Route 53 Flashcards
What is a DNS?
A domain naming system.
This turns human-understandable host names into IP addresses that the web browser uses to access servers.
What feature of DNS servers allows them to speed up repeat queries?
They cache IPs for a set period of time so they don’t have to go through the iterative process of finding them again
What is Route 53?
AWS managed DNS and domain registrar.
What is a useful feature of R53 for checking the availability of resources?
It supports health checks
What is a hosted zone?
A container for records that defines how to route traffic to a domain and its subdomains.
Comes in public and private flavours.
What is time to live for R53?
This is how long the client should cache a requested result after it is supplied by R53.
What happens if the time to live is set high or low for R53?
If high:
* less traffic on Route 53
* records could become outdated
If low:
* more traffic on Route 53 (can be expensive)
* records are less likely to become outdated
* easy to change the records
What is the difference between a CNAME and alias in AWS?
CNAME points a hostname to any other hostname. Only works for non-root domains.
Alias points a hostname to an AWS resource. Alias is free and works with both root and non-root domains.
What is a weighted routing policy?
Allows you to control the percentage of requests that go to each specific resource, 0 means no traffic goes to a resource and vice versa.
Why might one use weighted routing?
To test new application versions with just a small percentage of all users
What type of routing is used if you want to direct a user to a resource that will give them the quickest response time?
Latency routing
What routing policy would be used to direct users to the application based specifically on their location?
Geolocation
Why would one use geolocation routing?
To direct users to the relevant version of the app for them, e.g. German users to a german version
What is geoproximity routing?
Directs users to a resource based on their location and the location of the resource as well as a bias value that acts like gravity for the connections
What is multi-value routing?
IP based routing to route traffic to multiple resources. Can be used for resources inside and outside of the AWS cloud
