High-Availability and Cost-Saving Recommendations for a Public Archives Application

Answer - A, B, and C.

Option A is CORRECT because CloudFront does the caching via the edge locations, reducing the load on the origin.

Option B is CORRECT because increasing the size of the images would help reduce the cost of the number of GET/PUT requests on the origin server.

Option C is CORRECT, INTELLIGENT_TIERING storage class is designed to optimize storage costs by automatically moving data to the most cost-effective storage access tier, without performance impact or operational overhead.

Option D is incorrect because decreasing the size would require more requests and will increase the overall cost.

Option E is incorrect because Glacier is an archival solution and will not be suitable for frequent access to the tiles.

The application displays scanned historical documents and needs to be highly available and cost-effective in production on AWS. The following recommendations can be considered:

A. Deploy an Amazon CloudFront distribution in front of the Amazon S3 tiles bucket: CloudFront is a content delivery network (CDN) that caches content at edge locations close to the user to improve application performance. Deploying CloudFront in front of an S3 tiles bucket can improve application performance by caching content and reducing the load on the S3 bucket. This can also reduce costs as the user will be accessing content from the nearest edge location rather than directly from the S3 bucket.

B. Increase the size (width/height) of the individual tiles at the maximum zoom level: Increasing the size of the individual tiles at the maximum zoom level can reduce the number of requests made to the S3 bucket and improve application performance. However, it can also increase the storage requirements and costs as larger tiles will require more storage space.

C. Use the S3 INTELLIGENT_TIERING storage class: The S3 INTELLIGENT_TIERING storage class automatically moves objects between two access tiers based on changing access patterns. This can help reduce costs as objects that are infrequently accessed are automatically moved to a lower cost tier. This can be beneficial in scenarios where there are periods of high activity followed by long periods of inactivity.

D. Decrease the size (width/height) of the individual tiles at the maximum zoom level: Decreasing the size of the individual tiles at the maximum zoom level can increase the number of requests made to the S3 bucket and improve application performance. However, it can also reduce storage requirements and costs as smaller tiles will require less storage space.

E. Store the maximum zoom level in the low-cost Amazon S3 Glacier option and only retrieve the most frequently accessed tiles as they are requested by users: Storing the maximum zoom level in the low-cost Amazon S3 Glacier option can reduce costs but can also increase the retrieval time. The most frequently accessed tiles can be stored in S3 standard or S3 INTELLIGENT_TIERING storage classes for faster retrieval. This can be beneficial if there is a large amount of infrequently accessed data that needs to be stored for compliance or regulatory purposes.

In summary, recommendations A, C, and E can help reduce costs while improving application performance and availability. Recommendations B and D can improve application performance but may increase storage requirements and costs.