Cloud Computing – Types of services
Services provided by cloud computing can be split into three major categories:
Infrastructure-as-a-Service(IaaS) like Amazon Web Services provides virtual servers with unique IP addresses and blocks of storage on demand. Customers benefit from an API from which they can control their servers. Because customers can pay for exactly the amount of service they use, like for electricity or water, this service is also called utility computing.
Platform-as-a-Service(PaaS) is a set of software and development tools hosted on the provider’s servers. Developers can create applications using the provider’s APIs. Google Apps is one of the most famous Platform-as-a-Service providers. Developers should take notice that there aren’t any interoperability standards (yet), so some providers may not allow you to take your application and put it on another platform.
Software-as-a-Service (SaaS) is the broadest market. In this case the provider allows the customer only to use its applications. The software interacts with the user through a user interface. These applications can be anything from web based email, to applications like Twitter or Last.fm.
Cloud Computing – Privacy, Security, and Standards Compliance
A major issue in cloud computing, especially with public clouds, is protection of user data. One concern is that cloud providers themselves may have access to customers’ unencrypted data – whether it’s on disk, in memory, or transmitted over the network. To limit this exposure, many sources recommend never giving providers access to unencrypted data or keys.
A second concern is that many public cloud providers are unable or unwilling to allow auditing of their physical or network security measures. This can preclude them, and thus their customers, from meeting standards such as the US government’s HIPAA or Sarbanes-Oxley, the European Union’s Data Protection Directive, or the credit card industry’s PCI DSS. The extent of some public clouds across multiple legal jurisdictions further complicates this issue. These concerns are considered key obstacles to broader adoption of cloud computing, making them areas of active research and debate among cloud computing practitioners and advocates.
Criticism of Cloud Computing System
Critics of cloud computing cite its seemingly broad and vague definition. Oracle CEO Larry Ellison observes that cloud computing has been defined as “everything that we currently do”. Forrester VP Frank Gillett expresses similar criticism. Many technologies that have been branded as “cloud computing” have existed for a long time before the “cloud” label came into existence. Examples include databases, load balanced on-demand web hosting services, network storage, real time online services, hosted services in general, etc.
Study: From Wikipedia, the free encyclopedia. The text is available under the Creative Commons.