AWS Certified SysOps Administrator – Associate — Question 243

ASysOps administrator configures an application to run on Amazon EC2 instances behind an Application Load Balancer (ALB) in a simple scaling Auto Scaling group with the default settings. The Auto Scaling group is configured to use the RequestCountPerTarget metric for scaling. The SysOps administrator notices that the RequestCountPerTarget metric exceeded the specified limit twice in 180 seconds.

How will the number of EC2 instances in this Auto Scaling group be affected in this scenario?

Answer options

• A. The Auto Scaling group will launch an additional EC2 instance every time the RequestCountPerTarget metric exceeds the predefined limit.
• B. The Auto Scaling group will launch one EC2 instance and will wait for the default cooldown period before launching another instance.
• C. The Auto Scaling group will send an alert to the ALB to rebalance the traffic and not add new EC2 instances until the load is normalized.
• D. The Auto Scaling group will try to distribute the traffic among all EC2 instances before launching another instance.

Correct answer: B

Explanation

The correct answer is B because the Auto Scaling group, by default, adds one EC2 instance and waits for a cooldown period before making further adjustments. Option A is incorrect, as it suggests continuous instance launches without regard for cooldown. Option C misinterprets the Auto Scaling behavior, which does not involve alerting the ALB for traffic management. Option D is also wrong because the Auto Scaling group does not prioritize traffic distribution before launching additional instances.