AWS Certified Solutions Architect – Professional (SAP-C02) — Question 143

An international delivery company hosts a delivery management system on AWS. Drivers use the system to upload confirmation of delivery. Confirmation includes the recipient’s signature or a photo of the package with the recipient. The driver’s handheld device uploads signatures and photos through FTP to a single Amazon EC2 instance. Each handheld device saves a file in a directory based on the signed-in user, and the file name matches the delivery number. The EC2 instance then adds metadata to the file after querying a central database to pull delivery information. The file is then placed in Amazon S3 for archiving.

As the company expands, drivers report that the system is rejecting connections. The FTP server is having problems because of dropped connections and memory issues in response to these problems, a system engineer schedules a cron task to reboot the EC2 instance every 30 minutes. The billing team reports that files are not always in the archive and that the central system is not always updated.

A solutions architect needs to design a solution that maximizes scalability to ensure that the archive always receives the files and that systems are always updated. The handheld devices cannot be modified, so the company cannot deploy a new application.

Which solution will meet these requirements?

Answer options

• A. Create an AMI of the existing EC2 instance. Create an Auto Scaling group of EC2 instances behind an Application Load Balancer. Configure the Auto Scaling group to have a minimum of three instances.
• B. Use AWS Transfer Family to create an FTP server that places the files in Amazon Elastic File System (Amazon EFS). Mount the EFS volume to the existing EC2 instance. Point the EC2 instance to the new path for file processing.
• C. Use AWS Transfer Family to create an FTP server that places the files in Amazon S3. Use an S3 event notification through Amazon Simple Notification Service (Amazon SNS) to invoke an AWS Lambda function. Configure the Lambda function to add the metadata and update the delivery system.
• D. Update the handheld devices to place the files directly in Amazon S3. Use an S3 event notification through Amazon Simple Queue Service (Amazon SQS) to invoke an AWS Lambda function. Configure the Lambda function to add the metadata and update the delivery system.

Correct answer: C

Explanation

Option C is the correct solution because it leverages AWS Transfer Family to create a reliable FTP server that integrates directly with Amazon S3, ensuring files are consistently archived. The use of S3 event notifications to trigger a Lambda function allows for automatic metadata addition and system updates, addressing the scalability issues. The other options either do not ensure the same level of reliability and scalability or involve changes to the handheld devices, which is not permitted.