AWS Certified Solutions Architect – Associate (SAA-C03) — Question 777

A company uses high concurrency AWS Lambda functions to process a constantly increasing number of messages in a message queue during marketing events. The Lambda functions use CPU intensive code to process the messages. The company wants to reduce the compute costs and to maintain service latency for its customers.

Which solution will meet these requirements?

Answer options

• A. Configure reserved concurrency for the Lambda functions. Decrease the memory allocated to the Lambda functions.
• B. Configure reserved concurrency for the Lambda functions. Increase the memory according to AWS Compute Optimizer recommendations.
• C. Configure provisioned concurrency for the Lambda functions. Decrease the memory allocated to the Lambda functions.
• D. Configure provisioned concurrency for the Lambda functions. Increase the memory according to AWS Compute Optimizer recommendations.

Correct answer: D

Explanation

Provisioned concurrency ensures that Lambda functions are pre-warmed to eliminate cold start latencies during high-traffic events. Additionally, because AWS Lambda allocates CPU power proportionally to the configured memory, increasing memory based on AWS Compute Optimizer recommendations allows CPU-intensive code to run faster, which reduces overall execution duration and lowers compute costs. Reserved concurrency only limits maximum scale and does not prevent cold starts, while decreasing memory would degrade performance and increase execution time.