AWS Certified Solutions Architect – Professional (SAP-C02) — Question 177

A solutions architect is designing a solution to process events. The solution must have the ability to scale in and out based on the number of events that the solution receives. If a processing error occurs, the event must move into a separate queue for review.

Which solution will meet these requirements?

Answer options

• A. Send event details to an Amazon Simple Notification Service (Amazon SNS) topic. Configure an AWS Lambda function as a subscriber to the SNS topic to process the events. Add an on-failure destination to the function. Set an Amazon Simple Queue Service (Amazon SQS) queue as the target.
• B. Publish events to an Amazon Simple Queue Service (Amazon SQS) queue. Create an Amazon EC2 Auto Scaling group. Configure the Auto Scaling group to scale in and out based on the ApproximateAgeOfOldestMessage metric of the queue. Configure the application to write failed messages to a dead-letter queue.
• C. Write events to an Amazon DynamoDB table. Configure a DynamoDB stream for the table. Configure the stream to invoke an AWS Lambda function. Configure the Lambda function to process the events.
• D. Publish events to an Amazon EventBndge event bus. Create and run an application on an Amazon EC2 instance with an Auto Scaling group that is behind an Application Load Balancer (ALB). Set the ALB as the event bus target. Configure the event bus to retry events. Write messages to a dead-letter queue if the application cannot process the messages.

Correct answer: B

Explanation

Option B is the correct choice as it utilizes Amazon SQS for event queuing, allows for automatic scaling based on the queue's metrics, and includes a dead-letter queue for failed messages. Option A does not provide the necessary scaling mechanism. Option C does not offer an effective way to handle processing errors with a separate queue. Option D complicates the architecture without addressing the scaling and error handling as effectively as option B.