Amazon has made DNS available as a cloud implementation. Wait a minute, isn't DNS supposed to be a distributed service anyway?

Amazon has added DNS to its list of cloud services. Route 53, a clever but probably not a wise choice of names, is a distributed web service providing DNS lookup.

It can be used to route end users to multiple AWS services including Amazon EC2, an Amazon Elastic Load Balancer or an Amazon S3 bucket, and to infrastructure outside of AWS. It uses servers distributed across the globe and which server is used depends on where you are located for a fast response time.

Of course this sounds a lot like the standard DNS system, which has long been described as one of the best known and most used distributed databases ever.

So what is new?

Many web sites simply allow the hosting service to implement DNS. How this is done varies according to the hosting service but often it is a single machine or a small cluster at a single geographical location. This is usually included in the hosting cost. In addition acess to configure the DNS server is often restricted and if you move host you have to move DNS server.

The advantage of using Route 53 is that you have access to the virtual name servers that are implemented on Amazon's cloud infrastructure.This should make  things more reliable and if you move host you can still use the Route 53.

Of course, Amazon is charging for the use of its DNS facilities in addition to any fees you may also pay to use AWS. It is designed to work well with other AWS services. In particular you can point a DNS record at an AWS instance etc. Future facilities are planned to include mapping DNS to load balanced servers with geographic information being used to select the closest server for the client.

The system is also self service. You can sign up, log in and begin configuring your DNS records using the API. You are initially assigned four virtual name servers which you can work with via the ChangeResourceRecordSet API.  Of course, to make the changes have any effect you still have to contact the domain name registrar you originally registered the name with to update the IP address of your name servers  to the new Route 53 servers.

Charging is by number of domains managed, $1 per hosted zone and number of queries the service answers $0.50 per million queries (for first billion).

More infomation:

http://aws.amazon.com/route53/