AWS Certified Solutions Architect – Professional (SAP-C02) — Question 281

An entertainment company recently launched a new game. To ensure a good experience for players during the launch period, the company deployed a static quantity of 12 r6g.16xlarge (memory optimized) Amazon EC2 instances behind a Network Load Balancer. The company's operations team used the Amazon CloudWatch agent and a custom metric to include memory utilization in its monitoring strategy.

Analysis of the CloudWatch metrics from the launch period showed consumption at about one quarter of the CPU and memory that the company expected. Initial demand for the game has subsided and has become more variable. The company decides to use an Auto Scaling group that monitors the CPU and memory consumption to dynamically scale the instance fleet. A solutions architect needs to configure the Auto Scaling group to meet demand in the most cost-effective way.

Which solution will meet these requirements?

Answer options

Correct answer: C

Explanation

Because the application's performance profile is memory-intensive, it is best to stick with the memory-optimized r6g family rather than switching to compute-optimized (c6g) or general-purpose (m6g) instances. Since actual utilization was only 25% (one-quarter) of the original setup, scaling down from 16xlarge to 4xlarge (which is exactly one-quarter of the size) is the most cost-effective starting point. Configuring a minimum and desired capacity of 3 r6g.4xlarge instances matches the baseline 25% resource requirements of the original 12 r6g.16xlarge instances while allowing the Auto Scaling group to scale up to 12 instances as demand fluctuates.