multi az

Multi-AZ is the answer and the reason matters more than the acronym. Each tier fails differently, and the database is the one where high availability means a failover with a real gap, not zero interruption.

Database redundancy still needs reconnecting clients. Distinguish the deployment type, then measure how promotion and DNS changes affect application requests.

Spreading instances across availability zones is not the same as surviving an AZ failure. What makes the difference is being able to name the four coupling points that quietly re-unify a blast radius you thought you had split.

Ask whether Multi-AZ means a DB instance or a DB cluster. One has a non-readable standby; the other has two readers. That distinction decides whether the proposal can relieve the primary.