In Route 53 you have different routing policies for how Route 53 responds to DNS queries the first three are rather simple so I’ll go over them in the same post. Simple routing is actually the simplest and most straight forward. If you have one value listed for example www.example.com maps to an A record of 11.22.33.44 or it can map to multiple IPs and one is chosen at random when you connect. Simple routing policy cannot be associated with health checks. Weighted routing policy allows a little more control than simple routing policy, you can assign a weight to each record and that affects the percentage of traffic that gets directed to it, the formula is record weight / total record weight = percentage of traffic. So if you have a weight of 10 and combined weight of 100 then 10 / 100 = 10% of requests will receive that DNS response. The weights don’t have to add up to 100 they can be relative to each other. The weighted policy does support health checks. Finally we have the Latency-based Routing Policy. This policy does support health checks. It routes to the resource with the lowest latency, fairly straight forward that’s all there is to it, great option if low latency is paramount to your application.