What is the MOST cost-effective solution that meets these requirements?
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.
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.
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.
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.
Explanations:
Using a NAT instance incurs additional costs and management overhead. Additionally, moving logs to S3 Glacier is not suitable for logs that need to be quickly accessible for the first 90 days, as Glacier is designed for long-term archival storage with longer retrieval times.
Using an S3 sync job with a gateway VPC endpoint allows secure and cost-effective transfer of logs from the EC2 instances to S3 without needing a NAT gateway. The use of S3 Standard storage for the first 90 days meets the accessibility requirement, and moving logs older than 90 days to S3 Glacier Deep Archive optimizes cost for long-term storage.
S3 batch operations are not necessary for this scenario since a sync job is more efficient for continuous log uploads. Using a NAT gateway also incurs higher costs compared to using a VPC endpoint. The Glacier Deep Archive option is correct, but the overall approach is not optimal.
Although using a gateway VPC endpoint is correct, the sync job method is less suitable as logs generated at a high rate (100 MB/s) may not be handled efficiently. Moreover, it lacks the cost-effective aspect of moving logs to Glacier Deep Archive, which is essential for long-term storage.
I classify that the answer is:
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.