This research paper details FlexiRaft, a modified Raft consensus algorithm designed for Meta's petabyte-scale MySQL deployments. The core improvement is the introduction of flexible quorums, allowing configurable trade-offs between latency, throughput, and fault tolerance. Two quorum modes are presented: static and dynamic. The paper explores the algorithm's modifications, fault tolerance guarantees, experimental performance validation, and lessons learned from its production implementation. Finally, it compares FlexiRaft to other consensus algorithm variants and proposes avenues for future work.

https://www.cidrdb.org/cidr2023/papers/p83-yadav.pdf