an alternative to Docker containers by comparing execution times, memory footprint and container sizes. Our results show that Wasm configurations run 31.4 % faster on average, consume 59.5 % less memory, and produce images that are 86.5 % smaller, highlighting their efficacy in resource-scarce environments. These benefits come bundled with reduced idle resource usage, additional security sandboxing, and architecture-agnostic deployment.