Cloud-computing platforms such as Amazon’s Elastic Compute Cloud (EC2), Microsoft’s Azure Services Platform, and Google App Engine have given many businesses flexible access to computing resources, ushering in an era in which, among other things, startups can operate with much lower infrastructure costs. Instead of having to buy or rent hardware, users can pay for only the processing power that they actually use and are free to use more or less as their needs change.
However, relying on cloud computing comes with drawbacks, including privacy, security, and reliability concerns. So there is now growing interest in open-source cloud-computing tools, for which the source code is freely available. These tools could let companies build and customize their own computing clouds to work alongside more powerful commercial solutions.
One open-source software-infrastructure project, called Eucalyptus, imitates the experience of using EC2 but lets users run programs on their own resources and provides a detailed view of what would otherwise be the black box of cloud-computing services.
Another open-source cloud-computing project is the University of Chicago’s Globus Nimbus, which is widely recognized as having pioneered the field. And a European cloud-computing initiative coordinated by IBM, called RESERVOIR, features several open-source components, including OpenNebula, a tool for managing the virtual machines within a cloud. Even some companies, such as Enomaly and 10gen, are developing open-source cloud-computing tools.
Rich Wolski, a professor in the computer-science department at the University of California, Santa Barbara, who directs the Eucalyptus project, says that his focus is on developing a platform that is easy to use, maintain, and modify. “We actually started from first principles to build something that looks like a cloud,” he says. “As a result, we believe that our thing is more malleable. We can modify it, we can see inside it, we can install it and maintain it in a cloud environment in a more natural way.”
Reuven Cohen, founder and chief technologist of Enomaly, explains that an open-source cloud provides useful flexibility for academics and large companies. For example, he says, a company might want to run most of its computing in a commercial cloud such as that provided by Amazon but use the same software to process sensitive data on its own machines, for added security. Alternatively, a user might want to run software on his or her own resources most of the time, but have the option to expand to a commercial service in times of high demand. In both cases, an open-source cloud-computing interface can offer that flexibility, serving as a complement to the commercial service rather than a replacement.