AWS Certified Solutions Architect – Professional — Question 782
A company recently deployed an application on AWS. The application uses Amazon DynamoDB. The company measured the application load and configured the RCUs and WCUs on the DynamoDB table to match the expected peak load. The peak load occurs once a week for a 4-hour period and is double the average load. The application load is close to the average load for the rest of the week. The access pattern includes many more writes to the table than reads of the table.
A solutions architect needs to implement a solution to minimize the cost of the table.
Which solution will meet these requirements?
Answer options
- A. Use AWS Application Auto Scaling to increase capacity during the peak period. Purchase reserved RCUs and WCUs to match the average load.
- B. Configure on-demand capacity mode for the table.
- C. Configure DynamoDB Accelerator (DAX) in front of the table. Reduce the provisioned read capacity to match the new peak load on the table.
- D. Configure DynamoDB Accelerator (DAX) in front of the table. Configure on-demand capacity mode for the table.
Correct answer: A
Explanation
Using AWS Application Auto Scaling combined with reserved capacity is the most cost-effective option because the workload has a predictable baseline and a scheduled weekly peak. On-demand mode is more expensive for highly predictable workloads, and DynamoDB Accelerator (DAX) is designed for read-heavy workloads, making it ineffective and unnecessarily costly for this write-heavy application.