Private Vs Public Cloud

Abstract

The main objective of the Private Cloud Hosting platforms is to optimize IT resources involved in the cycle of corporate provisioning, delivery, monitoring and control of business-critical applications: the elasticity of supply storage, processing and networking, on-demand access to systems, self-provisioning by the user or workgroup, through a centralized management dashboard unified system administrators, workgroup managers and end users. The decision to pursue cloud computing is one that many organization have or will make as this technology grows and matures. But this decision need not be one fraught with uncertainty. With a little due diligence, and answering a few key questions, you can ensure that your cloud vendor selection is a sound one. Nature of public cloud architecture depends upon sharing and accessing data within inhouse It premises as well as third parties. Although, this type of cloud form does raises an alarm in terms of security, but is equally efficient like private cloud architecture. Factors like scaled up environment and bandwidth uptime is also catered in this type of cloud form.

Full text

Private Vs Public Cloud
Solanke Vikas 1, Kulkarni Gurudatt 2, Maske Vishnu 3 , Kumbharkar Prashant 4
1 Lecturer in Information Technology Department,MM Polytechnic Pune, India
solankevs@mmpolytechnic.com
2 Lecturer in Electronic and Telecommunication Department,MM Polytechnic Pune, India,
kulkarniga@mmpolytechnic.com
3 Lecturer in Computer Department, Government Polytechnic, Mumbai, India.
vdmaske@yahoo.com
4 Head of Computer Department,Siddhant College Of Engineering, Pune, India.
Abstract
The main objective of the Private Cloud Hosting
platforms is to optimize IT resources involved in the
cycle of corporate provisioning, delivery, monitoring
and control of business-critical applications: the
elasticity of supply storage, processing and networking,
on-demand access to systems, self-provisioning by the
user or workgroup, through a centralized management
dashboard unified system administrators, workgroup
managers and end users. The decision to pursue cloud
computing is one that many organization have or will
make as this technology grows and matures. But this
decision need not be one fraught with uncertainty. With
a little due diligence, and answering a few key
questions, you can ensure that your cloud vendor
selection is a sound one. Nature of public cloud
architecture depends upon sharing and accessing data
within inhouse It premises as well as third parties.
Although, this type of cloud form does raises an alarm
in terms of security, but is equally efficient like private
cloud architecture. Factors like scaled up environment
and bandwidth uptime is also catered in this type of
cloud form.
Keyword: - Public, Hybrid, Offline, Platform.
.
1.0 What is Cloud Computing?
Cloud computing broadly describes off-premise,
ondemand computing where the end-user is provided
applications, computing resources, and services
(including operating systems and infrastructure) by
clouds services provider via the Internet. The hosting
industry came out of the need for software and
computing services that were managed internally, but
were made more economical and accessible through the
economies of scale of a hosted implementation.Cloud
computing as a computing model, not a technology. In
this model “customers” plug into the “cloud” to access
IT resources which are priced and provided “on-
demand”. Essentially, IT resources are rented and
shared among multiple tenants much as office space,
apartments, or storage spaces are used by tenants.
Delivered over an Internet connection, the “cloud”
replaces the company data center or server providing
the same service. Thus, Cloud Computing is simply IT
services sold and delivered over the Internet[9,8].
2.0 CLASSIFICATION OF CLOUDS:-
Cloud Computing can be classified into 4 types on the
basis of location where the cloud is hosted:
 Public Cloud: Computing infrastructure is
hosted at the vendor’s premises. The customer
has no visibility over the location of the cloud
computing infrastructure. The computing
infrastructure is shared between organizations.
 Private Cloud: Computing architecture is
dedicated to the customer and is not shared
with other organizations. They are expensive
and are considered more secure than Public
Clouds. Private clouds may be externally
hosted ones as well as in premise hosted
clouds.
 Hybrid Cloud: Organizations host some
critical, secure applications in private clouds.
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The not so critical applications are hosted in
the public cloud. The combination is known as
Hybrid Cloud. Cloud bursting is the term used
to define a system where the organization uses
its own infrastructure for normal usage, but
cloud is used for peak loads.
 Community Cloud: The cloud infrastructure is
shared between the organizations of the same
community. For example, all the government
agencies in a city can share the same cloud but
not the non government agencies.
3.0 Public Cloud Vs Private Cloud
 Public cloud is used as a service via Internet by
the users, whereas a private cloud, as the name
conveys is deployed within certain boundaries like
firewall settings and is completely managed and
monitored by the users working on it in an
organization.
 Users have to pay a monthly bill for public cloud
services, but in private cloud money is charged
on the basis of per GB usage along with
bandwidth transfer fees.
 Public cloud functions on the prime principle of
storage demand scalability, which means it requires no
hardware device. On the contrary, no hardware is
required even in private cloud, but the data stored in the
private cloud can only be shared amongst users of an
organization and third party sharing depends upon trust
they build with them. It is also entirely monitored by
the business entity where it is running.
The following diagram reviews the differences
between public and private clouds:
Any enterprises are beginning their cloud evaluation
with a "private cloud." I extend the definition of private
cloud to be a "single tenant" cloud, as some enterprises
may chose to use a single tenant cloud hosted at a
service provider, versus hosting their cloud within their
own data centers. In the following diagram, we show
two private clouds, connected via policy-based
replication in two data centers. This provides the
assurance of backup and disaster recovery that many
enterprises require. A third location could easily be
added for even higher levels of backup and disaster
recovery.
The growth of storage is driving increased costs, and
the enterprise is on a continuous search to improve the
way they can cost-effectively manage this growing
data. The primary difference between hybrid cloud and
private cloud is the extension of service provider-
oriented low cost cloud storage to the enterprise. The
service provider based cloud may be a private cloud
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(single tenant) or a public cloud (multi-tenant). There
are several implementations of hybrid cloud, and
several examples are included. The service provider
cloud may enable enterprises to leverage the volume
efficiencies of the service providers to realize
additional savings. The private cloud, or enterprise
cloud, is where the infrastructure is created or set up
solely for one organization. Management of the
infrastructure can be done in the comfort of the site of
the organization itself. But if the company chooses, it
can also be managed offsite, either as a hosted or
managed cloud, by a service provider. Public cloud, on
the other hand, is the type of infrastructure that serves a
number of tenants. Most of the tenants are small scale
businesses and the general public. The ownership of the
resources is in the hands of the business that sells the
service. When it comes to privacy and security, it is the
private cloud that works best. One can be sure that all
data and information are secure. This is especially great
for companies that do specialized research and
development or those that work for the government.
Furthermore, additional security measures may be
installed. Also companies with huge databases can
greatly benefit from using the private cloud. On the
issue of scalability, the public cloud is more efficient.
Unlike the private cloud whose scalability potential is
restricted or limited due to the company’s limited
emises, the public cloud shares more common
resources which make it more scalable. The client
business does not have to worry about additional
servers as this is the job of the provider. Virtualization
knowledge is another issue to consider. Though there
have been attempts at creating a company’s own
private cloud, the problem comes in when there is the
lack of expertise and experience of the employees. The
staff that handles this area should be knowledgeable.
This is not a problem for the public cloud. Another
important consideration is pricing. The private cloud is,
obviously, more costly that the other one. If the
company does not need the advanced security features
and network latency, then the public cloud will do as it
is more affordable. And for now, what is most
necessary to do for companies is to start transferring
their files to the cloud and be able to compete with the
rest of the business world. The majority of public cloud
deployments are generally used for web servers or
development systems where security and compliance
requirements of larger organizations and their
customers is not an issue. Private cloud computing, on
the other hand, by definition is a single-tenant
environment where the hardware, storage and network
are dedicated to a single client or company. The public
cloud is defined as a multi-tenant environment, where
you buy a “server slice” in a cloud computing
environment that is shared with a number of other
clients or tenants.
3.1 PUBLIC CLOUDS AMAZON EC2 AND
ACKSPACE CLOUD TRADEOFFS [1,
2]
 Utility Model – Public Clouds typically deliver a
pay-as-you-go model, where you pay by the
hour for the computer resources you use. This is
an economical way to go if you’re spinning up &
tearing down development servers on a regular
basis.
 No Contracts – Along with the utility model,
you’re only paying by the hour – if you want to
shut down your server after only 2 hours of use,
there is no contract requiring your ongoing use
of the server.
 Shared Hardware – Because the public cloud is
by definition a multi-tenant environment, your
server shares the same hardware, storage and
network devices as the other tenants in the cloud.
Meeting compliance requirements, such as PCI
or SOX, is not possible in the public cloud. No
Control of Hardware Performance – In the
public cloud, you can’t select the hardware,
cache or storage performance (SATA or SAS).
Your virtual server is placed on whatever
hardware and network, the public cloud provider
designates for you.
 Self Managed – with the high volume, utility
model, self managed systems are required for
this business model to make sense. Advantage
here for the technical buyers that like to setup
and manage the details of their servers.
Disadvantage for those that want a fully
managed solution.
 The majority of public cloud deployments are
generally used for web servers or development
systems where security and compliance
requirements of larger organizations and their
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ISSN:2249-5789

customers is not an issue. Private cloud hosting,
on the other hand, by definition is a single-tenant
environment where the hardware, storage and
network are dedicated to a single client or
company.
3.2 PRIVATE CLOUD COMPUTING
TRADES-OFFS: [2]
 Security – Because private clouds are
dedicated to a single organization, the
hardware, data storage and network can be
designed to assure high levels of security that
cannot be accessed by other clients in the
same data center.
 Compliance – Sarbanes Oxley, PCI and
HIPAA compliance cannot be delivered
through a public cloud deployment. Because
the hardware, storage and network
configuration is dedicated to a single client,
compliance is much easier to achieve.
 Customizable – Hardware performance,
network performance and storage performance
can be specified and customized in the private
cloud.
 Hybrid Deployments – If a dedicated server is
required to run a high speed database
application, that hardware can be integrated
into a private cloud, in effect, hybridizing the
solution between virtual servers and dedicated
servers. This can’t be achieved in a public
cloud.
3.2 CHALLENGES OF A PRIVATE
CLOUD [1]
There are a few constraints and challenges that would
make the public cloud model more appealing to a lot of
organizations. There are inherent challenges with
private cloud that need to be addressed before an
organization can venture down the path of building
one.
1. Upfront Capital Cost: One of the drawbacks of
private clouds is that organizations still need
to buy, build and manage the cloud
infrastructure, which defeats the primary
premise of cloud computing. One of the key
value propositions of cloud computing is that
it drastically reduces the upfront capital cost of
in-house infrastructure, while providing the
same or better service for a simple recurring
operational cost. This benefit cannot be
realized with private cloud infrastructures.
2. Time and Resources: Not all organizations
have the time or resources with in-house
expertise to build the infrastructure and
automation required to stand up and operate a
private cloud. Case studies show that it
involves much up-front investment in time and
resources compared to simply going with a
public cloud. However, there are many up and
coming startups that are offering private cloud
related services and products that
organizations can use in their internal data
center. While these products still need time to
mature and become mainstream, this
represents a significant shift towards the
availability of the technology required to
install and manage private cloud computing
infrastructures. These product and service
offerings could mitigate some of the risks and
challenges and blur the line between a private
and public cloud.
3. Size of the organization: Not all organizations
can afford to build a private cloud for the two
reasons listed above. Crafting a business case
for building a private cloud for a smaller
organization is difficult, since building the in
house infrastructure for the private cloud does
not provide as much of a return on investment
as larger cloud deployments do. The public
cloud provides impressive benefits related to
economies of scale, and smaller organizations
will find it difficult to build a private cloud
solution that can match that.
CONCLUSION
A private cloud, because it functions independently
for an organization and that too behind firewall settings
does prove to be accessible. By stating this, we mean
that a private cloud cannot be accessed from anywhere
and at any point of time. It is completely managed by
the users working for an organization. Public cloud
architecture is built with the view to create an
accessible business environment that can be shared and
accessed from anywhere and at any time of the hour.
Even though, it poses security risks, public cloud is
considered more useful than its counterpart because of
several reasons, Initial cost is minimal, but if data is
stored for a long period of time, it proves to be
expensive. However, the cloud acts as an excellent
source for different types of data than a particular type
of it. More accessible than the private cloud as it can be
accessed from anywhere round the globe. Availability
and reliability are the two factors that make public
cloud computing service more popular. The reason
being, it is available to users via web installed at a
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ISSN:2249-5789

given server off-premises. Public cloud’s advantage
includes low upfront cost, with practically infinite
scalability, it has a significant downside especially in
accountability, security, and lock-in.
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