Achieving low-latency consensus in geographically distributed systems remains a key challenge for blockchain and distributed database applications. To this end, there has been significant recent interest in State-Machine-Replication (SMR) protocols that achieve 2-round finality under the assumption that $5f+1\leq n$, where $n$ is the number of processors and $f$ bounds the number of processors that may exhibit Byzantine faults. In these protocols, instructions are organised into views, each led by a different designated leader, and 2-round finality means that a leader's proposal can be finalised after just a single round of voting, meaning two rounds overall (one round for the proposal and one for voting). We introduce Minimmit, a Byzantine-fault-tolerant SMR protocol with lower latency than previous 2-round finality approaches. Our key insight is that view progression and transaction finality can operate on different quorum thresholds without compromising safety or liveness. Experiments simulating a globally distributed network of 50 processors, uniformly assigned across ten virtual regions, show that the approach leads to a 23.1% reduction in view latency and a 10.7% reduction in transaction latency compared to the state-of-the-art.

翻译：在地理分布系统中实现低延迟共识，仍然是区块链和分布式数据库应用面临的关键挑战。为此，近期对状态机复制协议产生了浓厚兴趣，这类协议在假设 $5f+1\\leq n$（其中 $n$ 为处理器数量，$f$ 为可能发生拜占庭故障的处理器数量上限）的条件下，可实现两轮最终性。在这些协议中，指令被组织成视图，每个视图由不同的指定领导者主导，两轮最终性意味着领导者的提案仅需一轮投票即可最终确定，即总共两轮（一轮用于提案，一轮用于投票）。本文提出 Minimmit，一种拜占庭容错的状态机复制协议，其延迟低于以往的两轮最终性方案。我们的核心洞见是：视图推进与交易最终性可在不同的法定阈值下运行，而不会影响安全性或活性。在模拟由 50 个处理器组成的全球分布式网络（均匀分配于十个虚拟区域）的实验中，该方法相比现有最优方案，视图延迟降低了 23.1%，交易延迟降低了 10.7%。