What Is Cloud Computing

Posted: September 14th, 2011 | Author: jrliem | Filed under: cloud basic | Tags: what is cloud computing

Until the time I’m writing this post, the industry definition of cloud computing that widely accepted does not exist. You will find few definitions for this buzz term; vary from short to long description. In this post I am going to share with you the few definitions I found and cloud computing modeling services. I hope it can help you in figuring out what is cloud computing.

What is cloud computing — the definitions

1. Cloud computing is a type of computing which have to serve to the computing demands as follow :

Dynamism which enables you to fulfill the demands of IT easier and faster.
Abstraction which which enables you to concentrate on your main competency & shouldn’t be worried about OS, security, software platform, patches, updates and so forth. Leave all these jobs to your provider.
Resource Sharing provides the flexibility to share applications as well as other network resources (hardware etc). This will lead to need based flexible architecture where the resources will expand or contract with little configuration changes.

2. Cloud computing is the 5th Generation Computing after Mainframe, Personal Computer, Client-Server Computing, and the web.

3. In its broadest application, the definition of cloud computing refers to the scalable IT resources delivery over the Internet, as contrast to hosting and operating all those resources locally, like on network of an university or college. Those resources range from service and applications, and also the infrastructure on which they use.

4. According to National Institute of Standards and Technology’s (NIST): Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., servers, networks, services , storage, and applications) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

5. Cloud computing is hardware hosting within an external data center (sometimes named infrastructure as a service or IaaS), application hosting (often named software or application as a service), platform services (often named middleware as a service) and utility computing (which bundles computing resources to allow them to be used as a tool in an always-on, metered, and elastically scalable way.

6. Fundamentally, cloud is about developing and performing dynamic shared computing circumstances that can service numerous users and applications on this common infrastructure which can be accessed by self-serve technologies.

What is cloud computing — the modeling service

Cloud computing - Wiki

The various types of cloud computing services are included into three distinct models :

1. Cloud computing – Infrastructure as a Service (IaaS) offers computer hardware (networking, servers, data center space, storage, and technology) as a service. This could also include the operating systems and also delivery virtualization technology for managing the resources.

The IaaS customer does not need to buy or install computer resources instead rents them from provider for their own data center. The customer usually pays the service on a usage basis.

This service may contain dynamic scaling to enable customer winds up requiring additional resources than estimated, he can get them instantly (likely up to a given limit).

Dynamic scaling as utilized by infrastructure implies that the infrastructure can be scaled up or down automatically, according to the application requirements.

At the moment, Amazon’s Elastic Compute Cloud (Amazon EC2) is the most high-profile IaaS operation. It offers a Web interface that enables customers to access virtual machines. EC2 provides scalability under the control of user with the resources is paid by the hour.

2. Cloud computing - Platform as a Service (PaaS). The PaaS provider delivers more than infrastructure. It delivers what you might call a solution stack — an integrated set of software that provides everything a developer needs to build an application — for both software development and runtime.

PaaS can be viewed as an evolution of Web hosting. In recent years, Webhosting companies have provided fairly complete software stacks for developing Web sites. PaaS takes this idea a step farther by providing lifecycle management — capabilities to manage all software development stages from planning and design, to building and deployment, to testing and maintenance.

The primary benefit of PaaS is having software development and deployment capability based entirely in the cloud — that’s why, no effort for managing or maintaining that are needed for the infrastructure. Each software development aspect, from the design phase onward (including source-code management, testing, and deployment) lives in the cloud.

The major drawback of Platform as a Service is that it may lock you in to the use of a particular development environment and stack of software components. Platform as a Service offerings usually have some proprietary elements (perhaps the development tools or even component libraries). Consequently, you may be wedded to the vendor’s platform and unable to move your applications elsewhere without rewriting them to some degree.

If you suddenly become dissatisfied with your PaaS provider, you may face very high expenses when you suddenly need to rewrite the applications to satisfy the requirements of another PaaS vendor.

The fear of vendor lock-in has led to a new variety of Platform as a Service emerging: Open Platform as a Service. This would offer the same approach as Platform as a Service, except that there is no constraint on choice of development software. It avoids the possibility of lock-in.

Some examples of Platform as a Service include the Google App Engine, AppJet, Etelos, Qrimp, and Force.com.

3. Cloud computing – Software as a Service (SaaS). SaaS has its roots in an early kind of hosting operation carried out by Application Service Providers (ASPs). The ASP business grew up soon after the Internet began to mushroom, with some companies offering to securely, privately host applications. Hosting of supply chain applications and customer relationship management (CRM) applications was particularly prominent, although some ASPs simply specialized in running email. Prior to the advent of this type of service, companies often spent huge amounts of money implementing and customizing these applications to satisfy internal business requirements. Many of these products weren’t only difficult to implement but hard to learn and use. However, the most successful vendors were those who recognized that an application delivered as a service with a monthly fee based on the number of users had to be easy to use and easy to stay with.

The software price is usually on a per-use base and no in advance costs involved from the service provider. (Of course, in fact your organization could perhaps have some upfront works to do in order to get your data uploaded into the Software as a Service application database and also you may need to manage ongoing data integration between your internal data stores and cloud.) Businesses will have the instance benefit of reducing capital expenses. Moreover, a business gets the flexibility to try new application on a rental base and then can continue to use.