AWS Certified Developer – Associate (DVA-C02) — Question 397

A developer is creating an application that must transfer expired items from Amazon DynamoDB to Amazon S3. The developer sets up the DynamoDB table to automatically delete items after a specific TTL. The application must process the items in DynamoDB and then must store the expired items in Amazon S3. The entire process, including item processing and storage in Amazon S3, will take 5 minutes.

Which solution will meet these requirements with the LEAST operational overhead?

Answer options

• A. Configure DynamoDB Accelerator (DAX) to query for expired items based on the TTL. Save the results to Amazon S3.
• B. Configure DynamoDB Streams to invoke an AWS Lambda function. Program the Lambda function to process the items and to store the expired items in Amazon S3.
• C. Deploy a custom application on an Amazon Elastic Container Service (Amazon ECS) cluster on Amazon EC2 instances. Program the custom application to process the items and to store the expired items in Amazon S3.
• D. Create an Amazon EventBridge rule to invoke an AWS Lambda function. Program the Lambda function to process the items and to store the expired items in Amazon S3.

Correct answer: B

Explanation

When DynamoDB TTL deletes an item, it writes a delete record to DynamoDB Streams. Triggering a Lambda function from this stream is the most operationally efficient, serverless way to process these deletions and save them to Amazon S3, especially since the 5-minute processing time is well within Lambda's 15-minute execution limit. Using ECS on EC2 introduces significant management overhead, while DAX is for caching and EventBridge does not natively capture DynamoDB TTL deletions without streams.