7.82 Weighted Routing Strategy

Weighted routing lets Route 53 split traffic across multiple resources according to ratios you define. Imagine three endpoints behind the same name: you can send 70% of requests to instance A, 20% to instance B and 10% to instance C. The weights you set are relative — Route 53 normalises them — so they do not have to add up to 100. Health checks can be attached to each weighted record, so unhealthy endpoints stop receiving traffic.

This strategy shines in two scenarios: canary releases (push 1% of users to a new version of an app and ramp up gradually) and traffic distribution across Regions. Combined with health checks, it gives you control over both performance and risk when rolling out changes.

Create the records in Route 53

  • Create a record, choose Weighted routing, type A, TTL 60 seconds.
  • First endpoint: IP of the Ireland instance, weight 70, record ID Ireland.
  • Second endpoint (Add another record): IP of the Frankfurt instance, weight 20, record ID Frankfurt.
  • Third endpoint: IP of the Asia instance, weight 10, record ID Asia.
  • Save — three records share the same name with distinct weights.

Once created, the three records appear with their respective weights. Route 53 will steer roughly 70% of incoming queries to Ireland, 20% to Frankfurt and 10% to Asia. Bring health checks into the mix and any endpoint marked unhealthy is dropped from the rotation. That is the weighted routing strategy in a nutshell — perfect for percentage-based experimentation and multi-Region traffic shaping.

Summary

The weighted routing strategy in AWS Route 53 allows you to distribute traffic between multiple resources by assigning weight values to each endpoint. By specifying proportional weights (such as 70, 20, and 10), you can control exactly how traffic is routed across different instances in various AWS regions. This strategy is particularly useful for testing new application versions with minimal traffic or gradually shifting load, and can be combined with health checks to ensure traffic only goes to healthy endpoints.

Key points

  • Weighted routing distributes incoming traffic proportionally based on assigned numeric weight values across multiple endpoints
  • Weight values are relative; Route 53 calculates the percentage distribution across all configured endpoints
  • Enables safe testing of new application versions by routing only a small percentage of traffic (e.g., 1%) while maintaining the majority on stable versions
  • Supports multi-region traffic distribution, routing traffic across instances in different geographic locations (Ireland, Frankfurt, Asia, etc.)
  • Each weighted routing record includes an endpoint IP address, weight value, and optional health check configuration
  • Records are created directly in Route 53 with unique names matching your routing strategy requirements

FAQ

How does Route 53 calculate traffic distribution with weighted routing?

Route 53 uses assigned weight values to determine traffic proportions. For example, with weights of 70, 20, and 10, the service distributes approximately 70% of traffic to the first endpoint, 20% to the second, and 10% to the third.

What are the main use cases for weighted routing strategy?

Common use cases include testing new application versions with minimal traffic exposure, performing gradual blue-green deployments between application versions, and distributing load across multiple geographic regions for improved performance and availability.

Can weighted routing be combined with health checks?

Yes, weighted routing records can be associated with Route 53 health checks to ensure traffic is only routed to healthy resources, preventing traffic from reaching failed or degraded endpoints.