Cloud Computing

Cloud Computing

Term cloud computing was introduced by Eric Schmidt, current executive chairman of Google. When he worked as a chief technology officer at Sun Microsystems, Schmidt already had come to a conclusion that network and computer are closely related. Later this concept spread around as official Sun Microsystems motto: “The Network Is The Computer”. That phrase is an utterly laconic version of the idea pronounced by Schmidt in 1993: “As soon as the network becomes as responsive as CPU, the computer as such will no longer exist, it will spread over the network.”

As of today, many interpretations of "cloud computing" term can be found. Each major analytic agency suggests their proprietary definitions, which often are ambiguous and complicated. Due to this, we think it will be the right thing to take the definition given by the National Institute of Standards and Technology as a reference instead.

A system is called a cloud system when it has the following features:

  • Dynamic allocation of resources for the purpose of meeting users’ requirements related to computing resources and services
  • Emulation of a “limitless” pool of virtual resources available on the first request
  • Elasticity, which is namely an ability to dynamically perform horizontal scaling, both to the side of increasing computing power and to the side of decreasing it
  • Wide range of ways to deliver computing resources and services to the end user
  • Measurable quality of services provided. Maintaining consistent quality of service is achieved by automatic reallocation of internal resources.

A wide range of IT systems fall under this definition. Thus there is a problem of identifying an infrastructure or a technology as a cloud system.

The suggested solution lies in classification of basic services within the scope of this technology:

  • SaaS — software as a service. It is a commonly used method of providing access to the software, which offers required functionality. At the same time the user has no means of controlling the provider’s internal systems. One exception can be made for software used for controlling access to the service
  • PaaS — platform as a service. Cloud provider grants access to an application development platform within the cloud environment. The user has no means of controlling the platform or cloud infrastructure, but he can develop, test and execute own applications on the provided platform
  • IaaS — IT infrastructure as a service. Cloud provider hands over a set of systems to the user. This set includes such systems as virtual server, data storage or network hardware. In this service model the user can install own software as well as control operating system, network connections, and data storage.

If we combine features of a cloud system and methods of service packaging, a question arises regarding the model of cloud ownership. Usually it is divided to the following classes:

  • Public Cloud – this model implies that the infrastructure can be used by everyone. For example, such system us created by one of global providers, whose services are sold online and any user has an opportunity to buy the needed service
  • Private Cloud – this model implies that the system is created and operated by a single organization and no one else
  • Hybrid Cloud – mixed cloud ownership model. Such cloud implies that one cloud system (either private or public) is integrated with another cloud system (private or public).

Today tools and platforms for implementing cloud computing are offered by such companies as: Amazon (Virtual Private Cloud), BMC Software (Cloud Lifecycle Management), CA (3Tera AppLogic), Cisco/EMC/VMware (Vblock), Citrix Systems (Citrix Open Cloud), Cloud.com (CloudStack 2.0), Dell (Virtual Integrated System), Enomaly (Elastic Computing Platform), Eucalyptus Systems (Eucalyptus 2.0), HP (BladeSystem Matrix), IBM (CloudBurst), NewScale (NewScale 9), Novell (Cloud Manager), Oracle (Exalogic Elastic Cloud), Platform Computing (Platform ISF), Tibco Software (Tibco Silver), VMware (vCloud, vSphere and vCenter). Examples of complex (integrated) solutions are: vBlock by EMC, Cisco and VMware, FlexPod by Cisco, NetApp and VMware.