Ref: https://learn.cantrill.io/courses/1820301/lectures/41301587
R53 Multivalue Answer Routing - Architecture
Diagram: https://github.com/acantril/aws-sa-associate-saac03/blob/main/1200-ROUTE53/00_LEARNINGAIDS/Route53MultiValueRouting-1.png
- 🔧 Supports multiple independent records with same host name
- e.g. Three
A records with name www, each mapping to a different IP address
- Each record can have an associated health check
- When host name is queried, up to 8 healthy records are returned to the client
- If more than 8 records are healthy, 8 are chosen at random and returned
- Client picks one of the records to connect to the resource
- ‼️ Unhealthy records are never returned!
- 💡 Mix of simple routing and failover routing, taking benefits of each
- 👍 Improves availability
- Active-active approach to DNS
- Requires architecture with multiple resources that can accept requests, where it's unimportant to know which resource serves which request
- ‼️ NOT a substitute for a load balancer!
- A load balancer handles the actual connection process from a NWing perspective
