File Virtualization

Amazon’s Elastic Cloud (EC2) remains one of the leading solutions for web-based applications. In fact, when combined with their S3 (Simple Storage Service), you can host and deliver data for a fraction of the cost of traditional delivery. The primary advantage of EC2 is scale: you can shift  to a software as a service model, and provide data-intensive services without incurring expensive data transfer costs using Amazon’s platform; many users are (pleasantly) surprised at the relatively low cost of data transfer through Amazon.

From a technical perspective, the system utilizes Xen virtualization across a number of virtual private servers. Simply, Xen is a virtual machine software released under General Public License (from Cambridge University) which allows multiple virtual guests on a single hardware machine. In practice, this means (in theory) you can have the power of an entire data center on demand and will only pay for the data transfer you utilize; thus, ensuring that you have little or no fixed costs traditionally associated with data centers. The rates for EC2 vary, based on your use, but start as low as 20c per GB of transfer, along with a baseline instance charge for simultaneous users. For companies that offer streaming media or real-time data transfer, EC2 is a highly cost effective route.

A number of compatible solutions allow you easy to run Rails on the Cloud, and there are companies which specialize in helping you setup your software through Amazon. The key question to ask is: will EC2 be a more cost effective route for my web app? The simple answer depends on your bandwidth use, as well as how easily your software can be ported onto the service; a cloud consulting firm should be able to give you an estimate of the startup and marginal costs to help you make an informed decision.