ABSTRACT
Cloud computing, with the revolutionary promise of turning computing into a 5th utility, after water, electricity, gas, and telephony, has the potential to transform the face of Information Technology (IT), especially the aspects of service-rendition and service management. Though there are myriad ways of defining the phenomenon of Cloud Computing, we put forth the one coined by NIST (National Institute of Standards and Technology). According to them, Cloud Computing is defined as “A model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction” [84]. Loosely speaking, Cloud computing represents a new way to deploy computing technology to give users the ability to access, work on, share, and store information using the Internet [762]. The cloud itself is a network of data centers, each composed of many thousands of computers working together that can perform the functions of software on a personal or business computer by providing users access to powerful applications, platforms, and services delivered over the Internet. It is in essence a set of network enabled 4services that is capable of providing scalable, customized and inexpensive computing infrastructures on demand, which could be accessed in a simple and pervasive way by a wide range of geographically dispersed users. The Cloud also assures application based Quality-of-Service (QoS) guarantees to its users. Thus, Cloud Computing provides the users with large pools of resources in a transparent way along with a mechanism for managing the resources so that a user can access it ubiquitously and without incurring unnecessary performance overhead. The ideal way to describe Cloud Computing then would be to term it as “Everything as a Service” abbreviated as XaaS [100]. Below, we sum up the key features of Cloud Computing:
Agility – helps in rapid and inexpensive re-provisioning of resources.
Location Independence – resources can be accessed from anywhere and everywhere.
Multi-Tenancy – resources are shared amongst a large pool of users.
Reliability – dependable accessibility of resources and computation.
Scalability – dynamic provisioning of data helps in avoiding various bottleneck scenarios.
Maintenance – users (companies/organizations) have less work in terms of resource upgrades and management, which in the new paradigm will be handled by service providers of Cloud Computing.
