Auto Scaling groups should use multiple instance types across multiple Availability Zones

Description

This check verifies that an Amazon EC2 Auto Scaling group uses more than one instance type. The check fails if the Auto Scaling group is configured with only one instance type.

To boost availability, it is recommended that you deploy your application on various instance types across multiple Availability Zones. Security Hub advocates for the use of several instance types, enabling the Auto Scaling group to initiate an alternative instance type should there be a lack of capacity in your selected Availability Zones.

Remediation

To pass this check please configure at least two different instance types across multiple availability zones. For guidance on setting up an Auto Scaling group with multiple instance types, refer to the section on Auto Scaling groups with multiple instance types and purchase options in the Amazon EC2 Auto Scaling user guide.