08-16-2017, 09:27 PM
Cloud Computing for Beginners
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What is Cloud Computing?
In late 90s or even now, ask any web developer, solution architect or anyone involved in web application development in any capacity:
Which symbol do you use to represent Internet on numerous white-board meetings? Obviously the most widely used metaphor for Internet was/is cloud. Cloud computing has derived its name from the same line of thinking.
Resource Sharing
Resource Sharing is the beauty of Cloud Computing. This is the concept which helps the cloud providers to attain optimum utilization of resources. Say, a company dealing in gifts may require more server resources during festive season. A company dealing in Payroll management may require more resources during the end or beginning of the month.
Infrastructure as a Service (IaaS)
This is the base layer of the cloud stack.
It serves as a foundation for the other two layers, for their execution. The keyword behind this stack is Virtualization.
Let us try to understand this using Amazon EC2. In Amazon EC2 (Elastic Compute Cloud) your application will be executed on a virtual computer (instance). You have the choice of virtual computer, where you can select a configuration of CPU, memory & storage that is optimal for your application. The whole cloud infrastructure viz. servers, routers, hardware based load-balancing, firewalls, storage & other network equipments are provided by the IaaS provider. The customer buy these resources as a service on a need basis.
Platform as a Service (PaaS)
Now you don t need to invest millions of $$ to get that development foundation ready for your developers. The PaaS provider will deliver the platform on the web, and in most of the cases you can consume the platform using your browser, i.e. no need to download any software. It has definitely empowered small & mid-size companies or even an individual developer to launch their own SaaS leveraging the power of these platform providers, without any initial investment.
Software as a Service (SaaS)
This is the Top most layer of the cloud computing stack - directly consumed by end user i.e. SaaS (Software as a Service).
On-Premise applications are quite expensive, affordable only to big enterprises. Why?
Cause On-Premise applications had a very high upfront CapEx(Capital Expenditure); which results in a high TCO (Total Cost of Ownership). On-Premise apps also require a higher number of skilled developers to maintain the application. In its current avatar SaaS is going to be the best bet for SMEs/SMBs (Small & Mid size businesses).