Defining types of clouds
The cloud hosts a multitude of capabilities in a variety of configurations. There are three basic types: public, private, and hybrid.
- Public cloud providers such as Amazon Web Services (aws.amazon.com) are open to anyone. “Anyone can provision resources,” said Steve Harriman, senior vice president of marketing, ScienceLogic. “Let’s say a project will take a number of engineers to do the design work and will need hardware on which to run the application. The project manager can open an account with AWS and request virtual machines, an inexpensive way to provision more computing power without procuring the physical servers. There is no investment in floor space or an environment to care for them. The project can provision the machines almost instantaneously and use them as long as they need them. Then, then can de-commission them, paying only for what they have used.”
- In a private cloud, the service provider has its own data centers that provision infrastructure to individual clients or companies. Resources are not shared and are not for public use. Industrial manufacturing leans toward private clouds because they offer more control. Public clouds typically are more acceptable for open activities, while private clouds are chosen when formulas and recipes that are confidential or proprietary are involved. “The private cloud configuration is more isolated and arguably more secure,” said Harriman. “Although it is not happening as yet, we anticipate that, in the future, a large-company IT organization may become a type of private cloud provider for its own company. Its end-user constituents would have a menu of services from which they could select and would be charged for in an internal bill-back.”
- As the name suggests, hybrid clouds are a combination of private and public types. Part of the infrastructure delivers resources from the public cloud while other resources reside in a private cloud. “Most cloud growth is taking place here because the technologies are becoming more heterogeneous,” noted Harriman. “Companies are more able to push internal and external resources more freely among cloud providers and can move those resources around with more agility.”
More about public and private clouds is available from ScienceLogic at www.sciencelogic.com. Or search public versus private clouds online for additional perspectives. Edited by Jeanine Katzel, Control Engineering contributing content specialist.
See related cloud-based automation articles associated with the December 2011 Control Engineering cover story.