Lightweight vs. Traditional Orchestration: A Performance Study of WebAssembly and Containers
WebAssembly (Wasm) is often presented as a lightweight alternative to containers, especially for serverless edge deployments. In practice, orchestration overhead can dominate startup and runtime efficiency on resource-constrained nodes. We evaluate this overhead on a two-node Raspberry Pi 4 cluster across three lightweight Kubernetes distributions (K3s, K0s, KubeEdge), two Wasm orchestration frameworks (SpinKube, wasmCloud), Knative, and native Kubernetes containers. The evaluation combines end-to-end startup measurements with CPU and memory telemetry in two scenarios: deployment and loaddriven scaling. Across the tested configurations and workloads, native container orchestration provides the lowest overall overhead and the shortest startup times for complete applications. Empirical results demonstrate that binary compilation times for AI-based Wasm components reach up to 18 seconds on edge devices. This effectively neutralizes the technology's theoretical cold-start advantage and causes traditional containers to consistently outperform Wasm in end-to-end startup latency. The results also show that orchestration behavior is strongly affected by autoscaling support, runtime integration choices, and platform-specific constraints.