1. 2008. Apache ZooKeeper. https://zookeeper.apache.org/
2. 2012. ZooKeeper#1: Leader election never settles for a 5-node cluster. https://issues.apache.org/jira/browse/ZOOKEEPER-1419
3. 2013. WRaft. https://github.com/willemt/raft
4. 2016. An incorrect unit test in WRaft. https://github.com/willemt/raft/blob/e428eeb921a014192d1d703dd317f3f29f5916c5/tests/test_snapshotting.c#L498
5. 2016. DaosRaft. https://github.com/daos-stack/raft