Highly available Cloud SQL Postgres: Any downtime when adding a read replica?

Question

I have highly available CloudSQL Postgres instances. If I add read replicas to each one will it cause any downtime, will it require a restart? It is highly likely there is no restart at all, I could not find something clear on the GCP Cloud SQL documentation.

Answer 1

• According to Cloud SQL MySQL doc, if binary logging is not enabled then it requires a restart.
• Creating Cloud SQL replicas in Postgres and SQL server don't have this caveat