AWS Certified Solutions Architect – Professional — Question 672

A company runs a serverless application in a single AWS Region. The application accesses external URLs and extracts metadata from those sites. The company uses an Amazon Simple Notification Service (Amazon SNS) topic to publish URLs to an Amazon Simple Queue Service (Amazon SQS) queue. An AWS Lambda function uses the queue as an event source and processes the URLs from the queue. Results are saved to an Amazon S3 bucket.
The company wants to process each URL in other Regions to compare possible differences in site localization. URLs must be published from the existing Region.
Results must be written to the existing S3 bucket in the current Region.
Which combination of changes will produce multi-Region deployment that meets these requirements? (Choose two.)

Answer options

• A. Deploy the SQS queue with the Lambda function to other Regions.
• B. Subscribe the SNS topic in each Region to the SQS queue.
• C. Subscribe the SQS queue in each Region to the SNS topic.
• D. Configure the SQS queue to publish URLs to SNS topics in each Region.
• E. Deploy the SNS topic and the Lambda function to other Regions.

Correct answer: A, C

Explanation

To process the URLs in other Regions, the processing components consisting of the Amazon SQS queue and the AWS Lambda function must be deployed in those destination Regions. By subscribing the newly deployed SQS queues in each target Region to the original central SNS topic, a fan-out pattern is created where messages are automatically replicated to all regions for processing. The regional Lambda functions can easily write their results back to the central S3 bucket in the primary region, satisfying all requirements.