USETL

Abstract

Growing popularity of serverless functions is driving the need to optimize the execution platform to reduce resource usage and increase the number of functions that can be executed concurrently. This reduces the provider's costs and increases profit. While current serverless solutions use containers and/or virtual machines, we propose a unikernel based design called USETL which is specialized for serverless extract, transform, load (ETL) workloads. Our design is motivated by a number of key observations: serverless functions are stateless, ephemeral and event-driven. Further, each function's specific purpose is known at invocation time. Unikernels are a natural fit for execution contexts with these properties: they are minimal kernels packaged with a single application in a single address space, which makes them incredibly lightweight. Our design removes network and storage components entirely, replacing them with high level APIs tailored to the needs of serverless ETL functions. Virtualizing I/O at the runtime library interface reduces memory and CPU overheads, yielding higher consolidation density.