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A Survey on Cloud Computing Services

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					   International Journal of Emerging Trends & Technology in Computer Science (IJETTCS)
       Web Site: www.ijettcs.org Email: editor@ijettcs.org, editorijettcs@gmail.com
Volume 1, Issue 4, November – December 2012                                    ISSN 2278-6856




              A Survey on Cloud Computing Services
                                                  Vincy goyal1, Ruchi dave2
                      1, 2
                             Suresh Gyan Vihar University, Gyan Vihar School Of Engineering & Technology
                                                  Mahal, Jagatpura, Jaipur, India



Abstract: Cloud computing is a computing platform where a
large pool of systems are connected in private or public
networks, to provide dynamically scalable infrastructure for
application, data and file storage. It shares computer
resources instead of using software or storage on a local PC
at a vast level. In the last few years, it is the growing
acceptance of innovative technologies that has seen cloud
computing become the biggest buzzword in IT. This paper
outlines the key features that cloud computing technologies
possess and illustrates the three essential services (SaaS,
PaaS and IaaS) and deployment model. The future of cloud
computing along with its challenges is also explored.
Keyword: Cloud computing, SaaS, PaaS, IaaS.

1. INTRODUCTION
Cloud computing is an emerging computing technology                        Figure 1: Cloud Computing Scenario [4]
that uses the internet and central remote servers to
maintain data and applications. This technology allows
for much more efficient computing by centralizing                 2. CLOUD COMPUTING SERVICE MODELS
storage, memory, processing and bandwidth. [1] Perhaps
the simplest working definition of cloud computing is             In cloud computing, everything is delivered as a Service
“being able to access files, data, programs and 3rd party         (XaaS), from testing and security, to collaboration and
services from a Web browser via provider”[2] and                  metamodeling. [7] There are three types of service models
“paying only for the computing resources and services             which are described in the following:
used”. The term "Cloud Computing" has been mentioned              2.1 Software as a Service (SaaS)
for just under four years in relation to services or              It provides users an easier way to access many of their
infrastructural resources, which can be contracted over a         standard business applications and services such as email
network. Thus, the idea of renting instead of buying IT is        and word processing packages etc, by allowing users to
nothing new. And so, Cloud Computing has many                     access these programs through the internet, there is no
antecedents and equally as many attempts to define it.            need to install and run the special software on your
The players in the large world of clouds are Software as a        computer if you use the SaaS. The applications are
Services provider, outsourcing and hosting providers,             accessible from various client devices through either a
network and IT infrastructure providers and, above all,           thin client interface, such as a web browser (e.g., web-
the companies whose names are closely linked with the             based email), or a program interface. User-clients just use
Internet's commercial boom. But, all these services in            this service without the headache of running,
combination outline the complete package known as                 maintaining, updating the software. It will help to get rid
Cloud Computing – depending on the source with the                of cost complexity because end users need not to worry
appropriate focus. [3]the Internet that are hosted by a 3rd       about all those things.[8] Examples of SaaS are
party From IBM vision, Cloud is a computing model                 Salesforce.com, Google’s Gmail, Microsoft’s Office Live
providing web-based software, middleware and                      and Cornerstone On Demand etc.
computing resources on demand. [5] National Institute of
                                                                  2.2 Platform as a Service(PaaS)
Standards and Technology (NIST) defined Cloud
                                                                  This is where applications are developed using a set of
Computing as a model for enabling convenient, on-
                                                                  programming languages and tools that are supported by
demand network access to a shared pool of configurable
                                                                  the PaaS provider. It allows users to use cloud computing
computing resources (e.g., networks, servers, storage,
                                                                  for developing any application using development kit
applications, and services) that can be rapidly provisioned
                                                                  provided by cloud computing. Users are not required to
and released with minimal management effort or service
                                                                  install development kit on local machine, he can use
provider interaction. [6]
                                                                  installed software or development kit in cloud computing

Volume 1, Issue 4 November - December 2012                                                                        Page 111
   International Journal of Emerging Trends & Technology in Computer Science (IJETTCS)
       Web Site: www.ijettcs.org Email: editor@ijettcs.org, editorijettcs@gmail.com
Volume 1, Issue 4, November – December 2012                                    ISSN 2278-6856


to develop any program [9]. The client has the freedom to    Internet. Services can be dynamically provisioned and are
create his own applications, which run on the provider’s     billed based on usage alone. This model provides the
infrastructure. It delivers web-based (cloud) applications   highest degree of cost savings while requiring the least
without the cost and complexity of buying and managing       amount of overhead. [13]
the underlying hardware, software, provisioning and          3.2 Private Cloud
hosting. [10] There are many examples of PaaS such as        It describes computer services delivered to a single
Google’s App Engine, Amazon’s EC2 and Microsoft’s            organization. They aim to address concerns on data
Azure platform.                                              security and offer greater control, which is typically
2.3 Infrastructure as a Service(IaaS)                        lacking in a public cloud. This model shares many of the
Infrastructure as a Service enables us to install and        characteristics of a traditional client-server architecture,
execute the software. Here, users can gain access to         while integrating features associated with other models
virtualized server. IaaS targets operating systems,          cloud computing.[13] It is mostly suited for sensitive
hardware, CPUs and embedded systems, networks and            data, where the customer is dependent on a certain degree
storage. This enables a homogenous virtualized               of security[14]. Quality of Service (QoS) is managed and
environment where specific software will be installed and    controlled by the organization itself. For example,
executed [9]. The consumer does not manage or control        Amazon Virtual Private Cloud (VPC) is a private cloud,
the underlying cloud infrastructure but has control over     which offers clients isolated AWS (Amazon Work Space)
operating systems, storage, and deployed applications;       and protection by Virtual Private Network (VPN)
and possibly limited control of select networking            connections.
components (e.g., host firewalls). [11] IaaS provides        3.3 Hybrid Cloud
companies with computing resources including servers,        The cloud infrastructure is a composition of two or more
networking, storage, and data center space on a pay-per-     clouds (private, community, or public) that remain unique
use basis. [10] Some of the most popular examples of         entities but are bound together by standardized or
IaaS include Go Grid’s ServePath and Amazon’s Elastic        proprietary technology that enables data and application
Compute Cloud (EC2).                                         portability. It helps businesses to take advantage of
                                                             secured applications and data hosting on a private cloud,
                                                             while still enjoying cost benefits by keeping shared data
                                                             and applications on the public cloud. [15] It is capable of
                                                             providing on-demand, externally provisioned scale.
                                                             3.4 Community Cloud
                                                             The community cloud is restricted and utilize with a set
                                                             of group that comprise common interests and purpose,
                                                             like a common mission. The cloud infrastructure is
                                                             shared by several organizations and supports a specific
                                                             community that has shared concerns. Government
                                                             departments, universities, central banks etc. often find
                                                             this type of cloud useful. According to NIST, the
                                                             community cloud refers to a cloud infrastructure shared
                                                             by several organizations within a specific community. It
                                                             may be managed by any one of the organizations or a
                                                             third party. A typical example is the Open Cirrus Cloud
                                                             Computing Testbed, which is a collection of Federated
              Figure 2: Service Model [12]                   data centers across six sites spanning from North
                                                             America to Asia. [16]

3. CLOUD COMPUTING DEPLOYMENT MODELS
Enterprises can choose to deploy applications on Public,
Private or Hybrid clouds. Cloud Integrators can play a
vital part in determining the right cloud path for each
organization.
3.1 Public Cloud
In a public cloud, the services and infrastructure are
provided off-site over the Internet. In this model, all of
the physical resources are owned and operated by a third
party cloud computing provider. The provider services
multiple clients that may consist of individuals or
corporations utilizing these resources through the public                Figure 3: Deployment Model [17]

Volume 1, Issue 4 November - December 2012                                                                    Page 112
   International Journal of Emerging Trends & Technology in Computer Science (IJETTCS)
       Web Site: www.ijettcs.org Email: editor@ijettcs.org, editorijettcs@gmail.com
Volume 1, Issue 4, November – December 2012                                    ISSN 2278-6856


4. CHALLENGES OF CLOUD COMPUTING                              The cloud providers have to make sure that the personal
                                                              information in not being share by any other person or
4.1 Reliability and liability
                                                              third party companies.
Users will expect the cloud to be a reliable resource
especially if a cloud provider takes over the task of
                                                              Data Integrity
running “mission-critical” applications and will expect
                                                              When data is on the cloud anyone can use them Cloud
clear delineation of liability if serious problems occur.
                                                              does not differentiate between sensitive data and common
Privacy and reliability are to be maintained during
                                                              data thus enabling anyone to access those sensitive data.
transportation and storage of the data.
                                                              It leads to lack of data integrity in cloud.
4.2 Data Security and privacy
Cloud is made for sharing the workload into the common
                                                              Data Theft
infrastructure and users have to rely on the cloud provider
                                                              Most of the cloud providers try to lease a server from
about their identity information, operation histories and
                                                              other service providers because it reduces cost and makes
perceptive data. Potential adopters are concerned about
                                                              operations more flexible. There is a high chance that the
the security of data outside the corporate firewall. A
                                                              data stored in their servers can be stolen by a malicious
related issue has to do with offshore data housing, which
                                                              user.
can pose problems of legislative compliance when data
crosses borders. In the short term, most companies can
                                                              Data loss
avoid these issues by using domestic cloud facilities. [18]
                                                              If the cloud provider shuts down due to some problems
4.3 Manageability
                                                              there will be a loss of data for the customers. The
Many startups have recognized the need for management
                                                              customers won’t be able to access those data because all
early on and have built management capabilities on top of
                                                              data will lose due to some system problems.
the existing cloud infrastructure/platforms. RightScale is
one of the early pioneers in this space. Their solution
                                                              Data location
solves many of the management issues such as auto-
                                                              The customer don’t know where his own data is located.
scaling and load balancing. [19]
                                                              The Cloud provider does not reveal all the information
                                                              about where the data are stored. The Data’s won’t even be
5. FUTURE OF CLOUD COMPUTING                                  in the same country of the Customer, it might be located
Cloud computing has become the standard operating             anywhere in the world.
procedure for any company looking at building or
deploying software today. The future of cloud computing       Deletion of Data
is in explosion of data and helping companies navigates       There are possibilities that the data which is no longer
the multitude of options in deploying traditional             needed is deleted by the user but is still there somewhere
application to the cloud. So far, most cloud systems have     in the cloud. It is a serious problem in the cloud about the
focused on hosting applications and data on remote            deletion. Customers make sure that data deleted from the
computers, employing in particular replication strategies     cloud is no longer kept. The cloud providers must make
to ensure availability and thus achieving a load balancing    sure that the data which the customer deletes is
scalability. However, the conceptual model of clouds          completely removed from the cloud.
exceeds such a simple technical approach and leads to
challenges not unlike the ones of the future internet, yet
with slightly different focus due to the combination of       7. CONCLUSION
concepts and goals implicit to cloud systems. [20] There
is a concern about cyber gangs hacking into commercial        Cloud computing is gaining popularity as a way to
and military systems, which leads to a worldwide trend        virtualized the datacenter and increase flexibility in the
that temporarily reduces public cloud adoption [21] and       use of computation resources. While the main reasons for
in order to protect against these negative trends security    adopting services based on cloud computing are cost
and standards must not be ignored.                            saving, flexibility and start-up speed, there are still doubts
                                                              about the security guarantees and the portability and
                                                              integration options offered by this model of services.
6. SECURITY            RISKS          IN        CLOUD         Cloud computing provides companies with new options
COMPUTING                                                     for managing infrastructures and new business models.
There are many security concerns that has to be               Its security deficiencies and benefits need to be carefully
considered while using cloud computing.                       weighed before making a decision to implement it. The
                                                              future of cloud computing is not definite but by analyzing
Confidentiality                                               the trends it seems that cloud technology will play a large
The Cloud providers sometimes hire third party                part in our day to day lives. In the future business and
companies to store data and information of their              consumers will benefit from higher interoperability
customers. The third party can use the data and expose it.

Volume 1, Issue 4 November - December 2012                                                                      Page 113
   International Journal of Emerging Trends & Technology in Computer Science (IJETTCS)
       Web Site: www.ijettcs.org Email: editor@ijettcs.org, editorijettcs@gmail.com
Volume 1, Issue 4, November – December 2012                                    ISSN 2278-6856


between clouds and maybe even a cloud network which
will improve sharing of resources and information.

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Volume 1, Issue 4 November - December 2012                                          Page 114

				
DOCUMENT INFO
Description: International Journal of Emerging Trends & Technology in Computer Science (IJETTCS) Web Site: www.ijettcs.org Email: editor@ijettcs.org, editorijettcs@gmail.com Volume 1, Issue 4, November – December 2012, ISSN 2278-6856, Impact Factor of IJETTCS for year 2012: 2.524