Expanding the Cloud: Amazon CloudFront

Today marks the launch of Amazon CloudFront, the new Amazon Web Service for content delivery. It integrates seamlessly with Amazon S3 to provide low-latency distribution of content with high data transfer speeds through a world-wide network of edge locations. It requires no upfront commitments and is a pay-as-you-go service in the same style as the other Amazon Web Services.

Amazon CloudFront has been designed to be fast; the service will cache copies of the content in edge locations close to the end-user's location, significantly lowering the access latency to the content. High sustainable data transfer rates can be achieved with the service especially when distributing larger objects.

Amazon CloudFront will be useful for many different application scenarios such as giving your customers low-latency access to popular objects and protecting your site from popularity surges; other popular examples are low-cost delivery of rich media and sustainable fast transfer rates for software distributions.

See also the posting on the AWS Developer weblog and at Rightscale.

Seamless integration

A content delivery service that would extend Amazon S3 has been something that is very high on the wish list of our customers. They were already successfully using Amazon S3 for some of their content distribution needs, but many wanted the choice to do so with even lower latency and with higher data transfer rates to any place in the world.

Customers really appreciate the scalability, reliability and cost-effectiveness of Amazon S3 and the fact that it integrates so easily with Amazon EC2. Amazon CloudFront builds further on that seamless integration by making it really simple to distribute Amazon S3 content world-wide. The combination of the two services is really powerful: Amazon S3 will give you durable storage of your data, and the network of edge locations on three continents used by the Amazon CloudFront will deliver the content to your customers with low latency from the most appropriate location.

The network of edge locations

To ensure low-latency delivery, Amazon CloudFront uses a network of edge locations world-wide:

• United States: Ashburn (VA), Dallas/Fort Worth, Los Angeles, Miami, Newark, Palo Alto, Seattle and St. Louis
• Europe: Amsterdam, Dublin, Frankfurt and London
• Asia: Hong Kong and Tokyo

These edge locations work together to direct customers' requests to the edge location that can provide the response with the lowest latency.

Simplicity

Because Amazon CloudFront follows the core principles of all Amazon Web Services it is a unique content delivery service. The simplicity in getting started has been described by many of our early customers as a very important feature.

Using Amazon CloudFront is dead simple:

1. Put your objects in an Amazon S3 bucket.
2. Call the CreateDistribution API with the name of the S3 bucket, which will return your distribution's domain name.
3. Use the new domain name in urls on your web or in your application. Whenever these urls are accessed CloudFront will determine the optimal edge location from where to serve your content.

Many of our private beta customers have reported that it only took them 10-15 minutes from the moment that they first signed up for the service to the moment that Amazon CloudFront was distributing their content.

The second Amazon Web Services principle that sets Amazon CloudFront apart is that no upfront commitments are necessary and you only pay for what you have used. There are no upfront fees or high volume requirements and no negotiations are necessary because we have published low prices from the start. This brings content delivery in the hands of all businesses, and you can exploit the benefits of Amazon's world-wide network of edge locations, regardless of whether you are a highly popular website, a small blog, a complex enterprise application or a developer doing some prototyping.

Tools such as S3Fox have support for Amazon CloudFront built-in such that if you want to avoid any programming you can immediately start exploiting world-wide, low-latency content delivery.

A core distributed systems component

It is not uncommon to think about a service for content delivery such as Amazon CloudFront only in the context of media distribution for web sites, but it actually plays a more fundamental role.

There are two main technology components to such a service; the first is intelligent request routing, which routes requests to the location that can best serve the user given a series of requirements and the status of the network. The second technology component is that of object caching, which is a fundamental building block in both operating systems and in distributed systems.

For example your operating system will have a file cache, where it will store popular, recently-accessed files in memory to provide much faster access and greater throughput. Without a file cache your whole computer would appear much slower as all work would happen at the speed of the disk instead of memory.

Caching is an essential technique that is used to make sure that components can operate at the fastest speed possible, to overcome the performance differences that exist in systems. For example CPU's have caches that are much faster than memory, memory works as caches for disks, local disks can function as caches for remote disks, etc.

In distributed systems caching is primarily used to provide fast access to popular objects that are located in remote storage servers. These systems of caching servers often cooperate to create massive aggregate world-wide capacity to provide low latency access. And by using globally decentralized cache servers for distribution, very high data transfer speed can be achieved.

Caching technology has long been the center piece of computer systems research and in Amazon CloudFront we use the type of highly advanced algorithms for reliability and scale that you have come to expect from our Amazon services.

Many of our customers will look to Amazon CloudFront for rock solid content distribution for websites, but its application is not limited to that. Developers can easily integrate the service into their desktop and server applications and benefit from the advanced routing and caching that Amazon CloudFront offers. For example enterprise style applications such as NASDAQ's Market Replay application are ideal candidates to integrate Amazon CloudFront to provide low latency access to popular market data while reducing the cost of data transfers.

Graphic by Renato Valdés Olmos of Postmachina