AWS Route 53: Failover Routing Policy

Introduction

The Failover Routing Policy in Amazon Route 53 ensures high availability by automatically switching traffic from a primary resource to a secondary (disaster recovery) resource when the primary becomes unhealthy. This is achieved by associating health checks with DNS records.

How Failover Routing Works

1. Primary and Secondary Setup:
   • Route 53 contains a primary DNS record pointing to a primary EC2 instance.
   • A secondary DNS record points to a backup EC2 instance.
2. Health Check Association:
   • The primary record must be associated with a Route 53 health check.
   • If the health check fails (instance becomes unreachable), Route 53 automatically fails over to the secondary record.
3. Automatic DNS Resolution:
   • When a client makes a DNS request, Route 53 responds with the healthy resource.
   • If the primary instance is healthy, Route 53 returns the primary IP.
   • If the primary fails, Route 53 switches to the secondary automatically.

Configuring Failover Routing in Route 53

Step 1: Create a Primary Failover Record

1. Go to Route 53 → Hosted Zones.
2. Click Create Record.
3. Set Record Name:
   • Example: failover.stephanetheteacher.com
4. Choose Record Type:
   • A Record (for EC2 instance IP)
5. Set the Value:
   • Example: IP of EU-central-1 instance
6. Choose Routing Policy:
   • Failover
7. Set Failover Record Type:
   • Primary
8. Associate with a Health Check:
   • Example: EU-central-1 Health Check
9. Set TTL (Time to Live):
   • Example: 60 seconds