ExoPlane: An Operating System for On-Rack Switch Resource Augmentation

The promise of in-network computing continues to be unrealized in realistic deployments (e.g., clouds and ISPs) as serving concurrent stateful applications on a programmable switch is challenging today due to limited switch's on-chip resources. In this paper, we argue that an on-rack switch resource augmentation architecture that augments a programmable switch with other programmable network hardware, such as smart NICs, on the same rack can be a pragmatic and incrementally scalable solution. To realize this vision, we design and implement ExoPlane, an operating system for on-rack switch resource augmentation to support multiple concurrent applications. In designing ExoPlane, we propose a practical runtime operating model and state abstraction to address challenges in managing application states correctly across multiple devices with minimal performance and resource overheads. Our evaluation with various P4 applications shows that ExoPlane can provide applications with low latency, scalable throughput, and fast failover while achieving these with small resource overheads and no or little modifications on applications.