AWS Certified Solutions Architect – Associate (SAA-C02) — Question 564

A company's website handles millions of requests each day, and the number of requests continues to increase. A solutions architect needs to improve the response time of the web application. The solutions architect determines that the application needs to decrease latency when retrieving product details from the
Amazon DynamoDB table.
Which solution will meet these requirements with the LEAST amount of operational overhead?

Answer options

• A. Set up a DynamoDB Accelerator (DAX) cluster. Route all read requests through DAX.
• B. Set up Amazon ElastiCache for Redis between the DynamoDB table and the web application. Route all read requests through Redis.
• C. Set up Amazon ElastiCache for Memcached between the DynamoDB table and the web application. Route all read requests through Memcached.
• D. Set up Amazon DynamoDB Streams on the table, and have AWS Lambda read from the table and populate Amazon ElastiCache. Route all read requests through ElastiCache.

Correct answer: A

Explanation

Amazon DynamoDB Accelerator (DAX) is a fully managed, in-memory cache designed specifically for DynamoDB that is API-compatible, requiring minimal application changes and the least operational overhead. In contrast, using Amazon ElastiCache (either Redis or Memcached) requires the developer to write custom application logic to manage cache population and invalidation. Utilizing DynamoDB Streams and AWS Lambda to populate ElastiCache adds even more architectural complexity and maintenance effort compared to the turn-key DAX solution.