It's really not documented well (and the generated docs are a joke) but from what I can gather, it's bog-standard PG replication with a go app to monitor the re

It's really not documented well (and the generated docs are a joke) but from what I can gather, it's bog-standard PG replication with a go app to monitor the replication and do automated failover. The monitor node appears to be there to act as neutral witness node so that a secondary is only promoted leader if it can reach the monitor and the monitor cannot reach the current leader. Hopefully, the leader also commits suicide when it cannot reach the monitor. MS SQL server implements this pattern and calls it "Database Mirroring Witness": https://msdn.microsoft.com/en-us/library/ms175191.aspx https://msdn.microsoft.com/en-us/library/ms175191.aspx