GoldFish: Serverless Actors with Short-Term Memory State for the Edge-Cloud Continuum

Abstract: Serverless Computing is a computing paradigm that provides efficient infrastructure management and elastic scalability. Serverless functions scale up or down based on demand, which means that functions are not directly addressable and rely on platform-managed invocation. Serverless stateless nature requires functions to leverage external services, such as object storage and KVS, to exchange data. Serverless actors have emerged as a solution to these issues. However, the state-of-the-art serverless lifecycle and event-trigger invocation force actors to leverage remote services to manage their state and exchange data, which impacts the performance and incurs additional costs and dependency on third-party services. To address these issues, in this paper, we introduce a novel serverless lifecycle model that allows short-term stateful actors, enabling actors to maintain their state between executions. Additionally, we propose a novel serverless Invocation Model that enables serverless actors to influence the processing of future messages. We present GoldFish, a lightweight WebAssembly short-term stateful serverless actor platform that provides a novel serverless actor lifecycle and invocation model. GoldFish leverages WebAssembly to provide the actors with lightweight sandbox isolation, making them suitable for the Edge-Cloud Continuum, where computational resources are limited. Experimental results show that GoldFish optimizes the data exchange latency by up to 92% and increases the throughput by up to 10x compared to OpenFaaS and Spin.