We present FunLess, a Function-as-a-Service (FaaS) platform tailored for the private edge cloud system. FunLess responds to recent trends that advocate for extending the coverage of serverless computing to private edge cloud systems and enhancing latency, security, and privacy while improving resource usage. Unlike existing solutions that rely on containers for function invocation, FunLess leverages WebAssembly (Wasm) as its runtime environment. Wasm's lightweight, sandboxed runtime is crucial to have functions run on constrained devices at the edge. Moreover, the advantages of using Wasm in FunLess include a consistent development and deployment environment for users and function portability (write once, run everywhere) We validate FunLess under different deployment scenarios, characterised by the presence/absence of constrained-resource devices (Raspberry Pi 3B+) and the (in)accessibility of container orchestration technologies - Kubernetes. We compare FunLess with three production-ready, widely adopted open-source FaaS platforms - OpenFaaS, Fission, and Knative. Our benchmarks confirm that FunLess is a proper solution for FaaS private edge cloud systems since it achieves performance comparable to the considered FaaS alternatives while it is the only fully-deployable alternative on constrained-resource devices, thanks to its small memory footprint.

翻译：本文介绍FunLess，一个专为私有边缘云系统设计的函数即服务平台。FunLess响应了近期将无服务器计算覆盖范围扩展至私有边缘云系统、在提升资源利用率的同时增强延迟、安全性和隐私性的趋势。与现有依赖容器进行函数调用的解决方案不同，FunLess采用WebAssembly作为其运行时环境。Wasm轻量级的沙箱运行时对于在资源受限的边缘设备上运行函数至关重要。此外，FunLess使用Wasm的优势包括为用户提供一致的开发部署环境以及函数可移植性。我们在不同部署场景下验证FunLess，场景特征包括是否包含资源受限设备以及容器编排技术Kubernetes的可用性。我们将FunLess与三个生产就绪且广泛采用的开源FaaS平台——OpenFaaS、Fission和Knative进行对比。基准测试证实，FunLess是实现FaaS私有边缘云系统的合适解决方案，因其在实现与对比平台相当性能的同时，凭借其较小的内存占用，成为唯一能在资源受限设备上完全部署的替代方案。