“Optimize Private to Public Service Traffic in AWS: Reduce Latency and Costs”

Optimize Private to Public Service Traffic in AWS: Reduce Latency and Costs 🚀

In modern cloud architectures, seamless communication between services is critical to maintaining performance and cost efficiency. But what happens when your private and public services are communicating inefficiently, leading to increased latency and costs?

In this blog, we’ll explore:

• Current architecture challenges.

• The latency problem in private-to-public traffic.

• Three solutions to optimize your AWS architecture:

1. Placing the ALB in the same VPC as the backend.

2. Using ECS Service Discovery.

3. Leveraging AWS PrivateLink.

Let’s dive in!

Current Architecture: The Problem

Imagine you have two services:

• Service A(Backend):Running in a private VPC with NAT Gateway for internet access.

• Service B(Frontend):Running in AWS ECS, exposed publicly through an Application Load Balancer (ALB), and mapped to a domain like servb.test.com.

How it works: Service A connects to Service B via the public domain name (servb.test.com). Traffic flows through the NAT Gateway, the public ALB, and back to ECS containers hosting Service B.

The Challenge:

• Latency Issues: Traffic routing through the public internet introduces delays, often adding up to 2 seconds.

• Cost Concerns: Using a NAT Gateway incurs significant data processing costs, while the ALB adds its own charges for data transfer and processing.

The Goal: Optimize this architecture to reduce latency and costs without compromising performance or reliability.

Solution 1: Place the ALB in the Same VPC as the Backend ✅

How It Works:

Convert the ALB from a public-facing load balancer to an internal ALB by placing it in the same VPC as Service A. This keeps the traffic entirely within AWS’s private network.

Benefits:

• Reduces latency by eliminating public internet routing.

• Removes the need for NAT Gateway, significantly lowering costs.

• Traffic between Service A and Service B becomes more secure.

Implementation Steps:

1. Update the ALB configuration to change its scheme to internal.

2. Ensure both services (A and B) are in the same VPC and subnet.

3. Update DNS or service configurations to point Service A to the private ALB.

When to Use:

This is the most cost-effective and straightforward solution for latency reduction.

Solution 2: Use ECS Service Discovery ✅

How It Works:

AWS ECS supports Service Discovery, allowing ECS tasks to register themselves in a private Route 53 DNS namespace. Service A can directly resolve Service B’s private IP without going through the ALB.

Benefits:

• Further reduces latency by bypassing the ALB entirely for inter-service communication.

• Saves on ALB and NAT Gateway costs.

• Simplifies service-to-service communication with dynamic DNS updates.

Implementation Steps:

1. Enable Service Discovery in the ECS task definition for Service B.

2. Create a private DNS namespace (e.g., servb.local) using AWS Route 53.

3. Update Service A to use the new DNS name (servb.local) for Service B.

When to Use:

This is an excellent option when you don’t need the ALB for other public-facing clients and want to streamline service communication.

Solution 3: Use AWS PrivateLink 🚫

How It Works:

With AWS PrivateLink, you can create a VPC Interface Endpoint for Service B. Service A can then communicate with Service B via this private endpoint without traversing the internet.

Benefits:

• Provides a highly secure and private connection.

• Eliminates public traffic exposure entirely.

• Maintains stable and low latency.

Drawbacks:

• Cost: PrivateLink incurs hourly charges ($0.01 per hour) and data transfer fees ($0.01 per GB). This makes it more expensive than other options.

Implementation Steps:

1. Create a VPC Endpoint for the ALB using AWS PrivateLink.

2. Update the DNS configuration for Service A to point to the VPC Endpoint.

When to Use:

PrivateLink is ideal for compliance-heavy workloads where keeping traffic private is non-negotiable, despite higher costs.

Place ALB in the Same VPC ✅ Low ✅ Cost-Effective General use cases with inter-service communication.

ECS Service Discovery ✅ Lowest ✅ Cost-Effective Simplifying internal traffic flow between services.

AWS PrivateLink ✅ Low 🚫 Expensive Compliance or security-critical applications.

Conclusion

Reducing latency and optimizing costs in AWS is all about designing smarter architectures.

• For cost-effective and simple setups, placing the ALB in the same VPC or using ECS Service Discovery are excellent options.

• For high-security requirements, AWS PrivateLink provides a robust solution, albeit at a higher cost.

By implementing these strategies, you can improve your application’s performance while saving on unnecessary expenses.

Please find the complete video here:

🚀 Boost AWS Service Performance: Cut Latency Between Private and Public Traffic 🌐|#latency. #sre