16-09-2016, 11:39 AM
[attachment=71090]
Abstract — These days cloud computing is booming
like no other technology. Every organization whether
it’s small, mid-sized or big, wants to adapt this cutting
edge technology for its business. As cloud technology
becomes immensely popular among these businesses,
the question arises: Which cloud model to consider for
your business? There are four types of cloud models
available in the market: Public, Private, Hybrid and
Community. This review paper answers the question,
which model would be most beneficial for your business.
All the four models are defined, discussed and compared
with the benefits and pitfalls, thus giving you a clear
idea, which model to adopt for your organization.
INTRODUCTION
Today, we can easily notice how the nature of the
Internet is changing from a place used to read web pages
to an environment that allows the users to run software
applications [1]. One vision of 21st century computing is
that users will access Internet services over lightweight
portable devices rather than through some descendant of
the traditional desktop PC. Because users won’t have (or
be interested in) powerful machines, who will supply the
computing power? The answer to this question lies with
cloud computing [2, 3]. Cloud computing is a distributed
computing paradigm that focuses on providing a wide
range of users with distributed access to scalable,
virtualized hardware and/or software infrastructure over
the internet [4]. Cloud computing has revolutionized the
information technology industry by enabling elastic ondemand
provisioning of computing resources [5]. Cloud
Computing is hinting at a future in which we won’t
compute on local computers, but on centralized facilities
operated by third-party compute and storage utilities [6].
Cloud computing paradigm has emerged as an energyefficient,
fault-tolerant and on-demand approach, which
enables ubiquitous network accesses to a shared pool of
flexibly reconfigurable computing resources. Networks,
servers, storage, applications and services can be rapidly
deployed with minimal management input or service
provider interaction [7]. Cloud Computing, the long-held
dream of computing as an utility, has the potential to
transform a large part of the IT industry, making software even more attractive as a service and shaping
the way IT hardware is designed and purchased. Cloud
computing refers to both the applications delivered as
services over the Internet and the hardware and systems
software in the datacenters that provide those services.
The services themselves have long been referred to as
Software as a Service. The datacenter hardware and
software is what we will call a cloud. When a cloud is
made available in a pay-as-you-go manner to the general
public, we call it a public cloud; the service being sold is
utility computing. We use the term private cloud to refer
to internal datacenters of a business or other
organization, not made available to the general public
[8]. Community cloud shares infrastructure between
several organizations [9]. Hybrid cloud provides the
flexibility of in-house applications with the fault
tolerance and scalability of cloud based services [10].
Several machines located around the world, which are
connected to a single network can be used for providing
cloud computing.
The paper is organized in IX sections. Section I gives
the introduction. Section II talks about the significance
of this study. Section III provides the overview of cloud
computing, followed by section IV, which discusses the
three service models of cloud computing in detail.
Section V, VI, VII and VIII define, discuss and review
the pros & cons of public, private, hybrid and
community clouds. The last section is conclusion, which
summarizes the key outcomes of this review.
II. SIGNIFICANE OF STUDY
More and more enterprises are adopting the cloud
model for their businesses, whether they are small, midsized
or large organizations, as cloud computing
provides low cost business solutions to their
organizations. It is a well known fact that every business
needs cloud, as the technology has become very popular
and accepted world over. Cloud computing has promised
tremendous advantages to organizations in terms of cost
effectiveness, operational excellence and innovation.
The main factor for which enterprises are shifting to
cloud is the low cost. Cloud helps to turn substantial
investments into operational expenses, reduce man
management costs, operational costs and maintenance
costs. Start-ups and small & mid businesses (SMBs)
take particular interest in public cloud as they have
limited investments and resources. Instead, big organizations prefer private cloud. This review paper
covers the concerns of enterprises in adopting public,
private, hybrid, and community clouds for their
respective organizations, and lists the differences among
them, thus providing a complete idea which model
would be better for their enterprises.
III. OVERVIEW OF CLOUD COMPUTING
Cloud computing is a model for enabling ubiquitous,
convenient, on-demand network access to a shared pool
of configurable computing resources (e.g., networks,
servers, storage, applications, and services) that can be
rapidly provisioned and released with minimal
management effort or service provider interaction. This
cloud model promotes availability and is composed of
five essential characteristics, three service models, and
four deployment models [9]. Cloud computing has three
basic abstraction layers, i.e, system layer (which is a
virtual machine abstraction of a server), the platform
layer (a virtualized operating system of a server) and
application layer (that includes web applications) [11].
Computing is being transformed to a model consisting of
services that are commoditized and delivered in a
manner similar to traditional utilities such as water,
electricity, gas, and telephony [12]. The cloud
computing service model involves the provision, by a
service provider, of large pools of high performance
computing resources and high-capacity storage devices
that are shared among end users as required [13-15].
Cloud computing potentially offers an overall financial
benefit, in that end users share a large, centrally
managed pool of storage and computing resources,
rather than owning and managing their own systems [16].
Cloud service providers invest in the necessary
infrastructure and management systems, and in return
receive a time-based or usage-based fee from end users
[17]. Cloud computing is emerging today as a
commercial infrastructure that eliminates the need for
maintaining expensive computing hardware. Through
the use of virtualization, clouds promise to address with
the same shared set of physical resources a large user
base with different needs. Thus, clouds promise for
scientists to be an alternative to clusters, grids, and
supercomputers [18]. Cloud computing systems
fundamentally provide access to large pools of data and
computational resources through a variety of interfaces
[19-24]. However, despite the fact that cloud computing
offers huge opportunities to the IT industry, the
development of cloud computing technology is currently
at its infancy, with many issues still to be addressed [25-
28]. Cloud computing is the long dreamed vision of
computing as a utility, where users can remotely store
their data into the cloud so as to enjoy the on-demand
high quality applications and services from a shared pool
of configurable computing resources. By data
outsourcing, users can be relieved from the burden of
local data storage and maintenance [29]. With the
technology, users on various types of devices—
including PCs, laptops, smart phones, and PDAs—
access programs, storage, processing, and even
application-development platforms over the Internet, via
services offered by cloud-computing providers [30]. The
data you can find in a cloud ranges from public source,
which has minimal security concerns, to private data
containing highly sensitive information (such as social
security numbers, medical records, or shipping manifests
for hazardous material) [31-44]. Authentication of both
users and services is a significant issue for the trust and
security of the cloud computing [45-46]. As promising
as it is, cloud also brings forth many new challenges for
data security and access control when users outsource
sensitive data for sharing on cloud servers, which are not
within the same trusted domain as data owners. To keep
sensitive user data confidential against un-trusted servers,
existing solutions usually apply cryptographic methods
by disclosing data decryption keys only to authorized
users [47-60]. Cloud data storage is a technology that
uses the internet and central remote servers to maintain
data and share the applications. It allows consumer to
use applications without installation and access their
personal files at any computer with internet access. In
general data property analysis system, source and
destination file content is compared in the form of bytes.
In the cloud environment, data verification is needed for
every computation in the storage correctness. So every
time the data is retrieved from local system and
compared with the destination file from the cloud zone
[61-63]. In cloud environment, a client device or other
processing device comprises a file processing module,
with the file processing module being operative to
request proof from a file system that a file having a first
format is stored by the file system in a second format
different than the first format, to receive the proof from
the file system, and to verify that the file is stored in the
second format using the proof provided by the file
system responsive to the request. The proof is based at
least in part on application of a function to the file in the
second format, and the function imposes a minimum
resource requirement on generation of the proof. The file
system may comprise one or more servers associated
with a cloud storage provider. Advantageously, one or
more illustrative embodiments allow a client device to
verify that its files are stored by a cloud storage provider
in encrypted form or with other appropriate protections
Abstract — These days cloud computing is booming
like no other technology. Every organization whether
it’s small, mid-sized or big, wants to adapt this cutting
edge technology for its business. As cloud technology
becomes immensely popular among these businesses,
the question arises: Which cloud model to consider for
your business? There are four types of cloud models
available in the market: Public, Private, Hybrid and
Community. This review paper answers the question,
which model would be most beneficial for your business.
All the four models are defined, discussed and compared
with the benefits and pitfalls, thus giving you a clear
idea, which model to adopt for your organization.
INTRODUCTION
Today, we can easily notice how the nature of the
Internet is changing from a place used to read web pages
to an environment that allows the users to run software
applications [1]. One vision of 21st century computing is
that users will access Internet services over lightweight
portable devices rather than through some descendant of
the traditional desktop PC. Because users won’t have (or
be interested in) powerful machines, who will supply the
computing power? The answer to this question lies with
cloud computing [2, 3]. Cloud computing is a distributed
computing paradigm that focuses on providing a wide
range of users with distributed access to scalable,
virtualized hardware and/or software infrastructure over
the internet [4]. Cloud computing has revolutionized the
information technology industry by enabling elastic ondemand
provisioning of computing resources [5]. Cloud
Computing is hinting at a future in which we won’t
compute on local computers, but on centralized facilities
operated by third-party compute and storage utilities [6].
Cloud computing paradigm has emerged as an energyefficient,
fault-tolerant and on-demand approach, which
enables ubiquitous network accesses to a shared pool of
flexibly reconfigurable computing resources. Networks,
servers, storage, applications and services can be rapidly
deployed with minimal management input or service
provider interaction [7]. Cloud Computing, the long-held
dream of computing as an utility, has the potential to
transform a large part of the IT industry, making software even more attractive as a service and shaping
the way IT hardware is designed and purchased. Cloud
computing refers to both the applications delivered as
services over the Internet and the hardware and systems
software in the datacenters that provide those services.
The services themselves have long been referred to as
Software as a Service. The datacenter hardware and
software is what we will call a cloud. When a cloud is
made available in a pay-as-you-go manner to the general
public, we call it a public cloud; the service being sold is
utility computing. We use the term private cloud to refer
to internal datacenters of a business or other
organization, not made available to the general public
[8]. Community cloud shares infrastructure between
several organizations [9]. Hybrid cloud provides the
flexibility of in-house applications with the fault
tolerance and scalability of cloud based services [10].
Several machines located around the world, which are
connected to a single network can be used for providing
cloud computing.
The paper is organized in IX sections. Section I gives
the introduction. Section II talks about the significance
of this study. Section III provides the overview of cloud
computing, followed by section IV, which discusses the
three service models of cloud computing in detail.
Section V, VI, VII and VIII define, discuss and review
the pros & cons of public, private, hybrid and
community clouds. The last section is conclusion, which
summarizes the key outcomes of this review.
II. SIGNIFICANE OF STUDY
More and more enterprises are adopting the cloud
model for their businesses, whether they are small, midsized
or large organizations, as cloud computing
provides low cost business solutions to their
organizations. It is a well known fact that every business
needs cloud, as the technology has become very popular
and accepted world over. Cloud computing has promised
tremendous advantages to organizations in terms of cost
effectiveness, operational excellence and innovation.
The main factor for which enterprises are shifting to
cloud is the low cost. Cloud helps to turn substantial
investments into operational expenses, reduce man
management costs, operational costs and maintenance
costs. Start-ups and small & mid businesses (SMBs)
take particular interest in public cloud as they have
limited investments and resources. Instead, big organizations prefer private cloud. This review paper
covers the concerns of enterprises in adopting public,
private, hybrid, and community clouds for their
respective organizations, and lists the differences among
them, thus providing a complete idea which model
would be better for their enterprises.
III. OVERVIEW OF CLOUD COMPUTING
Cloud computing is a model for enabling ubiquitous,
convenient, on-demand network access to a shared pool
of configurable computing resources (e.g., networks,
servers, storage, applications, and services) that can be
rapidly provisioned and released with minimal
management effort or service provider interaction. This
cloud model promotes availability and is composed of
five essential characteristics, three service models, and
four deployment models [9]. Cloud computing has three
basic abstraction layers, i.e, system layer (which is a
virtual machine abstraction of a server), the platform
layer (a virtualized operating system of a server) and
application layer (that includes web applications) [11].
Computing is being transformed to a model consisting of
services that are commoditized and delivered in a
manner similar to traditional utilities such as water,
electricity, gas, and telephony [12]. The cloud
computing service model involves the provision, by a
service provider, of large pools of high performance
computing resources and high-capacity storage devices
that are shared among end users as required [13-15].
Cloud computing potentially offers an overall financial
benefit, in that end users share a large, centrally
managed pool of storage and computing resources,
rather than owning and managing their own systems [16].
Cloud service providers invest in the necessary
infrastructure and management systems, and in return
receive a time-based or usage-based fee from end users
[17]. Cloud computing is emerging today as a
commercial infrastructure that eliminates the need for
maintaining expensive computing hardware. Through
the use of virtualization, clouds promise to address with
the same shared set of physical resources a large user
base with different needs. Thus, clouds promise for
scientists to be an alternative to clusters, grids, and
supercomputers [18]. Cloud computing systems
fundamentally provide access to large pools of data and
computational resources through a variety of interfaces
[19-24]. However, despite the fact that cloud computing
offers huge opportunities to the IT industry, the
development of cloud computing technology is currently
at its infancy, with many issues still to be addressed [25-
28]. Cloud computing is the long dreamed vision of
computing as a utility, where users can remotely store
their data into the cloud so as to enjoy the on-demand
high quality applications and services from a shared pool
of configurable computing resources. By data
outsourcing, users can be relieved from the burden of
local data storage and maintenance [29]. With the
technology, users on various types of devices—
including PCs, laptops, smart phones, and PDAs—
access programs, storage, processing, and even
application-development platforms over the Internet, via
services offered by cloud-computing providers [30]. The
data you can find in a cloud ranges from public source,
which has minimal security concerns, to private data
containing highly sensitive information (such as social
security numbers, medical records, or shipping manifests
for hazardous material) [31-44]. Authentication of both
users and services is a significant issue for the trust and
security of the cloud computing [45-46]. As promising
as it is, cloud also brings forth many new challenges for
data security and access control when users outsource
sensitive data for sharing on cloud servers, which are not
within the same trusted domain as data owners. To keep
sensitive user data confidential against un-trusted servers,
existing solutions usually apply cryptographic methods
by disclosing data decryption keys only to authorized
users [47-60]. Cloud data storage is a technology that
uses the internet and central remote servers to maintain
data and share the applications. It allows consumer to
use applications without installation and access their
personal files at any computer with internet access. In
general data property analysis system, source and
destination file content is compared in the form of bytes.
In the cloud environment, data verification is needed for
every computation in the storage correctness. So every
time the data is retrieved from local system and
compared with the destination file from the cloud zone
[61-63]. In cloud environment, a client device or other
processing device comprises a file processing module,
with the file processing module being operative to
request proof from a file system that a file having a first
format is stored by the file system in a second format
different than the first format, to receive the proof from
the file system, and to verify that the file is stored in the
second format using the proof provided by the file
system responsive to the request. The proof is based at
least in part on application of a function to the file in the
second format, and the function imposes a minimum
resource requirement on generation of the proof. The file
system may comprise one or more servers associated
with a cloud storage provider. Advantageously, one or
more illustrative embodiments allow a client device to
verify that its files are stored by a cloud storage provider
in encrypted form or with other appropriate protections