Ensure we have a complete monitoring package for GitLab HA

As we introduce GitLab HA, we should ensure we have a complete monitoring story around it as well. This would include:

  • Ensuring we monitor all Redis, Postgres, and nginx instances.
  • Add monitoring for any extra services that are necessary like pgbouncer or repmgr.
  • Provide any higher level metrics that would be missing, such as frequency of failovers, etc.
Edited by silv