Section 8: DNS, caching & performance Flashcards
What is Amazon Route53
Route 53 is DNS server
What is AWS CloudFront
CloudFront is a CDN (Content Delivery Network) which caches data in different locations around the work, closest to where the user is. This improves performance by reducing latency (delay). The idea being to deliver static assets like images/videos/files closer to the user.
What is AWS Global Accelerator?
AWS Global Accelerator is a service that uses edge locations to look for the optimal pathway from your users to your applications. This means it will help reduce latency when possible by serving from the nearest location.
AWS Global Accelerator vs CloudFront - https://tutorialsdojo.com/aws-global-accelerator-vs-amazon-cloudfront/
What does a DNS do?
The Domain Name Server (DNS) resolves the domain name (e.g. mycompany.com) to the IP address on the web server.
E.g. mywebsite.com (domain name) = 64.190.63.111 (IP address)
https://www.nslookup.io/website-to-ip-lookup/
Route 53 routing policies
Route 53 routing policies include things such:
* geolocation (location you’re in)
* weighted (assign weight to resources to determine which to route to)
* IP based (use the IP address to determine route decisions)
* And a few other too…
What is a Route 53 hosted zone?
Route 53 hosted zone is a file that contains DNS records. This file represents a collection of records that can be managed together, belonging to a single parent domain name. All resource record sets within a hosted zone must have the hosted zone’s domain name as a suffix
What does Route 53 Resover provide?
Amazon Route 53 Resolver provides a robust toolset for DNS query resolution across AWS, the internet, and on-premises networks with secure control over your Amazon Virtual Private Cloud (VPC) DNS
https://aws.amazon.com/route53/resolver/
What is Lambda@Edge
Lambda@Edge runs Node.js and Python Lambda functions that executes closer to the user
User request is known as Viewer request
Server response is known as Origin response
https://aws.amazon.com/lambda/edge/
Route 53 offerings
Route 53 offer the following:
* Domain name registry
* DNS resolution
* Health checking of resources
Route 53 is also located alongside all edge locations
Route 53 hosted zones - public vs private
Route 53 hosted zones
- public hosted zone = determines how traffic is routed on the internet
- private hosted zone for VPC = determines how traffic is routes within VPC
CNAME vs Alias
Alias records can be used to map a hostname (top level) to any AWS resource that has a publicly resolvable DNS name, whereas CNAME records can only map to a domain or subdomain. Alias records can be updated automatically if the IP address of the AWS resource changes, whereas CNAME records would need to be updated manually
https://blog.gowthamparamasivam.com/cname-vs-aws-route-53-alias
An Architect is designing a web application that has points of presence in several regions around the world. The Architect would like to provide automatic routing to the nearest region, with failover possible to other regions. Customers should receive 2 IP addresses for whitelisting. How can this be achieved?
AWS Global Accelerator
AWS Global Accelerator provides static IP addresses that act as a fixed entry point to application endpoints in a single or multiple AWS Regions. It uses 2 static anycast IP addresses.
Which are valid origins for CloudFront
valid CloudFront origins include:
* S3 buckets
* EC2 instance
* Elastic Load Balancer
Note: Lambda functions are NOT valid origins for CloudFront
Cheat sheets for this section
Cheat sheets:
* https://digitalcloud.training/amazon-route-53/
* https://digitalcloud.training/amazon-cloudfront/
* https://digitalcloud.training/aws-global-accelerator/
