CloundFront is Amazon’s CDN. It’s a system of distributed servers that deliver content to a user based on the geographic location of the user, content origin, and the delivery server.
- Edge Location => Location where content is cached.
- Origin => Origin of all files the CDN will distribute. Can be S3 bucket, EC2 Instance, ELB, or Route53, but does not have to be an AWS service.
- Distribution => Name given to the collection of edge locations
- Web Disbribution => Website distribution
- RTMP Distribution => Media (Adobe Flash) distribution
How it works
User-A in California wants a video file that’s stored in the UK. User-A requests the video from the edge location closest to them. That edge location retrieves and caches the video file from the UK. User-B, also in California, requests the same video file. Instead of retrieving the file from the UK, User-B is able to get the file from the edge location.
- Edge locations are not just READ only.
- Objects are cached for the life of the TTL
- You can clear cached objects early for $$
- You can have multiple origins in the same distribution
- TTLs are in seconds