AWS Certified Solutions Architect – Professional — Question 392

Your firm has uploaded a large amount of aerial image data to S3. In the past, in your on-premises environment, you used a dedicated group of servers to oaten process this data and used Rabbit MQ - An open source messaging system to get job information to the servers. Once processed the data would go to tape and be shipped offsite. Your manager told you to stay with the current design, and leverage AWS archival storage and messaging services to minimize cost.
Which is correct?

Answer options

• A. Use SQS for passing job messages use Cloud Watch alarms to terminate EC2 worker instances when they become idle. Once data is processed, change the storage class of the S3 objects to Reduced Redundancy Storage.
• B. Setup Auto-Scaled workers triggered by queue depth that use spot instances to process messages in SOS Once data is processed, change the storage class of the S3 objects to Reduced Redundancy Storage.
• C. Setup Auto-Scaled workers triggered by queue depth that use spot instances to process messages in SQS Once data is processed, change the storage class of the S3 objects to Glacier.
• D. Use SNS to pass job messages use Cloud Watch alarms to terminate spot worker instances when they become idle. Once data is processed, change the storage class of the S3 object to Glacier.

Correct answer: C

Explanation

Amazon SQS is the ideal managed queue service to replace RabbitMQ, and using Auto Scaling with Spot Instances triggered by queue depth provides the most cost-effective processing for non-time-critical workloads. To replicate the offsite tape backup while minimizing costs, S3 Glacier is the correct archival storage class. Reduced Redundancy Storage (RRS) is not designed for archival storage and is more expensive than Glacier, while SNS is a pub/sub notification service rather than a message queuing system.