Optimizing Traffic Distribution: A Closer Look at Weighted Routing in Route 53

What is Weighted Routing

Weighted routing allows the association of multiple resources with a single domain name (e.g., example.com) or subdomain (e.g., acme.example.com) while providing control over the distribution of traffic among these resources. This capability serves various purposes, such as load balancing and facilitating software version testing.

To configure weighted routing, you create records that share the same name and type for each of your resources. You then assign a relative weight to each record, indicating the proportion of traffic you intend to direct to that particular resource. Amazon Route 53, in turn, routes traffic to a resource based on the weight assigned to the record relative to the cumulative weight of all records within the group.

As an illustration, suppose you wish to direct a small fraction of your traffic to one resource while directing the majority to another. In this case, you could set weights of 1 and 255. The resource assigned a weight of 1 would receive 1/256th of the traffic (1 divided by the sum of 1 and 255), while the other resource would receive 255/256ths (255 divided by the sum of 1 and 255). By adjusting the weights, you can gradually alter the traffic distribution. If you no longer wish to route traffic to a specific resource, you have the option to set the weight for that record to 0.