AWS Certified SysOps Administrator – Associate — Question 389

A company is using an Amazon EC2 Auto Scaling group to support a workload. A SysOps administrator finds that the Auto Scaling group is configured with two similar scaling policies.

One scaling policy adds 5 instances when CPU utilization reaches 80%. The other scaling policy adds 10 instances when CPU utilization reaches 80%.

What will happen when CPU utilization reaches the 80% threshold?

Answer options

• A. Amazon EC2 Auto Scaling will add 5 instances.
• B. Amazon EC2 Auto Scaling will add 10 instances.
• C. Amazon EC2 Auto Scaling will add 15 instances.
• D. The Auto Scaling group will not scale because of conflicting policies.

Correct answer: B

Explanation

When multiple scaling policies are triggered at the same time, Amazon EC2 Auto Scaling evaluates all of them and executes the policy that provides the largest capacity change to ensure the workload has sufficient resources. In this scenario, adding 10 instances is the larger action compared to adding 5 instances, so the 10-instance policy is executed. Options A, C, and D are incorrect because Auto Scaling does not aggregate the policies, fail to scale, or choose the smaller increment.