When should we use AWS PrivateLink?
A large part of efficiently hosting workloads in the AWS cloud is choosing the right cloud network topology to optimize for cost, latency, and security. AWS PrivateLink offers a way to enhance security and reduce costs by providing private connectivity between Virtual Private Clouds (VPCs), AWS services, and on-premises networks. This article explores the cost-saving potential of AWS PrivateLink, providing common use cases with a cost comparison, while also outlining best practices for maximizing these savings.
Understanding AWS PrivateLink
AWS PrivateLink is a networking service that enables private connectivity between VPCs and AWS services, as well as third-party services, without exposing traffic to the public internet. By leveraging PrivateLink, organizations can achieve secure, private, and efficient communication between their resources.
How does PrivateLink work?
PrivateLink uses Elastic Network Interfaces (ENIs) to create endpoints in your VPC. These endpoints serve as private entry points to access supported AWS services and third-party services. Traffic routed through PrivateLink stays within the AWS network, ensuring lower latency, improved security, and potential cost savings.
Benefits of AWS PrivateLink
- Reduced Data Transfer Costs
- By keeping traffic within the AWS network, PrivateLink helps reduce data transfer costs, which can be significant when using the internet for communication between services.
- Eliminated NAT Gateway Costs
- PrivateLink eliminates the need for NAT gateways in scenarios where private access to AWS services is required, saving costs associated with NAT gateway usage.
- Enhanced Security
- Traffic through PrivateLink does not traverse the public internet, reducing exposure to potential threats and improving overall security posture.
- Simplified Network Architecture
- PrivateLink simplifies network architecture by eliminating the need for complex configurations such as direct connections, which can also contribute to cost savings.
Use Case
Consider a scenario where an organization has multiple EC2 instances in a private subnet that need to access Amazon S3 for storing and retrieving data. Without PrivateLink, these instances would require a NAT gateway for internet access. With PrivateLink, the organization can create an S3 VPC endpoint to enable private access to S3, eliminating the need for a NAT gateway.
Cost Breakdown
Without PrivateLink
- NAT Gateway Costs:
- Hourly Charge: $0.045 per hour
- Data Processing Charge: $0.045 per GB
- Data Transfer Costs:
- Data Transfer Out to the Internet: $0.09 per GB for the first 10 TB per month
Assume 5,000 hours of NAT gateway usage per month and 10 TB of data transfer:
- NAT Gateway Hourly Charge: 5,000 hours x $0.045 = $225
- NAT Gateway Data Processing Charge: 10,000 GB x $0.045 = $450
- Data Transfer Out to the Internet: 10,000 GB x $0.09 = $900
Total Monthly Cost without PrivateLink: $225 + $450 + $900 = $1,575
With PrivateLink
- PrivateLink VPC Endpoint Costs:
- Hourly Charge: $0.01 per hour
- Data Processing Charge: $0.01 per GB
- Data Transfer Costs:
- Data Transfer Within AWS: Typically free or significantly lower than internet data transfer
Assume 5,000 hours of VPC endpoint usage and 10 TB of data transfer:
- VPC Endpoint Hourly Charge: 5,000 hours x $0.01 = $50
- VPC Endpoint Data Processing Charge: 10,000 GB x $0.01 = $100
- Data Transfer Within AWS: $0 (Assuming free intra-region transfer)
Total Monthly Cost with PrivateLink: $50 + $100 = $150
Analysis of Savings
- Total Savings: $1,575 (without PrivateLink) - $150 (with PrivateLink) = $1,425
- Percentage Savings: ($1,425 / $1,575) x 100 = 90.5%
Using AWS PrivateLink in this scenario results in a 90.5% reduction in costs, demonstrating significant savings.
Additional Cost-Saving Strategies with PrivateLink
- Consolidating VPC Endpoints
- Create shared VPC endpoints that can be used by multiple services or accounts within the same region to further reduce costs.
- Optimizing Data Transfer
- Minimize data transfer by keeping traffic within the same region and utilizing PrivateLink for cross-account communication.
- Implementing Security Best Practices
- Ensure security groups and IAM policies are properly configured to avoid unnecessary data transfer and additional costs.
Conclusion
AWS PrivateLink offers a robust solution for enhancing security and achieving significant cost savings. By keeping traffic within the AWS network, PrivateLink reduces data transfer and NAT gateway costs, simplifies network architecture, and improves security. The use case presented demonstrates substantial savings, emphasizing the value of implementing PrivateLink in your AWS environment. By following best practices and continually monitoring costs, organizations can maximize the benefits of AWS PrivateLink and optimize their cloud spending.