$\mathsf{Aurora}$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 $\mathsf{Aurora}$Aurora, with the following properties: •

Leaderless: it does not require a leader, hence completely get rid of the fail-over protocol.

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Scalable: it can scale up to $11$11 replicas.

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Robust: it behaves well even under a poor network connection.

We provide a full-fledged implementation of $\mathsf{Aurora}$Aurora and systematically evaluate its performance. Our benchmark results show that $\mathsf{Aurora}$Aurora achieves a throughput of around two million Transactions Per Second (TPS), up to 8.7$\boldsymbol{\times}$× higher than the state-of-the-art leaderless SMR.