Cloud Computing

 What is Cloud Computing?

Everyone has an opinion on what is cloud computing. It can be the ability to rent a server

or a thousand servers and run a geophysical modelling application on the most powerful 

systems available anywhere. It can be the ability to rent a virtual server, load software on 

it, turn it on and off at will, or clone it ten times to meet sudden workload demand. It can 

be storing and securing immense amounts of data that is accessible only by authorized 

applications and users. 

It can be supported by a cloud provider that sets up a platform that includes the OS, 

Apache, a MySQL™ database, Perl, Python, and PHP with the ability to scale 

automatically in response to changing workloads. 

Cloud computing can be the ability to use applications on the Internet that store and 

protect data while providing a service — anything including email, sales force automation 

and tax preparation. It can be using a storage cloud to hold application, business, and 

personal data. And it can be the ability to use a handful of Web services to integrate 

photos, maps, and GPS information to create a mashup in customer Web browsers.

1.1.1 Definition

Cloud computing is the delivery of computing services over the Internet. Various 

computing services and resources such as servers, storage, databases, networking, 

software, analytics, and intelligence, can be provisioned over the Internet. The ability to 

dynamically allocate and deallocate the resources allows the user to scale as per need. 

Pay per use model adds an added advantage. Thus, the end-user can cut the operational 

cost and simply focus on other business needs.In brief cloud is essentially a bunch of 

commodity computers networked together in same or different geographical locations, 

operating together to serve a number of customers with different need and workload on 

demand basis with the help of virtualization. Cloud services are provided to the cloud users as utility services like water, electricity, telephone using pay-as-you-use business

model.

These utility services are generally described as XaaS (X as a Service) where X can be

Software or Platform or Infrastructure etc. Cloud users use these services provided by

the cloud providers and build their applications in the internet and thus deliver them to

their end users.

Cloud is essentially provided by large distributed data centers. These data centers are

often organized as grid and the cloud is built on top of the grid services. Cloud users are

provided with virtual images of the physical machines in the data centers. This

virtualization is one of the key concepts of cloud computing as it essentially builds the abstraction over the physical system.

Why Cloud Computing?

Let’s say your team has a terrific business idea. You plan to develop it technically,

showcase it your college. You are all set to go. Then all of a sudden, you hit a setback.

You do not have the necessary computing resources. You ask your teammates but no

luck there too. You desperately search for buying options but they are expensive. Since

they would be used for a very short span of time, it becomes even more infeasible. What

would you do?

Here comes the wonderful Cloud Computing. You realize you don’t have to buy these

resources. You can actually rent out these resources and the best part is that you don’t

even have to maintain the resources. The provider will do that too. This is why Cloud

Computing. You will pay according to the usage.

Basics of Cloud Computing.

Cloud Computing Basics

Cloud computing is a paradigm of distributed computing to provide the customers on￾demand, utility-based computing services. Cloud users can provide more reliable,

available and updated services to their clients in turn. Cloud itself consists of physical

machines in the data centres of cloud providers. Virtualization is provided on top of these

physical machines.

The cloud services are divided into many types like Software as a Service, Platform as a

Service or Infrastructure as a Service. These services are available over the Internet in

the whole world where the cloud acts as the single point of access for serving all

customers. Cloud computing architecture addresses difficulties of large-scale data

processing.

 Types of Cloud

The cloud provides 4 types of deployment models

1. Private Cloud – 

This type of cloud is maintained within an organization and used solely

for their internal purpose. So, the utility model is not a big term in this scenario. Many

companies are moving towards this setting and experts consider this is the 1st step for

an organization to move into cloud. Security, network bandwidth are not critical issues for

private cloud.

2. Public Cloud – In this type an organization rents cloud services from cloud provider’s

on-demand basis. Services provided to the users using utility computing model.

3. Community Cloud -- In this type, a specific community of consumer’s band together

to build a cloud. Similar to a private club cloud. More commonly talked about a decade

ago. Not a go-to concept of today.

4. Hybrid Cloud – This type of cloud is composed of multiple internal or external cloud.

This is the scenario when an organization moves to public cloud computing domain from its internal private cloud.