AWS Certified Solutions Architect – Associate (SAA-C02) — Question 173

A company has an application that posts messages to Amazon SQS. Another application polls the queue and processes the messages in an I/O-intensive operation. The company has a service level agreement (SLA) that specifies the maximum amount of time that can elapse between receiving the messages and responding to the users. Due to an increase in the number of messages, the company has difficulty meeting its SLA consistently.
What should a solutions architect do to help improve the application's processing time and ensure it can handle the load at any level?

Answer options

• A. Create an Amazon Machine Image (AMI) from the instance used for processing. Terminate the instance and replace it with a larger size.
• B. Create an Amazon Machine Image (AMI) from the instance used for processing. Terminate the instance and replace it with an Amazon EC2 Dedicated Instance.
• C. Create an Amazon Machine image (AMI) from the instance used for processing. Create an Auto Scaling group using this image in its launch configuration. Configure the group with a target tracking policy to keep its aggregate CPU utilization below 70%.
• D. Create an Amazon Machine Image (AMI) from the instance used for processing. Create an Auto Scaling group using this image in its launch configuration. Configure the group with a target tracking policy based on the age of the oldest message in the SQS queue.

Correct answer: D

Explanation

The correct answer is D because implementing an Auto Scaling group that monitors the age of the oldest message in the SQS queue allows for dynamic scaling based on actual workload demands, ensuring timely processing. Options A and B do not address the scalability issue, and option C, while it suggests scaling, focuses on CPU utilization which may not directly correlate with message processing times.