Amazon Route 53 | DNS Traffic Flow Flashcards
Does Amazon Route 53 support multiple values in response to DNS queries?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
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 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. Amazon Route 53 supports up to eight healthy records in response to each DNS query.
What is Amazon Route 53 Traffic Flow?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
Amazon Route 53 Traffic Flow is an easy-to-use and cost-effective global traffic management service. With Amazon Route 53 Traffic Flow, you can improve the performance and availability of your application for your end users by running multiple endpoints around the world, using Amazon Route 53 Traffic Flow to connect your users to the best endpoint based on latency, geography, and endpoint health. Amazon Route 53 Traffic Flow makes it easy for developers to create policies that route traffic based on the constraints they care most about, including latency, endpoint health, load, geoproximity and geography. Customers can customize these templates or build policies from scratch using a simple visual policy builder in the AWS Management Console.
What is the difference between a traffic policy and a policy record?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
A traffic policy is the set of rules that you define to route end users’ requests to one of your application’s endpoints. You can create a traffic policy using the visual policy builder in the Amazon Route 53 Traffic Flow section of the Amazon Route 53 console. You can also create traffic policies as JSON-formatted text files and upload these policies using the Route 53 API, the AWS CLI, or the various AWS SDKs.
By itself, a traffic policy doesn’t affect how end users are routed to your application because it isn’t yet associated with your application’s DNS name (such as www.example.com). To start using Amazon Route 53 Traffic Flow to route traffic to your application using the traffic policy you’ve created, you create a policy record which associates the traffic policy with the appropriate DNS name within an Amazon Route 53 hosted zone that you own. For example, if you want to use a traffic policy that you’ve named my-first-traffic-policy to manage traffic for your application at www.example.com, you will create a policy record for www.example.com within your hosted zone example.com and choose my-first-traffic-policy as the traffic policy.
Policy records are visible in both the Amazon Route 53 Traffic Flow and Amazon Route 53 Hosted Zone sections of the Amazon Route 53 console.
Can I use the same policy to manage routing for more than one DNS name?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
Yes. You can reuse a policy to manage more than one DNS name in one of two ways. First, you can create additional policy records using the policy. Note that there is an additional charge for using this method, because you are billed for each policy record that you create.
The second method is to create one policy record using the policy, and then for each additional DNS name that you want to manage using the policy, you create a standard CNAME record pointing at the DNS name of the policy record that you created. For example, if you create a policy record for example.com, you can then create DNS records for www.example.com, blog.example.com, and www.example.net with a CNAME value of example.com for each record. Note that this method is not possible for records at the zone apex, such as example.net, example.org, or example.co.uk (without www or another subdomain in front of the domain name). For records at the zone apex, you must create a policy record using your traffic policy.
Can I create an Alias record pointing to a DNS name that is managed by a traffic policy?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
No, it is not possible to create an Alias record pointing to a DNS name that is being managed by a traffic policy.
Is there a charge for traffic policies that don’t have a policy record?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
No. We only charge for policy records; there is no charge for creating the traffic policy itself.
How am I billed for using Amazon Route 53 Traffic Flow?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
You are billed per policy record. A policy record represents the application of a Traffic Flow policy to a specific DNS name (such as www.example.com) in order to use the traffic policy to manage how requests for that DNS name are answered. Billing is monthly and is prorated for partial months. There is no charge for traffic policies that are not associated with a DNS name via a policy record. For details on pricing, see the Amazon Route 53 pricing page.
What are the advanced query types supported in Amazon Route 53 Traffic Flow?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
Traffic Flow supports all Amazon Route 53 DNS Routing policies including latency, endpoint health, multivalue answers, weighted round robin, and geo . In addition to these, Traffic Flow also supports geoproximity based routing with traffic biasing.
How does a traffic policy using geoproximity rule route DNS traffic?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
When you create a traffic flow policy, you can specify either an AWS region (if you’re using AWS resources) or the latitude and longitude for each endpoint. For example, suppose you have EC2 instances in the AWS US East (Ohio) region and in the US West (Oregon) region. When an user in Seattle visits your website, geoproximity routing will route the DNS query to the EC2 instances in the US West (Oregon) region because it’s closer geographically. For more information please see the documentation on geoproximity routing.
How does geoproximity bias of an endpoint affect dns traffic routing to other endpoints?
DNS Traffic Flow
Amazon Route 53 | Networking & Content Delivery
Changing geoproximity bias value on an endpoint either increases or decreases the value of the calculated distance relative to the other endpoints. However, the bias does not accurately predict the load factor but rather changes the sphere of influence. The amount of traffic shifting depends on how much queries are generated within the geographical sphere of influence of an endpoint. For more information please refer our documentation.
