AWS Certified Solutions Architect – Professional — Question 678

A solutions architect needs to deploy an application on a fleet of Amazon EC2 Instances. The EC2 instances run in private subnets in an Auto Scaling group. The application is expected to generate logs at a rate of 100 MB each second on each of the EC2 instances.
The logs must be stored in an Amazon S3 bucket so that an Amazon EMR cluster can consume them for further processing. The logs must be quickly accessible for the first 90 days and should be retrievable within 48 hours thereafter.
What is the MOST cost-effective solution that meets these requirements?

Answer options

• A. Set up an S3 copy job to write logs from each EC2 instance to the S3 bucket with S3 Standard storage. Use a NAT instance within the private subnets to connect to Amazon S3. Create S3 Lifecycle policies to move logs that are older than 90 days to S3 Glacier.
• B. Set up an S3 sync job to copy logs from each EC2 instance to the S3 bucket with S3 Standard storage. Use a gateway VPC endpoint for Amazon S3 to connect to Amazon S3. Create S3 Lifecycle policies to move logs that are older than 90 days to S3 Glacier Deep Archive.
• C. Set up an S3 batch operation to copy logs from each EC2 instance to the S3 bucket with S3 Standard storage. Use a NAT gateway with the private subnets to connect to Amazon S3. Create S3 Lifecycle policies to move logs that are older than 90 days to S3 Glacier Deep Archive.
• D. Set up an S3 sync job to copy logs from each EC2 instance to the S3 bucket with S3 Standard storage. Use a gateway VPC endpoint for Amazon S3 to connect to Amazon S3. Create S3 Lifecycle policies to move logs that are older than 90 days to S3 Glacier.

Correct answer: B

Explanation

Using a gateway VPC endpoint is the most cost-effective way to connect EC2 instances in private subnets to Amazon S3, as it avoids the data processing charges associated with NAT gateways or NAT instances. To meet the 48-hour retrieval requirement, S3 Glacier Deep Archive is the most economical storage tier, offering standard retrievals within 12 hours. S3 Glacier is more expensive than Glacier Deep Archive and is unnecessary given the generous 48-hour retrieval window.