Introduction of Cloud Computing
Cloud Computing simply means
Internet computing. The internet is
commonly visualized as clouds, hence the cloud computing for computation done
through internet. With cloud computing user can easily access database, software
resource via internet from anywhere, without worrying about maintenance and
management of database in cloud. It is a very independent platform in terms of
computing, databases in the cloud are very dynamic and scalable.
In other words, cloud computing
means getting the best performing system with the best value of money. Cloud
computing is a general term for anything that involves delivering hosted
services over the internet. These services are broadly divided into three
categories: Infrastructure as a Service (IaaS),
Platform as a Service (PaaS) and
Software as a Service (SaaS).
Cloud computing is cost effective. Here, cost is greatly reduced as initial
expense and recurring expenses are much lower than the traditional computing.
Maintenance cost is reduced as a third party maintains everything from running
the cloud to storing data.
Cloud is characterized by features such as platform, location and device
independency, which makes it easily adoptable for all size of business.
Another most important characteristic of cloud is scalability, which is achieved
through server virtualization.
Architecture of Cloud Computing:
Cloud computing architecture,
just like other system is categorized into two main sections: frontend and
backend. Frontend can be end user or client or any application (i.e. web browser
etc.) which is using cloud services. Backend is the network of server with any
computer program and data storage system. It is usually assumed that cloud
contains infinite storage capacity for any software available in the market.
Once a cloud is established, how
its cloud computing services are deployed in terms of business model can differ
depending on their requirement. The primarily service model being deployed are
commonly known as:
Software as a Service: SaaS is a software model provided by the vendor through
an online service. User doesn’t have to install or maintain SaaS application.
Software is running on a provider’s cloud infrastructure and a user can access
it via web browser. With SaaS, vendor makes the required software available to a
business on subscription basis, and charges are based on the product usage. SaaS
model can save the companies expenses
on buying hardware and software and it removes the maintenance costs.
Platform as a Service:
enables companies to develop applications more quickly and efficiently in a
cloud environment using programming languages and tools supported by the
provider. The provider is responsible for maintenance and control of the
underlying cloud infrastructure including network, servers, and operating
systems. PaaS services provide a great deal of flexibility allowing companies to
build PaaS environments on demand with no capital expenditures.
Infrastructure as a Service:
a company can rent fundamental computing resources for deploying and running
applications or storing data. It enables companies to deliver applications more
efficiently by removing the complexities involved with managing their own
infrastructure. IaaS enables fast deployment of applications, and improves the
ability of IT services by instantly adding computing processing power and
storage capacity when needed.
The cloud infrastructure has been deployed, and
is maintained and operated for a specific organization. The operation may be
in-house or with a third party on the premises.
The cloud infrastructure is
shared among a number of organizations with similar interests and requirements.
This may help limit the capital expenditure costs for its establishment as the
costs are shared among the organizations. The operation may be in-house or with
a third party on the premises.
The cloud infrastructure is available to the
public on a commercial basis by a cloud service provider. This enables a
consumer to develop and deploy a service in the cloud with very little financial
outlay compared to the capital expenditure requirements normally associated with
other deployment options.
The cloud infrastructure consists of a number of
clouds of any type, but the clouds have the ability through their interfaces to
allow data and/or applications to be moved from one cloud to another. This can
be a combination of private and public clouds that support the requirement to
retain some data in an organization, and also the need to offer services in the
The following are some of the
possible benefits for those who offer cloud computing-based services and
Companies can reduce their capital expenditures
and use operational expenditures for increasing their computing capabilities.
This is a lower barrier to entry and also requires fewer in-house IT resources
to provide system support.
Companies can start with a small deployment and
grow to a large deployment fairly rapidly, and then scale back if necessary.
Also, the flexibility of cloud computing allows companies to use extra resources
at peak times, enabling them to satisfy consumer demands.
Services using multiple
redundant sites can support business continuity and disaster recovery.
Cloud service providers do the
system maintenance, and access is through APIs that do not require application
installations onto PCs, thus further reducing maintenance requirements.
Mobile workers have increased productivity due to systems accessible in an
infrastructure available from anywhere.