What is Amazon CloudFront?

According to the Amazon Web Services (AWS) website, Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs with low latency and high transfer speeds to customers (globally) within a developer-friendly environment.

How does CloudFront work?

Cloudfront is used to deliver static and dynamic content and applications to users all over the globe. It does so using a worldwide network of data centers that Amazon refers to as edge locations. CloudFront is integrated with AWS at physical locations that are directly connected to the AWS global infrastructure and other AWS services.

Let’s understand it through the help of a simple example. Consider a bucket consisting of cute cat videos. Users all over the world want to access them. To cater to these requirements, we put a CloudFront distribution in front of an S3 bucket.

Now, suppose a user in a remote location wants to access a particular cat video and sends a GET request to the S3 bucket. There are 3 important steps that would take place.

Step 1: Look for the video in the edge location

As the user accesses the videos through the CloudFront distribution, CloudFront looks for the video in the regional edge cache. If the video is trending and has been accessed by multiple users recently, it would be available in the cache, also known as a cache hit. The video will be returned to the user from the cache.

Step 2: Look for the video in the regional edge cache

If the video is not available in the cache of the edge location, it’s a cache miss. CloudFront would then forward the request to the regional edge cache between the edge location and the S3 bucket. If the video is available on the regional edge cache, it is returned to the user.

Step 3: Return the video from the origin server

If the video is not available at the regional edge cache as well, the request is forwarded to the origin server, in our case, the S3 bucket.

CloudFront works seamlessly with other services that act as origins for your applications (e.g., AWS Shield for DDoS mitigation, Amazon S3, Elastic Load Balancing, or Amazon EC2).

Use cases of CloudFront

Speed up the loading of static assets like HTML, CSS, JavaScript, and images for better user experiences.

• Deliver high-quality, low-latency video content to viewers globally, including adaptive bitrate streaming.

• Secure sensitive data by encrypting specific fields during transmission and processing with field-level encryption.

• Use Lambda@Edge or CloudFront functions to tailor requests and responses, which enables personalized content delivery.

• Restrict access to private content by customizing authentication and access controls at the edge.

Amazon CloudFront pricing

Amazon CloudFront pricing is determined based on data transfer, request volumes, and the features you use.

• Data transfer out charges: CloudFront pricing includes costs for data transferred from edge locations to end users. Rates vary by region and decrease with higher usage volumes.

• Request-based fees: Charges apply for HTTP and HTTPS requests, with rates depending on the protocol and geographic region.

• Free data transfer from AWS origins: Transfers from AWS services like Amazon S3, Elastic Load Balancing, or Amazon API Gateway to CloudFront are free.

• Billing for viewer traffic: When using AWS origins, costs are incurred only for data transferred from CloudFront to the end viewer.

Benefits of CloudFront

According to Amazon, CloudFront has the following key benefits:

• Fast and global: The Amazon CloudFront content delivery network (CDN) is massively scaled and globally distributed—it has 216 points of presence (PoPs).

• Security: CloudFront is a highly secure CDN that provides both network and application-level protection. All traffic and applications benefit through a variety of built-in protections, like AWS Shield Standard, at no additional cost.

• Highly programmable: Amazon CloudFront features can be customized for your specific application requirements.

• Deep integration with AWS: Amazon CloudFront is integrated with AWS services like Amazon S3, Amazon EC2, Elastic Load Balancing, Amazon Route 53, and AWS Elemental Media Services.