A document-processing server on Linux generates and modifies files at about 5 documents per second and needs fast local filesystem performance. Many applications were updated to use the S3 API, but this processing server cannot be updated immediately. After processing completes, files must be publicly available from S3 within 30 minutes. Which option meets the requirement with the least effort?

The S3 File Gateway allows the Linux server to interact with S3 using standard file protocols like NFS, eliminating the need to refactor the application. It caches frequently accessed data locally for fast performance and asynchronously uploads changes to S3. The RefreshCache API ensures that changes made directly in S3 are reflected on the gateway within the 30-minute requirement. Refactoring to Lambda is a significant effort and not an immediate solution. FSx for Lustre is a high-performance file system, but it's more complex and potentially overkill for this use case, and its import/export configuration adds management overhead. AWS DataSync is designed for large-scale, one-time or scheduled data transfers, not for continuous, real-time file system access from an application.