WebAssembly as an Enabler for Next Generation Serverless Computing

Abstract

WebAssembly is a new binary instruction format and runtime environment capable of executing both client side and server side workloads. With its numerous advantages, including drastically reduced cold start times, efficiency, easy portability, and compatibility with the most popular programming languages today, it has the potential to revolutionize serverless computing. We evaluate the impact of WebAssembly in terms of serverless computing, building on top of existing research related to WebAssembmly in cloud and edge environments. To this end, we introduce a novel benchmarking suite comprised of 13 different functions, compatible with WebAssembly, and focusing on both microbenchmarking and real-world workloads. We also discuss possibilities of integrating WebAssembly runtimes with the application programming interfaces and command line interfaces of popular container runtimes, representing an initial step towards potential reuse of existing orchestration engines in the future, thus solving the open issue of WebAssembly workload scheduling. We evaluate the performance of such an integration by comparing the cold start delays and total execution times of three WebAssembly runtimes: WasmEdge, Wasmer, and Wasmtime to the performance of the containerd container runtime, using distroless and distro-oriented container images. Results show that WebAssembly runtimes show better results in 10 out of 13 tests, with Wasmtime being the fastest WebAssembly runtime among those evaluated. Container runtimes still offer better compute performance for complex workloads requiring larger execution times, in cases where cold start times are negligible compared to the total execution time.