Explanation: You can set up a variety of failover configurations using Amazon Route 53 alias: weighted, latency,geolocation routing, and failover resource record sets. Active-active failover: Use this failover configuration when you want all of your resources to beavailable the majority of the time. When a resource becomes unavailable, Amazon Route 53 candetect that it's unhealthy and stop including it when responding to queries. Active-passive failover: Use this failover configuration when you want a primary group of resources to be available themajority of the time and you want a secondary group of resources to be on standby in case all of theprimary resources become unavailable. When responding to queries, Amazon Route 53 includes only the healthy primary resources. If all of the primary resources are unhealthy, Amazon Route 53 beginsto include only the healthy secondary resources in response to DNS queries. Active-active-passiveand other mixed configurations: You can combine alias and non-alias resource record sets to producea variety of Amazon Route 53 behaviors. Reference: http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover.html