Single-AZ Cluster Check

Rule Details

Application Scenarios

An AZ is a physical location that uses independent power supply and networks. AZs in the same region can communicate with each other over an intranet. If your workloads require cross-AZ DR or are insensitive to cross-AZ latency, you are advised to deploy the primary node and read replicas in different AZs to achieve higher availability and reliability.

You can deploy primary and standby instances in a single AZ or across AZs to achieve failover and high availability.

Solution

When purchasing an RDS for MySQL instance, purchasing an RDS for PostgreSQL instance, or other types of databases, select multiple AZs.

If the primary and standby DB instances are already in the same AZ, change the AZ of the standby DB instance.

Rule Logic

• If an RDS DB instance is deployed in a single AZ, this instance is non-compliant.
• If an RDS DB instance is deployed across AZs, this instance is compliant.