This paper introduces Nemo-Nemo, a practical crash-fault tolerant (CFT) consensus protocol designed to outperform existing protocols in wide-area networks by bridging design principles from the CFT and Byzantine-fault tolerant (BFT) worlds. By structuring command propagation through a causally ordered DAG, Nemo-Nemo allows all consensus replicas to propose commands with a naturally self-regulating communication regime. By exploiting multi-leader architecture, Nemo-Nemo avoids the performance bottleneck inherent to single-leader protocols. By separating command dissemination from consensus logic, Nemo-Nemo handles challenging network conditions even when consensus commits are stalled. Moreover, leader proposals that miss a deadline are never dropped, but deterministically deferred and executed later, preserving throughput under transient network delays. And by enabling Nemo-Nemo to commit on a DAG in just two network hops, it matches the latency of existing CFT systems, while achieving significantly higher throughput. The result is a robust, deployable system: the first DAG-based CFT consensus protocol proven to exceed state-of-the-art wide-area network performance in both speed and resilience.

翻译：本文介绍Nemo-Nemo，一种实用的崩溃容错（CFT）共识协议，旨在通过融合CFT与拜占庭容错（BFT）领域的设计原则，在广域网中超越现有协议的性能。通过因果有序的DAG（有向无环图）结构来组织命令传播，Nemo-Nemo允许所有共识副本以天然自调节的通信机制提出命令。利用多领导者架构，Nemo-Nemo避免了单领导者协议固有的性能瓶颈。通过将命令分发与共识逻辑分离，Nemo-Nemo即使在共识提交停滞时也能应对苛刻的网络条件。此外，错过截止时间的领导者提议不会被丢弃，而是确定性地推迟并随后执行，从而在瞬态网络延迟下保持吞吐量。通过使Nemo-Nemo只需两跳网络即可在DAG上完成提交，该协议在匹配现有CFT系统延迟的同时，实现了显著更高的吞吐量。最终成果是一个鲁棒且可部署的系统：首个在速度和韧性上均被证明超越现有广域网性能的基于DAG的CFT共识协议。