PG HA user documentation should describe data flows
It'd be useful to have a text description and/or diagram that explains what service connects to what service via what protocols.
eg:
- Application connects to pgbouncer on tcp port 6432
- pgbouncer connects to the active database server on tcp port 5432
- standby database servers connect to the active database on tcp port 5432
- database servers connect to the consul servers on PROTO port PORT
Followup up from https://gitlab.com/gitlab-org/build/team-tasks/issues/14#note_46630006