Original URL: http://www.theregister.co.uk/2013/05/31/amazon_cloud_failover_elb/

AWS peers into soul of Load Balancers for DNS failover

Route 53 DNS service gets much-requested feature

By Jack Clark

Posted in Cloud, 31st May 2013 19:34 GMT

Amazon Web Services now lets users apply automated DNS failover policies to data fronted by load balancers rather than just IPs.

As El Reg predicted, Amazon has now added Elastic Load Balancer (ELB) failover to Route 53 just three months after launching a new auto-redirect feature. This means Amazon's "dead man switch" failover technology is now usable for a large subset of the AWS cloud.

"With DNS Failover, Amazon Route 53 can help detect an outage of your website and redirect your end users to alternate locations where your application is operating properly," Amazon wrote on Thursday when it announced the service. "When you enable this feature, Route 53 uses health checks – regularly making Internet requests to your application's endpoints from multiple locations around the world – to determine whether each endpoint of your application is up or down."

The technology evaluates the health of the load balancer, and the status of the apps running on the EC2 infrastructure behind it. If ELBs or EC2 instances break, Route 53 can route traffic away from the affected resources.

This technology combines with Amazon's previous auto-migration enancement to Route 53 to cut the work needed by cloud admins to implement a downtime policy for an AWS-hosted asset.

As ELB's typically front sophisticated applications, by making auto-failover possible for these assets Amazon has further eased the setup of downtime policies for sites that straddle multiple AWS data centers around the world.

Along with helping developers cheaply architect apps and sites that won't go down as severely when underlying EC2 infrastructure fails, the tech should help Amazon avoid headlines about how when it goes down, much of the consumer internet disappears with it. ®