Amazon Route 53 Health Checks and DNS Failover
Amazon Route 53 health checks monitor the health and performance of your web applications, web servers, and other resources. At regular intervals that you specify, Amazon Route 53 submits automated requests over the Internet to your application, server, or other resource to verify that it's reachable, available and functional.
You can configure a health check to make requests similar to those that your users make, such as requesting a web page from a specific URL. You can also view the current and recent status of health checks. If you want to receive a notification when an application or a resource becomes unavailable, you can configure an Amazon CloudWatch alarm for each health check. For information about creating health checks, see Creating, Updating, and Deleting Health Checks. For information about viewing health check status and receiving notifications, see Monitoring Health Check Status and Getting Notifications.
If you have multiple resources that perform the same function, for example, web servers or email servers, and you want Amazon Route 53 to route traffic only to the resources that are healthy, you can configure DNS failover by associating health checks with your resource record sets. If a health check determines that the underlying resource is unhealthy, Amazon Route 53 routes traffic away from the associated resource record set. For more information, see Configuring DNS Failover.