I think we should have documentation about options to have HA in the system DB.

We already have something similar for Redis, the DB used by the backend component: https://access.redhat.com/documentation/en-us/red_hat_3scale_api_management/2.9/html/installing_3scale/redis-high-availability-support-for-threescale

There might be others, but at least we should mention these two options:

• Amazon RDS: https://aws.amazon.com/es/rds/ha/
• Crunchy DB (has an operator and can be installed on-premises). This doc explains how HA works in Crunchy: https://access.crunchydata.com/documentation/postgres-operator/latest/architecture/high-availability/