Examkin

Question

Difficulty: Very hardManaging Storage and Data Transfer Costs

An enterprise runs a distributed data processing application in Account A. The application runs on Amazon EC2 instances in a VPC in the us−west−2us-west-2 (Oregon) Region across three Availability Zones. Every month, the EC2 instances retrieve 600 TB600\text{ TB} of raw telemetry data from an Amazon S3 bucket located in the us−west−2us-west-2 Region in Account B (Shared Services). After processing, the application writes 150 TB150\text{ TB} of transformed data to a central analytics S3 bucket in the us−east−1us-east-1 (N. Virginia) Region in Account C (Analytics).

Currently, the VPC in Account A has a single NAT Gateway in one Availability Zone. All traffic to S3 is routed through this NAT Gateway. A Solutions Architect notices that the monthly AWS bill shows extremely high NAT Gateway data processing charges and inter-Region data transfer costs. The company wants to minimize these costs while maintaining a secure and highly available architecture.

Which configuration is the most cost-effective and architecturally sound?

  1. A
    Configure an Amazon S3 Interface VPC Endpoint (AWS PrivateLink) in each Availability Zone in Account A's VPC. Configure the application to route all S3 traffic (both downloads from Account B and uploads to Account C) through these Interface VPC Endpoints to bypass the NAT Gateway.
  2. B
    Configure an Amazon S3 Gateway VPC Endpoint in Account A's VPC and associate it with the route tables for all three Availability Zones. Create a local S3 staging bucket in us−west−2us-west-2 in Account A, and configure an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive after 24 hours. Configure the application to write the transformed data directly to the S3 bucket in us−east−1us-east-1 via a VPC Peering connection established between Account A and Account C.
  3. Configure an Amazon S3 Gateway VPC Endpoint in Account A's VPC and associate it with the route tables for all three Availability Zones. Create a local S3 staging bucket in us−west−2us-west-2 in Account A. Configure the application to write the transformed data to the local staging bucket, and use an S3 Lifecycle policy to delete the objects after 1 day. Enable S3 Cross-Region Replication (CRR) on the staging bucket to replicate the processed data to the destination S3 bucket in us−east−1us-east-1 in Account C.Answer
  4. D
    Deploy a NAT Gateway in each of the three Availability Zones in Account A's VPC to ensure high availability. For the 150 TB150\text{ TB} of processed data, write the output to a local AWS Snowball Edge Storage Optimized device positioned in the local data center, and physically ship it to the AWS analytics center in us−east−1us-east-1 weekly to eliminate all inter-Region network data transfer charges.

Answer

Configure an Amazon S3 Gateway VPC Endpoint in Account A's VPC across all route tables. Save the processed data to a local staging S3 bucket in us−west−2us-west-2, and use S3 Cross-Region Replication (CRR) to replicate the data to us−east−1us-east-1 in Account C, using an S3 Lifecycle policy to delete the local staging objects after 1 day.
The correct configuration uses an S3 Gateway VPC Endpoint to route all local S3 traffic (downloads from the raw bucket and uploads to the staging bucket) directly to S3 without passing through the NAT Gateway, costing 00 in data processing fees. By utilizing S3 Cross-Region Replication (CRR) from the staging bucket in us−west−2us-west-2 to the destination bucket in us−east−1us-east-1, the data transfer is managed entirely within the S3 service. This avoids NAT Gateway data processing charges for the cross-Region write, while keeping inter-Region transfer costs identical to direct uploads. The 1-day S3 Lifecycle expiration policy ensures staging data is cleaned up immediately, preventing unnecessary storage charges.

Step-by-Step Solution

1
Address the local S3 read costs (600 TB600\text{ TB}).
Create an S3 Gateway VPC Endpoint in Account A and associate it with all subnet route tables.
Gateway Endpoints are free and route traffic directly to S3 within the same Region, saving 600 TB×1024 GB/TB×$0.045/GB=$27,648600\text{ TB} \times 1024\text{ GB/TB} \times \$0.045/\text{GB} = \$27,648 per month in NAT Gateway processing fees.
2
Address the cross-Region S3 write costs (150 TB150\text{ TB}).
Avoid writing directly to us−east−1us-east-1 via NAT Gateway, which would cost 150 TB×1024 GB/TB×$0.045/GB=$6,912150\text{ TB} \times 1024\text{ GB/TB} \times \$0.045/\text{GB} = \$6,912 in processing fees.
Gateway VPC Endpoints only route traffic to S3 buckets in the same Region. Writing directly to another Region's S3 bucket bypasses the Gateway Endpoint and goes through the NAT Gateway.
3
Optimize the cross-Region data path using S3 staging and replication.
Upload processed data to a staging bucket in us−west−2us-west-2 via the Gateway VPC Endpoint, and configure S3 Cross-Region Replication (CRR) to replicate it to the destination bucket in us−east−1us-east-1.
The upload to the local staging bucket incurs no data processing fees due to the Gateway Endpoint. S3 CRR replicates the data directly from S3 us−west−2us-west-2 to S3 us−east−1us-east-1, bypassing the VPC's NAT Gateway entirely and avoiding the processing charges, while only charging standard inter-Region data transfer rates.
4
Configure storage cleanup.
Add an S3 Lifecycle rule to the local staging bucket to expire/delete objects after 1 day.
This prevents duplicate storage costs in the source Region while ensuring enough time for replication to complete successfully.

Key Concept

Bypassing NAT Gateway data processing charges for cross-Region S3 access by writing to a local S3 staging bucket via a Gateway Endpoint and utilizing S3 Cross-Region Replication (CRR).

Alternative Method

If CRR is not desired, another option would be to write the data to an EC2 instance hosted in the destination region via a VPC Peering connection, and have that instance upload the data to the destination S3 bucket. However, this introduces extra compute costs, management overhead, and potential performance bottlenecks compared to native S3 CRR.
Estimated Time:3m 0s
Rate this question

Topics

Managing Storage and Data Transfer Costs