Nano-consensus: Ultra-fast, Quorum-less Coordination on the Wire

Consensus, widely regarded as the most fundamental primitive in distributed systems, lies at the core of countless services that require coordination among remote processes. Datacenter services typically achieve consensus through long-established, quorum-based algorithms such as Paxos and Raft, including recent re-adaptations for kernel bypass datapaths (e.g. smartNIC/RDMA-based consensus). While these optimizations can reduce latency to the μs-scale, they remain constrained by inherent message complexity, namely the need for acknowledgments from majority quorums to tolerate faults and arbitrary message delays. Our approach takes a step further from bare acceleration of classical primitives, focusing instead on leveraging FPGA-smartNIC and priority-queue reservation to achieve synchronous remote interactions in practice. We use synchrony to devise a novel, efficient quorum-less consensus protocol which we use to build Nano-consensus: a novel hardware consensus engine. Nano-consensus operates at network line rate and can reach consensus in 1.03μs for single-packet instances, delivering 3.82× latency and 4.8× improvements over the state of the art. We demonstrate how Nano-consensus can be integrated into distributed applications to boost both performance and consistency.