CETUS: Towards Proportional Capacity Provisioning and Cost-Effectiveness in Frontend Servers

Hyper-scale data centers emerged in the last decade largely adopt a multi-tiered architecture with the frontend clusters dedicated to serve high-demand user facing web traffic. In order to mitigate the overhead caused by Transport Layer Security (TLS) that protects the communications between users and the data center, the frontend clusters usually apply hardware TLS acceleration. In this paper, we analyze the inefficiencies that lie in today's frontend clusters, and propose CETUS, an improved data center frontend system architecture. CETUS improves the cost effectiveness of frontend clusters through cluster consolidation that fully offloads the TLS and network stack to a CETUS SoC; it enables proportional capacity provisioning through pooling of resources and dynamic division of frontend tasks with a flow diverter. Compared to existing frontend clusters that are equipped with commercial TLS acceleration solutions, CETUS balances out the frontend resource utilization, and provides up to 86.2% in cost reduction while maintaining at the same level of throughput and latency of the frontend.