Question #618
A company is developing a media upload service on AWS. When a user uploads a media file, the application processes the file and makes it available within 30 minutes. Processed files should be accessible for 24 hours. Some files exceed 5 MB in size. Each file is unique to the user. The application must delete all files older than 7 days. Which solution meets these requirements with the LEAST operational overhead?
Process the files and store them as Amazon DynamoDB items with a configured TTL. Generate a URL to retrieve the files from DynamoDB. Provide the URL to users through the application.
Process the files and store them in an Amazon S3 bucket with server-side encryption. Attach the files to an Amazon SNS message. Subscribe users to email notifications via SNS.
Process the files and store them in an Amazon RDS database with a timestamp. Generate a URL to retrieve the files from RDS. Provide the URL to users through the application. Schedule a daily Lambda function to delete records older than 7 days.
Process the files and store them in an Amazon S3 bucket with server-side encryption. Generate a presigned URL with a 24-hour expiration. Provide the URL to users through the application. Configure S3 Lifecycle rules to delete objects older than 7 days.
Explanation
Option D is correct because:
1. Amazon S3 efficiently stores large files (over 5 MB) and supports server-side encryption for security.
2. Presigned URLs provide time-limited access (24 hours) without exposing the bucket publicly.
3. S3 Lifecycle rules automatically delete objects after 7 days, requiring no manual intervention.
Other options fail due to:
- A: DynamoDB's 400KB item limit makes it unsuitable for files >5MB.
- B: SNS cannot handle large file attachments (>256KB), and lacks automated deletion.
- C: RDS is inefficient for large media files, and manual Lambda deletion adds operational overhead.
Key Points:
- Use S3 for large, transient storage.
- Presigned URLs grant temporary access.
- Lifecycle rules automate deletion, reducing management effort.
Answer
The correct answer is: D