SAA-C03 Question #216: Real Exam Question with Answer & Explanation

Question

A company wants to create a payment processing application. The application must run when a payment record arrives in an existing Amazon S3 bucket. The application must process each payment record exactly once. The company wants to use an AWS Lambda function to process the payments. Which solution will meet these requirements?

Options

• AConfigure the existing S3 bucket to send object creation events to Amazon EventBridge.
• BConfigure the existing S3 bucket to send object creation events to an Amazon Simple Notification
• CConfigure the existing S3 bucket to send object creation events to an Amazon Simple Queue
• DConfigure the existing S3 bucket to send object creation events directly to the Lambda function.

Explanation

Configure an AWS Lambda function to process S3 payment records exactly once upon arrival.

Common mistakes.

• A. Amazon EventBridge also offers at-least-once delivery and requires idempotency in the Lambda function for 'exactly once' processing, similar to SNS, but SNS is a direct and common fan-out destination for S3 events.
• C. Sending S3 events to an Amazon SQS queue also requires idempotency in the Lambda function to achieve 'exactly once' processing, and while robust for message retention and retries, SNS is a common fan-out pattern for S3 to multiple targets.
• D. Configuring S3 to invoke a Lambda function directly also provides at-least-once delivery, requiring the Lambda function to implement idempotency for 'exactly once' processing, and lacks the fan-out or buffering capabilities of SNS or SQS.

Concept tested. S3 Event Notifications, Lambda idempotency, SNS

Reference. https://docs.aws.amazon.com/AmazonS3/latest/userguide/NotificationHowTo.html

No community discussion yet for this question.