The high-availability design says an RDS Multi-AZ failover is typically one to two minutes, and that committed data survives an Availability Zone loss. That number is a planning figure from AWS documentation. It is not a measurement of your instance, your DNS cache, or your connection pool.

This is the drill I run to replace that figure with three timestamps: when RDS finishes the failover, when a new connection succeeds, and how far back a point-in-time restore can actually reach. It uses a disposable Multi-AZ DB instance. The RDS API calls are the same for MySQL. The client commands below are PostgreSQL.

Companion to Designing a Highly Available and Scalable Architecture on AWS .

Who this is for: Cloud operations and SRE people who already have a Multi-AZ design and want a repeatable test, with the commands, before they trust it in production.

Production note: Run this on an instance created for the drill, or on a non-production copy restored from a snapshot.…