Priority-aware Inter-Server Receive Side Scaling

Abstract

Next-generation automotive networks will be characterized by a high number of interconnected sensors, actuators and applications on electronic control units communicating with each other over a high-speed Ethernet backbone network. As these applications have various criticalities, high volumes of fluctuating traffic with different priorities will have to be processed in a reliable and efficient manner. To cope with these challenges, we present Priority-aware Inter-Server Receive Side Scaling (prioRSS), a new SmartNIC-based hardware accelerator designed for automotive compute nodes. prioRSS builds upon Receive Side Scaling and introduces priority-awareness into an intra- and inter-node load balancer. It uses a priority-partitioned indirection table within which flows of the same priority are bundled. Low-latency reconfigurations issued by a Network Health Monitoring software allow for adapting the table content to changing network conditions. Simulative evaluations and comparisons to a priority-unaware version of our design show that prioRSS enables per-priority resource assignments without degrading end-to-end packet latencies while using the same table memory space. Paired with a priority-aware scheduler, end-to-end latencies of high priority flows can be notably reduced compared to average packet latencies, at the expense of lowest priority traffic. The best results are acquired when partitioning the table proportionally to the associated traffic share.