QFaaS: Accelerating and Securing Serverless Cloud Networks with QUIC

Serverless computing has greatly simplified cloud programming. It liberates cloud tenants from various system administration and resource management tasks, such as configuration and provisioning. Under this new cloud computing paradigm, a single monolithic application is divided into separate stateless functions, i.e., function-as-a-service (FaaS), which are then orchestrated together to support complex business logic. But there is a fundamental cost associated with this enhanced flexibility. Internal network connections between functions are now initiated frequently, to support serverless features such as agile autoscaling and function chains, raising communication latency. To alleviate this cost, current serverless providers sacrifice security for performance, keeping internal function communications unencrypted. We believe that the emerging QUIC protocol, which has secured and accelerated HTTP communications in the wide area, could proffer a solution to this challenge. We design a QUIC-based FaaS framework, called QFaaS, and implement it on the OpenFaaS platform. Our design explicitly ensures that existing serverless applications can directly benefit from QFaaS without any application code modification. Experiments on synthetic functions and real-world applications demonstrate that QFaaS can reduce communication latency for single functions and function chains by 28% and 40%, respectively, and save up to 50 ms in end-user response time.