#CDN

Question count - 0     Last updated    - V2 (01-Jun-2021)

What is a CDN?

Why use a CDN (Content Delivery Network‎)?

Name some advantages of using CDN for static JS files and assets?

What is a CDN origin server?

What are CDN edge servers?

Why and how to use Cache Busting?

What Is Cache Busting?

How does CDN caching work?

Explain why CDN (in)availability may be a problem for using WebSockets?

CDN - Content Delivery Network 

CDN refers to a geographically distributed group of servers which work together to provide fast delivery of Internet content

CDN is a service that caches your website and serves the website from geographically the nearest server which in turn increases the loading speed of the website.

A properly configured CDN may also help protect websites against some common malicious attacks, such as Distributed Denial of Service (DDOS) attacks.

It does help cache content at the network edge, which improves website performance

Edge Location - Location where content will be cached; separate to an AWS Region/AZ

Origin - Origin of all the files that the CDN will distribute. This can be an S3 Bucket, EC2 Instance, Elastic Load Balancer, or Route53, or not with AWS

Web Distribution - Typically used for websites

RTMP - Used for media streaming (adobe flash)

Edge Locations are not just read only, you can write to them, too

Objects are cached for life of TTL

Akamai vs Cloudflare Load balancing

Edge & Origin server

Data center

Internet exchange point

Proxy and Reverse proxy

Round-trip time

TTL- Time To Live

Cache Control - Static and Dynamic

GSLB

DDoS attack

Web Application Firewall (WAF)