Architecture of ZAB – ZooKeeper Atomic Broadcast protocol
ZooKeeper Atomic Broadcast (Zab) protocol
Dynamic Reconfiguration of Primary/Backup Clusters
ZooKeeper - A Reliable, Scalable Distributed Coordination System
https://www.instaclustr.com/apache-zookeeper-meets-the-dining-philosophers/
See attachment for the proof of correctness written for Zab (ZooKeeper Atomic Broadcast)