AWS Certified Solutions Architect – Professional (SAP-C02) — Question 216

A company operates quick-service restaurants. The restaurants follow a predictable model with high sales traffic for 4 hours daily. Sales traffic is lower outside of those peak hours.

The point of sale and management platform is deployed in the AWS Cloud and has a backend that is based on Amazon DynamoDB. The database table uses provisioned throughput mode with 100,000 RCUs and 80,000 WCUs to match known peak resource consumption.

The company wants to reduce its DynamoDB cost and minimize the operational overhead for the IT staff.

Which solution meets these requirements MOST cost-effectively?

Answer options

• A. Reduce the provisioned RCUs and WCUs.
• B. Change the DynamoDB table to use on-demand capacity.
• C. Enable Dynamo DB auto scaling for the table.
• D. Purchase 1-year reserved capacity that is sufficient to cover the peak load for 4 hours each day.

Correct answer: C

Explanation

Activating DynamoDB auto scaling allows the system to automatically adjust the provisioned throughput based on actual traffic, which can reduce costs during off-peak hours without requiring manual adjustments. The other options either reduce throughput too much (A), change to a pricing model that may not be as cost-effective for predictable traffic patterns (B), or commit to a fixed cost (D) which does not address the need for flexibility in resource allocation.