AWS Route 53: Geoproximity Routing Policy

Introduction

Geoproximity Routing in Amazon Route 53 allows you to route traffic based on the geographic location of users and resources. Unlike Geolocation Routing, which strictly follows country-based rules, Geoproximity Routing enables traffic shifting between different locations using a feature called bias.

How Geoproximity Routing Works

1. Traffic Distribution by Location
   • Users are routed to the nearest AWS region or on-premises resource.
   • AWS determines proximity based on region (for AWS resources) or latitude/longitude (for on-premises resources).
2. Using Bias to Shift Traffic
   • Bias allows expanding or shrinking the influence of a location:
     • Positive Bias (+) → Expands the area, attracting more traffic.
     • Negative Bias (-) → Shrinks the area, reducing traffic.
3. Routing Customization with Traffic Flow
   • Geoproximity Routing requires Route 53 Traffic Flow to configure bias settings.

Example Scenarios

Scenario 1: Default Routing (No Bias)

• Two AWS resources:
  • us-west-1
  • us-east-1
• Bias = 0 for both regions.
• The U.S. is evenly divided:
  • West coast traffic goes to us-west-1.
  • East coast traffic goes to us-east-1.

Scenario 2: Traffic Shift with Bias

• Increase bias (+50) in us-east-1.
• The dividing line moves westward, meaning:
  • More users are routed to us-east-1.
  • Fewer users go to us-west-1.

📌 Use Cases for Bias:

• Direct more traffic to a powerful or underutilized resource.
• Shift traffic away from a region experiencing high load or outages.