CLOUD COMPUTING

What is Cloud Computing?

Cloud Computing is the use of hardware and software to deliver a service over a network (typically the Internet). With cloud computing, users can access files and use applications from any device that can access the Internet. An example of a Cloud Computing provider is Google's Gmail.

Cloud computing offers platform independency, as the software is not required to be installed locally on the PC. Hence, the Cloud Computing is making our business applications mobile and collaborative.

Basic Concepts

There are certain services and models working behind the scene making the cloud computing feasible and accessible to end users. Following are the working models for cloud computing:

1. Deployment Models

    2.Service Models

• Deployment Models

Deployment models define the type of access to the cloud, i.e., how the cloud is located? Cloud can have any of the four types of access: Public, Private, Hybrid, and Community.

PUBLIC CLOUD

The public cloud allows systems and services to be easily accessible to the general public. Public cloud may be less secure because of its openness.

PRIVATE CLOUD

The private cloud allows systems and services to be accessible within an organization. It is more secured because of its private nature.

COMMUNITY CLOUD

The community cloud allows systems and services to be accessible by a group of organizations.

HYBRID CLOUD

The hybrid cloud is a mixture of public and private cloud, in which the critical activities are performed using private cloud while the non-critical activities are performed using public cloud.

• Service Models

Cloud computing is based on service models. These are categorized into three basic service models which are -

• Infrastructure-as–a-Service (IaaS)
• Platform-as-a-Service (PaaS)
• Software-as-a-Service (SaaS)

Anything-as-a-Service (XaaS) is yet another service model, which includes Network-as-a-Service, Business-as-a-Service, Identity-as-a-Service, Database-as-a-Service or Strategy-as-a-Service.

The Infrastructure-as-a-Service (IaaS) is the most basic level of service. Each of the service models inherit the security and management mechanism from the underlying model, as shown in the following diagram

INFRASTRUCTURE-AS-A-SERVICE (IAAS)

IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage, etc.

PLATFORM-AS-A-SERVICE (PAAS)

PaaS provides the runtime environment for applications, development and deployment tools, etc.

SOFTWARE-AS-A-SERVICE (SAAS)

SaaS model allows to use software applications as a service to end-users.

History of Cloud Computing

The concept of Cloud Computing came into existence in the year 1950 with implementation of mainframe computers, accessible via thin/static clients.Since then, cloud computing has been evolved from static clients to dynamic ones and from software to services. The following diagram explains the evolution of cloud computing

Benefits

Cloud Computing has numerous advantages. Some of them are listed below -

·        One can access applications as utilities, over the Internet.

·        One can manipulate and configure the applications online at any time.

·        It does not require to install a software to access or manipulate cloud application.

·        Cloud Computing offers online development and deployment tools, programming runtime environment through PaaS model.

·        Cloud resources are available over the network in a manner that provide platform independent access to any type of clients.

·        Cloud Computing offers on-demand self-service. The resources can be used without interaction with cloud service provider.

·        Cloud Computing is highly cost effective because it operates at high efficiency with optimum utilization. It just requires an Internet connection

·        Cloud Computing offers load balancing that makes it more reliable.