Amazon CloudFront | Edge Locations Flashcards
Can I point my zone apex (example.com versus www.example.com) at my Amazon CloudFront distribution?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Yes. By using Amazon Route 53, AWS’s authoritative DNS service, you can configure an ‘Alias’ record that lets you map the apex or root (example.com) of your DNS name to your Amazon CloudFront distribution. Amazon Route 53 will then respond to each request for an Alias record with the right IP address(es) for your CloudFront distribution. Route 53 doesn’t charge for queries to Alias records that are mapped to a CloudFront distribution. These queries are listed as “Intra-AWS-DNS-Queries” on the Amazon Route 53 usage report.
What is CloudFront Regional Edge Cache?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
A default CloudFront feature that brings more of your content close to your viewers, even when the content is not popular to stay at a particular edge location. This helps improve performance for your viewers while lowering the operational burden and cost of scaling your origin resources.
How does regional edge cache work?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Amazon CloudFront has added several regional edge cache locations globally, at close proximity to your viewers. These locations sit in between your origin webserver and the global edge locations that serve traffic directly to your viewers. As the popularity of your objects reduce, individual edge locations may evict those objects to make room for more popular content. Regional Edge Caches have larger cache width than any individual edge location, so objects remain in cache longer at these regional edge caches. This helps keep more of your content closer to your viewers, reducing the need for CloudFront to go back to your origin webserver and improving overall performance for viewers. For instance, our edge locations in Europe now go to the regional edge cache in Frankfurt to fetch an object before going back to your origin webserver. Regional Edge Cache locations are currently utilized only for requests that need to go back to a custom origin; i.e. requests to S3 origins will skip regional edge cache locations.
Is regional edge cache feature enabled by default?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Yes. You do not need to make any changes to your CloudFront distributions; this feature is enabled by default for all new and existing CloudFront distributions. There are no additional charges to use this feature.
Where are the edge network locations used by Amazon CloudFront located?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Amazon CloudFront uses a global network of edge locations and regional edge caches for content delivery. You can see a full list of Amazon CloudFront locations here.
Can I choose to serve content (or not serve content) to specified countries?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Yes, the Geo Restriction feature lets you specify a list of countries in which your users can access your content. Alternatively, you can specify the countries in which your users cannot access your content. In both cases, CloudFront responds to a request from a viewer in a restricted country with an HTTP status code 403 (Forbidden).
How accurate is your GeoIP database?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
The accuracy of the IP Address to country lookup database varies by region. Based on recent tests, our overall accuracy for the IP address to country mapping is 99.8%.
Can I serve a custom error message to my end users?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
Yes, you can create custom error messages (for example, an HTML file or a .jpg graphic) with your own branding and content for a variety of HTTP 4xx and 5xx error responses. Then you can configure Amazon CloudFront to return your custom error messages to the viewer when your origin returns one of the specified errors to CloudFront.
How long will Amazon CloudFront keep my files at the edge locations?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
By default, if no cache control header is set, each edge location checks for an updated version of your file whenever it receives a request more than 24 hours after the previous time it checked the origin for changes to that file. This is called the “expiration period.” You can set this expiration period as short as 0 seconds, or as long as you’d like, by setting the cache control headers on your files in your origin. Amazon CloudFront uses these cache control headers to determine how frequently it needs to check the origin for an updated version of that file. For expiration period set to 0 seconds, Amazon CloudFront will revalidate every request with the origin server. If your files don’t change very often, it is best practice to set a long expiration period and implement a versioning system to manage updates to your files.
How do I remove an item from Amazon CloudFront edge locations?
Edge Locations
Amazon CloudFront | Networking & Content Delivery
There are multiple options for removing a file from the edge locations. You can simply delete the file from your origin and as content in the edge locations reaches the expiration period defined in each object’s HTTP header, it will be removed. In the event that offensive or potentially harmful material needs to be removed before the specified expiration time, you can use the Invalidation API to remove the object from all Amazon CloudFront edge locations. You can see the charge for making invalidation requests here.
