CloudFront Flashcards
What does CloudFront provide?
CloudFront uses caching and an efficient global network to improve the delivery of content from its original location to the viewers of that content.
What is an origin in CloudFront?
The origin is the source location of your content. It can be an S3 origin or a custom origin (a web server with a publicly routable IPv4 address).
What is a distribution in CloudFront?
A distribution is the configuration unit of CloudFront.
What is an Edge Location in CloudFront?
An Edge Location is a local cache of your data.
What is a Regional Edge Cache in CloudFront?
A Regional Edge Cache is a larger version of an Edge Location that provides another layer of caching for content that is accessed less frequently, but still benefits from being cached closer to customers.
What rules must a CloudFront distribution domain name adhere to?
It must be unique and it must end in “cloudfront.net”.
Does CloudFront support SSL certificates?
Yes, CloudFront integrates with AWS Certificate Manager (ACM).
Does CloudFront support upload caching?
No, uploads are sent directly to the Origin. CloudFront supports read-only caching.
What are Behaviors in CloudFront?
Behaviors are part of a Distribution and define Origins, Origin Groups, TTL, Protocol Policies, and restricted access. Behaviors are configured with a path patterns (e.g., * or img/*). If a request matches a pattern (most specific wins), that Behavior is used.
When an expired cached object is requested at an Edge Location, what HTTP codes may be returned by the Origin when the Edge Location requests an update?
304 Not Modified (if the version in the cache is the small as the one in the Origin)
200 OK (along with a new version of the object)
What is a benefit of more frequent cache hits on Edge Locations in CloudFront?
Lower load on the Origin.
What is the default TTL for an object in a CloudFront cache?
24 hours.
What headers are used by the Origin to set the TTL value for an object?
Cache-Control max-age [seconds]
Cache-Control s-maxage [seconds]
Expires [Date & Time]
What can override the TTL value of an object in a CloudFront cache?
The minimum and maximum TTL values for the Behavior.
How do you manually invalidate specific objects in CloudFront?
You can use Cache Invalidation to invalidate specific paths (/images/cats.jpg or /images/* or /*) in a distribution. The invalidation is not instant (it takes time) and there is a cost.