An enterprise operates a multi-VPC architecture in the `eu-west-1` Region. An ETL applicat… — AWS Certified Solutions Architect - Associate

An enterprise operates a multi-VPC architecture in the `eu-west-1` Region. An ETL application running on Amazon EC2 instances in VPC A (Production) regularly extracts large datasets from an RDS MySQL database and transfers $120\text{ TB}$ of data monthly to an Amazon Redshift cluster in VPC B (Analytics). Currently, all inter-VPC traffic is routed through an AWS Transit Gateway. A solutions architect is tasked with optimizing the network design to reduce monthly data transfer costs without introducing network performance bottlenecks. Which routing strategy is the most cost-effective?

Establish a VPC Peering connection between VPC A and VPC B, and update the route tables in both VPCs to route the database traffic through the peering connection.Answer
B
Deploy NAT Gateways in the private subnets of VPC A and VPC B, and configure the application to transfer the data over the public internet.
C
Configure an AWS Site-to-Site VPN connection between the two VPCs using Virtual Private Gateways, and route the database traffic through the IPsec tunnels.
D
Create an AWS PrivateLink endpoint service for the Amazon Redshift cluster in VPC B, and provision an interface VPC endpoint in VPC A to transfer the data.

Answer

Establish a VPC Peering connection between VPC A and VPC B, and update the route tables in both VPCs to route the database traffic through the peering connection.

Establishing a VPC Peering connection directly between VPC A and VPC B is the most cost-effective solution. VPC Peering does not charge hourly fees or data processing fees. It only charges standard intra-region data transfer rates (which are free within the same Availability Zone or cost

0.01 per GB in each direction across different Availability Zones). By routing the

120\text{ TB}

of data through a VPC Peering connection instead of AWS Transit Gateway, the company avoids the

0.02 per GB Transit Gateway data processing fee, saving

\$2,400

monthly.

Step-by-Step Solution

Analyze the current architecture and identify the cost drivers.

Current data transfer of

120\text{ TB}

(

120,000\text{ GB}

) over AWS Transit Gateway incurs a data processing fee of

0.02\text{ per GB}

in `eu-west-1`, resulting in

120,000 \times 0.02 = \$2,400

per month in processing charges alone (excluding attachment fees).

Understanding the cost breakdown of the current architecture allows us to identify the primary driver of high network expenses.

Evaluate alternative inter-VPC routing options in terms of data processing cost, hourly fees, and throughput limits.

VPC Peering charges

\$0\text{ per GB}

for data processing. AWS PrivateLink charges

\$0.01\text{ per GB}

for data processing. NAT Gateways charge

\$.045\text{ per GB}

for data processing. Site-to-Site VPN is limited to

1.25\text{ Gbps}

per tunnel and incurs internet egress fees.

Comparing the processing costs and performance constraints of each service helps determine which routing mechanism minimizes overhead.

Select the option that eliminates data processing fees without introducing bandwidth constraints.

VPC Peering is selected because it completely bypasses the Transit Gateway's data processing fee and provides unconstrained line-rate performance between the two VPCs.

VPC Peering offers direct, private connectivity with no processing fee, making it the most cost-effective and highest-performing routing choice.

Key Concept

Selecting the most cost-effective network routing mechanism based on data volume, where VPC Peering is preferred over AWS Transit Gateway and AWS PrivateLink for high-volume traffic due to the absence of per-GB data processing fees.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

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