Evaluate Omnibus Postgres HA for Praefect recommendations
Initial testing in gitlab-org/omnibus-gitlab#5919 (comment 760504276) suggests Omnibus Postgres can now support HA for Praefect (via Consul + PgBouncer).
As this is very desirable for the Reference Architectures we should evaluate the available options for what we should recommend for users.
There's several ways this can be tackled along with several considerations. The primary one being for Geo a separate Database instance appears to be required to avoid replication between sites. This will require it's own PgBouncer cluster currently but it should be able to use the same Consul cluster.
Task is to explore options and draw up recommendations.
Update - 2022-11-03
After the awesome groundwork done in gitlab-org&7814 (closed) I've been testing this out.
It looks like there's a little bit more to go for HA support in Omnibus for the Praefect and Geo databases. Have raised an issue with distribution here with the details.