Cloud Computing is a comprehensive umbrella term. Some analysts and vendors perceive it as just an updated version of utility-computing with virtual servers available over the Internet. Other definitions pose the argument that anything you consume outside the firewall is actually “in the cloud”. Nonetheless, the ability to increase capacity or add capabilities on the fly without the overheads of new infrastructure investments, software liscensing and personnel training cannot be ignored however you define it. Cloud computing encompasses any pay-per-use service or subscription-based service, in real time over the Internet. Cloud computing is simplification of usage and extension of the potentials, it’s about shifting more of your material out “there” and less on PCs or servers that a business runs for itself.
The maintenance burden of applications and servers is no longer going to be your personal heartburn. The capability of scaling systems up or down on demand, access to your data anytime from anywhere with an internet connection are some of the implications. The ability to replace occasional heavy expenditure on IT with regular and predictable operational expenditure is a management boon.
Nothing comes withhout it’s own inherent risks. Your provider’s downtime or insolvency means loss of your service. No control over how the data is protected poses security concerns. There are also issues concerning regulatory problems when personal data is stored internationally. One-sided service agreements and lock-in dependency on proprietary cloud applications can lead to uncomfortable situations for the user.Let’s have a look at some of the terms prevalent in Cloud Computing.
Pre-build applications like Google Mail and Google Docs which can be accessed by simply navigating to a particular url, belong to this category of Cloud Computing.
A set of API’s open for developers to hook into, and, providing them the ability to develop custom applications. They are basically a set of lower-level services such as an operating system/computer language interpreter/web server offered by a cloud provider. Google App Engine and Microsoft Azure are examples of PaaS.
IaaS (What is infrastructure-as-a-service)
Amazon’s Elastic Compute Cloud (EC2) is an example of IaaS. Servers or Virtual servers that can be used on a pay-as-you-go scheme are IaaS. Generally cloud suppliers provide add-on services too. Hence, very often, the definitions for PaaS and IaaS overlap.
An application like Salesforce.com where a single Cloud-hosted application is shared by a number of customers signify Multi-tenancy. Although the application is shared, obviously, each user has access to his own data. This is the most cost-effective form of Cloud computing.
Public, private and hybrid clouds
Providers like Google, Amazon and salesforce.com are public clouds. Here the shared services are open to all.By building a cloud-like infrastructure at your own data centre, the benefits of cloud computing can be reaped without the risk of a third party handling your data. This would be a Private cloud.A cloud which comprises a Private cloud and using a Public cloud too, would be categorised as a Hybrid cloud.
A peek into Amazon’s cloud computing platform
From it’s experience in the e-commerce domain, Amazon adapted the techniques for massive scaling it learnt and applied them to a service offered to others at commodity prices. Chief services include:1)Elastic Compute Cloud (EC2) for virtual servers running Linux or Windows2)Simple Storage Service (S3) for storing files in the cloud. Amazon also offers database and payment services. It is is a platform for developers.
A peek into Google’s cloud computing platform
Chief services include email, online documents like word processor, spreadsheet and presentation graphics – stored on the cloud and edited in the browser, payments and mapping services. It also offers a platform for Python and Java devlopers to build custom applications.
A peek into salesforce.com cloud computing platform
A multi- tenanted application for CRM (customer relationship management) is the core of the platform. An extension names as Force.com using it’s own programming language called Apex was plugged into it. Cloud computing may be thought of as a form of “sky computing” consisting of a number of isolated clouds of services, wherein customers must plug into individually. Although with the emergence of cloud computing aggregators and integrators, this requirement of ‘individually plugging into’ may be short-lived. With the advent of Service-Oriented-Architecture(SOA) and virtualisation in the enterprise, coupled with the concept of a scalable, agile infrastructure powering loosely coupled services, we may soon reach a stage where every enterprise is a node in the cloud.It’s still at a tender stage, but in the list of major metatrends, cloud computing is definitely in the Uppercase.