Route 53 Routing Policies (1/2)
Route 53 includes routing policies that determine how it responds to client DNS queries. These policies enable you to configure different ways to route traffic based on conditions or events. There are 8 routing policies that you need to know for the Solutions Architect exam, and this post only covers the first four.
Simple routing: directs traffic to a single resource, like a web browser. If there are multiple IP addresses associated with that resource, Route 53 will return all of the IP addresses, but the client will pick one at random.
Weighted routing: different weights are assigned to individual resources, and Route 53 splits traffic based on the assigned proportions. For example, one EC2 instance gets 70% of the traffic, another 20% and the last one 10%.
Latency-based routing: this is similar to a geographic policy, but it's actually based on how Route 53 calculates latency between users and AWS resources like an Elastic Load Balancer. Usually, clients will be routed to networks with the lowest latency.
Failover routing: health checks must be created, and if they fail then Route 53 will stop sending traffic to the secondary/backup instances if the primary fails those checks.
