Serpens: A High Performance FaaS Platform for Network Functions

Abstract

More and more enterprises deploy applications on Function-as-a-Service (FaaS) platforms to improve resource efficiency and save monetary costs. Network Functions (NFs) suffer from staggered peaks of traffic patterns and could benefit from fine-grained resource multiplexing in FaaS platform. However, naively exploring existing FaaS platforms to support NFs can introduce significant performance overheads in three aspects, including slow instance startup, remote state access for NFs, and costly packet delivery between NFs. To address these problems, we propose <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> , a high performance FaaS platform for NFs. First, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> proposes a reusable NF runtime design to slash instance startup overhead. Second, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> designs a novel state management mechanism to support local state access. Third, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> introduces an advanced service chaining approach to avoid extra packet delivery. Besides, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> designs an NF scaling mechanism to minimize performance fluctuation. We have implemented a prototype of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> and conducted comprehensive experiments. Compared with the NFs and Service Function Chains (SFCs) that run on existing FaaS platforms, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>${\sf Serpens}$</tex-math></inline-formula> can improve the throughput by more than 10× and reduce the latency by more than 90%.