Posted On: Jun 21, 2017

We are excited to announce that Amazon Route 53 now supports multivalue answers in response to DNS queries. While not a substitute for a load balancer, the ability to return multiple health-checkable IP addresses in response to DNS queries is a way to use DNS to improve availability and load balancing.

If you want to route traffic approximately randomly to multiple resources, such as web servers, you can create one multivalue answer record for each resource and, optionally, associate an Amazon Route 53 health check with each record. For example, suppose you manage an HTTP web service with a dozen web servers that each have their own IP address. No one web server could handle all of the traffic, but if you create a dozen multivalue answer records, Amazon Route 53 responds to DNS queries with up to eight healthy records in response to each DNS query. Amazon Route 53 gives different answers to different DNS resolvers. If a web server becomes unavailable after a resolver caches a response, client software can try another IP address in the response.

You can create multivalue answer records programmatically, using the Amazon Route 53 API, the AWS CLI, or the AWS SDKs. At launch, you can also create multivalue answer records using the traffic flow feature in the Amazon Route 53 console. To learn more, see the Amazon Route 53 documentation.