Paper 2023/1463 Original: eprint.iacr.org/2023/1463 ↗

Aurora: Leaderless State-Machine Replication with High Throughput

Abstract

State-machine replication (SMR) allows a {deterministic} state machine to be replicated across a set of replicas and handle clients' requests as a single machine. Most existing SMR protocols are leader-based requiring a leader to order requests and coordinate the protocol. This design places a disproportionately high load on the leader, inevitably impairing the scalability. If the leader fails, a complex and bug-prone fail-over protocol is needed to switch to a new leader. An adversary can also exploit the fail-over protocol to slow down the protocol. In this paper, we propose a crash-fault tolerant SMR named Aurora, with the following properties: • Leaderless: it does not require a leader, hence completely get rid of the fail-over protocol. • Scalable: it can scale up to 11 replicas. • Robust: it behaves well even under a poor network connection. We provide a full-fledged implementation of Aurora and systematically evaluate its performance. Our benchmark results show that Aurora achieves a throughput of around two million Transactions Per Second (TPS), up to 8.7X higher than the state-of-the-art leaderless SMR.