Configure AWS Route 53 weighted routing and failover routing with health checks

Steps

1. Create a hosted zone for your domain in Route 53 (or use an existing one); update your registrar's nameserver records to point to the Route 53 NS records if the domain is registered elsewhere
2. For weighted routing, create multiple records with the same name and type, each with a distinct Weight value (0–255) and a unique SetIdentifier; Route 53 distributes traffic proportionally based on weights — set Weight=0 to stop sending traffic to a record without deleting it
3. For failover routing, create a PRIMARY and SECONDARY record for the same name with Failover=PRIMARY and Failover=SECONDARY; Route 53 serves the secondary only when the primary's health check fails
4. Create a health check targeting your endpoint (HTTP/HTTPS/TCP, specific path, expected status code or response string match); associate the health check with the weighted or primary failover record by setting HealthCheckId on the record
5. For endpoints behind a load balancer or CloudFront, use Route 53 alias records (type A or AAAA, AliasTarget) instead of CNAME records — alias records are free, resolve at the DNS layer, and support zone apex (root domain) routing
6. Enable health check notifications via CloudWatch alarms on HealthCheckStatus metric to receive alerts when failover triggers