(Topics: Cluster Computing, Grid Computing, Grid Computing Versus Cloud Computing, Key Characteristics of Cloud Computing. Cloud Models: Benefits of Cloud Models, Public Cloud, Private Cloud, Hybrid Cloud, Community Cloud, Shared Private Cloud, Dedicated Private Cloud, and Dynamic Private Cloud.)

1. CLOUD COMPUTING
SWETA KUMARI BARNWAL 1
MODULE: 2
CLOUD MODELS
(Topics: Cluster Computing, Grid Computing, Grid Computing Versus Cloud Computing,
Key Characteristics of Cloud Computing. Cloud Models: Benefits of Cloud Models, Public
Cloud, Private Cloud, Hybrid Cloud, Community Cloud, Shared Private Cloud, Dedicated
Private Cloud, and Dynamic Private Cloud.)
Cluster Computing:
A Computer Cluster is a local network of two or more homogeneous (similar kind)
computers. A computation process on such a computer network i.e. cluster is called Cluster
Computing. Such a network is used when a resource hungry task requires high computing
power or memory.
Grid Computing:
Grid Computing can be defined as a network of homogeneous or heterogeneous computers
working together over a long distance to perform a task that would rather be difficult for a
single machine. Its target is to provide an environment where a task can be performed by
multiple computers together on need basis. Each computer can work independently as well.
Difference between Cluster & Grid Computing
Sr.
No.
Key Cluster Computing Grid Computing
1
Computer
Type
Nodes or computers has to be of
same type, like same CPU,
same OS. Cluster computing
needs a homogeneous network.
Nodes or computers can be of
same or different types. Grid
computer can have homogeneous
or heterogeneous network.
2
Task Computers of Cluster
Computing are dedicated to
single task and they cannot be
used to perform any other task.
Computers of Grid Computing
can leverage the unused
computing resources to do other
tasks.
3
Location Computers of Cluster
computing are co-located and
are connected by high speed
network bus cables.
Computers of Grid Computing
can be present at different
locations and are usually
connected by internet or a low
speed network bus.
4
Topology Cluster computing network is
prepared using a centralized
network topology.
Grid computing network is
distributed and have a de-
centralized network topology.
5
Task
Scheduling
A centralized server controls the
scheduling of tasks in cluster
computing.
In Grid Computing, multiple
servers can exist. Each node
behaves independently without

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Sr.
No.
Key Cluster Computing Grid Computing
need of any centralized
scheduling server.
6
Resource
Manager
Cluster Computing network has
a dedicated centralised resource
manager, managing the
resources of all the nodes
connected.
In Grid Computing, each node is
independently managing each
own resources.
7
Autonomy In Cluster computing network,
whole system works as a unit.
In Grid computing network, each
node is independent and can be
taken down or can be up at any
time without impacting other
nodes.
Key Characteristics of Cloud Computing
Basically there are 5 important characteristics of Cloud Computing.
1. On-demand self-services:
The Cloud computing services does not require any human administrators, user
themselves are able to provision, monitor and manage computing resources as
needed.
2. Broad network access:
The Computing services are generally provided over standard networks and
heterogeneous devices.
3. Rapid elasticity:
The Computing services should have IT resources that are able to scale out and
in quickly and on as needed basis. Whenever the user require services it is
provided to him and it is scale out as soon as its requirement gets over.
4. Resource pooling:
The IT resource (e.g., networks, servers, storage, applications, and services)
present are shared across multiple applications and occupant in an uncommitted
manner. Multiple clients are provided service from a same physical resource.
5. Measured service:
The resource utilization is tracked for each application and occupant, it will
provide both the user and the resource provider with an account of what has
been used. This is done for various reasons like monitoring billing and effective
use of resource.
Benefits:
Cloud computing has been around for approximately two decades and despite the data pointing
to the business efficiencies, cost-benefits, and competitive advantages it holds, a large portion
of the business community continues to operate without it. According to a study by the
International Data Group, 69% of businesses are already using cloud technology in one
capacity or another, and 18% say they plan to implement cloud-computing solutions at some

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point. At the same time, Dell reports that companies that invest in big data, cloud, mobility,
and security enjoy up to 53% faster revenue growth than their competitors. As this data shows,
an increasing number of tech-savvy businesses and industry leaders are recognising the many
benefits of the cloud-computing trend. But more than that, they are using this technology to
more efficiently run their organisations, better serve their customers, and dramatically increase
their overall profit margins. It operates on a similar principle as web-based email clients,
allowing users to access all of the features and files of the system without having to keep the
bulk of that system on their own computers. In fact, most people already use a variety of cloud
computing services without even realising it. Gmail, Google Drive, TurboTax, and even
Facebook and Instagram are all cloud-based applications. For all of these services, users are
sending their personal data to a cloud-hosted server that stores the information for later access.
And as useful as these applications are for personal use, they're even more valuable for
businesses that need to be able to access large amounts of data over a secure, online network
connection.
For example, employees can access customer information via cloud-based CRM software from
their smartphone or tablet or any other device at home or while traveling or from anywhere and
can quickly share that information with other authorized parties anywhere in the world. There
are several benefits:
a) Cost Savings
b) Security
c) Flexibility
d) Mobility
e) Insight
f) Increased Collaboration
g) Quality Control
h) Disaster Recovery
i) Loss Prevention
j) Automatic Software Updates
k) Competitive Edge
l) Sustainability
Classification of Cloud
Cloud can have any of the four types of access: Public, Private, Hybrid, and Community.

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Public Cloud
It allows systems and services to be easily accessible to the general public. Public cloud may
be less secure because of its openness. are managed by third parties which provide cloud
services over the internet to public, these services are available as pay-as-you-go billing mode.
They offer solutions for minimizing IT infrastructure costs and act as a good option for
handling peak loads on the local infrastructure. A fundamental characteristic of public clouds
is multitenancy. A public cloud is meant to serve multiple users, not a single customer. A user
requires a virtual computing environment that is separated, and most likely isolated, from
other users.
Private Cloud
It allows systems and services to be accessible within an organization. It is more secured
because of its private nature. It is a distributed systems that work on a private infrastructure
and providing the users with dynamic provisioning of computing resources. Instead of a pay-
as-you-go model as in public clouds, there could be other schemes in that take into account
the usage of the cloud and proportionally billing the different departments or sections of an
enterprise.

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• Dedicated Private Cloud (DPC): It is defined as physically isolated, single-tenant
collection of compute, network and sometimes storage resources exclusively
provisioned to just one organization or application. DPCs are scalable, isolated
computing environments that are tailored to fit unique requirements and rightsized for
any of workload or application. DPCs are ideal for mission-critical or legacy
applications. When applications can’t be easily refactored for the cloud, a DPC can be
a viable solution. DPC is also ideal for organizations seeking to reduce time spent
maintaining infrastructure. You do not need to sacrifice control, compliance or
performance with a DPC.
• Dynamic Private Cloud: “It is the ability for software and services to grow with your
business. Sometimes that means automatically adjusting itself to adjust to changes in
demand or workloads.” It business to be more agile in how it responds to changes in
the market. It allows a business to quickly develop through composing new
applications using prebuilt components. Dynamic cloud gives companies what they
need, where they need it and how and when they want it. Dynamic cloud is the
foundation of the composable business; it allows relentless innovation at the speed of
business.
Community Cloud
The community cloud allows systems and services to be accessible by a group of
organizations.

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Hybrid Cloud
The hybrid cloud is a mixture of public and private cloud, in which the critical activities are
performed using private cloud while the non-critical activities are performed using public
cloud. It is a heterogeneous distributed system resulted by combining facilities of public cloud
and private cloud. For this reason, it is also known as heterogeneous clouds. A major drawback
of private deployments is the inability to scale on demand and to efficiently address peak
loads. Here public clouds are needed. Hence, a hybrid cloud takes advantages of both public
and private cloud.