Why This Matters

In Amazon RDS, two features often get confused:

They solve different problems.

What is Multi-AZ?

Multi-AZ (Multi-Availability Zone) keeps a synchronous standby database replica in another AZ.

Purpose: Failover & durability

Not meant for performance scaling.

Key Capabilities

When Multi-AZ Helps

Scenario Why Use
Production critical database Needs automatic failover
Financial, medical apps High uptime compliance
Unpredictable failures Secondary ready instantly
DB patching & maintenance Minimal downtime

How It Works

Primary DB ↔ Standby DB (sync)