About the Author..............................................................................11
1. What is Cloud Computing?
Cloud computing refers to the delivery of computing resources over the Internet.
So instead of keeping the data on our own hard drive or updating applications as
our needs, we use a service over the Internet, at another location, to store our
information or use the applications hosted by it.
It allows individuals and businesses to use software and hardware that are
managed by third parties at remote locations. The cloud computing model allows
access to information and computer resources from anywhere that a network
connection is available. It provides a shared pool of resources, including data
storage space, networks, computer processing power, and specialized corporate
and user applications.
2. How does Cloud Computing get its name?
Cloud computing gets its name as a metaphor for the internet. Typically the
internet is represented in network diagrams as a cloud. The cloud icon represents
“all that other stuff” that makes the network work. It’s kind of like “etc.” for the
rest of the solution map.
3. Examples of Cloud Services
Some of the famous cloud services include:
Google: Has a private cloud that it uses for delivering many different
services to its users, including:
Gmail - Email access
Google Docs – Editing and storing documents
Google Translate – Text translations
Google Maps – maps
Picasa - photo uploading and sharing
and many more...
Apple iCloud: Some of the services includes like Mail, Contacts, Calendar,
Find My iPhone, Find my friends and iWork. Moreover "iTunes in the Cloud"
is a service which stores all your music, movies, apps and other iTunes
purchases on the Cloud so any Apple device can get them already.
Windows Live Sky drive: Microsoft joins the Cloud Computing party with
Windows Live SkyDrive. With SkyDrive you can store up to 25 GB of your
files for free. SkyDrive also enables you to create and edit your MS Office
documents with the same simplicity as MS Office desktop version.
Dropbox: Dropbox was one of the first services to provide online storage.
Today its one of the most popular service for storing your files on the
cloud. Dropbox has a client application for almost all the platforms
including Windows, Mac, iOS, Android, etc. The desktop version of
Dropbox syncs your local files and the files stored on the Dropbox cloud.
So that if you put a file in the local Dropbox folder, it will be automatically
synced with the cloud version.
Amazon: Amazon was one of the first companies to take cloud computing
initiatives and now has many cloud services for all, like Amazon Cloud
Player - stores all your music online and allows you to play or download it
from anywhere. Besides that you can also store documents, photos etc.
4. Characteristics of Cloud Computing
Cloud computing has a variety of characteristics, with the main ones being:
Shared Infrastructure: Uses a virtualized software model, enabling the
sharing of physical services, storage, and networking capabilities. The
cloud infrastructure, regardless of deployment model, seeks to make the
most of the available infrastructure across a number of users.
Dynamic Provisioning: Allows for the provision of services based on
current demand requirements. This is done automatically using software
automation, enabling the expansion and contraction of service capability,
as needed. This dynamic scaling needs to be done while maintaining high
levels of reliability and security.
Network Access: Needs to be accessed across the internet from a broad
range of devices such as PCs, laptops, and mobile devices, using
standards-based APIs (for example, ones based on HTTP). Deployments of
services in the cloud include everything from using business applications
to the latest application on the newest smartphones.
Managed Metering: Uses metering for managing and optimizing the
service and to provide reporting and billing information. In this way,
consumers are billed for services according to how much they have
actually used during the billing period. In short, cloud computing allows for
the sharing and scalable deployment of services, as needed, from almost
any location, and for which the customer can be billed based on actual
5. Service Models
Once a cloud is established, how its cloud computing services are deployed in
terms of business models can differ depending on requirements. The primary
service models being deployed are commonly known as:
Software as a Service (SaaS): A business model in which the software
and the associate data are centrally hosted on the cloud and the users
access the same through thin client via a web browser or may be some
desktop application. It is also sometimes known as “on-demand software”.
Example: SalesForce.com CRM, Microsoft Office 365, Wipro w-SaaS
Wipro w-SaaS: A platform for rapid software-as-a-service (SaaS)
enablement of business applications using Oracle Grid Computing and
Oracle application grid middleware for independent software vendors
(ISVs). The platform helps ISVs in enabling their 'existing' business
applications to operate in SaaS model in a non-intrusive manner with
minimal re-implementation, and enable the traditional single tenant
application to operate in an efficient multi-tenant mode.
Platform as a Service (PaaS): Consumers purchase access to the
platforms, enabling them to deploy their own software and applications in
the cloud. The operating systems and network access are not managed by
the consumer, and there might be constraints as to which applications can
Example: Google AppEngine, Microsoft Azure
Infrastructure as a Service (IaaS): Consumers control and manage the
systems in terms of the operating systems, applications, storage, and
network connectivity, but do not themselves control the cloud
infrastructure. Also known are the various subsets of these models that
may be related to a particular industry or market.
Example: Amazon EC2, Google Compute Engine
Storage as a Service (STaaS): A business model in which a large
service provider rents space in their storage infrastructure on a
subscription basis. The economy of scale in the service provider's
infrastructure allows them to provide storage much more cost effectively
than most individuals or corporations can provide their own storage, when
total cost of ownership is considered.
Example: Dropbox, Windows Sky Drive
Security as a Service (SECaaS): A business model in which a large
service provider integrates their security services into a corporate
infrastructure on a subscription basis more cost effectively than most
individuals or corporations can provide on their own, when total cost of
ownership is considered. These security services often include
authentication, anti-virus, anti-malware/spyware, intrusion detection, and
security event management, among others.
Example: Zscaler, Seculert
6. Deployment Models
Deploying cloud computing can differ depending on requirements, and the
following four deployment models have been identified, each with specific
characteristics that support the needs of the services and users of the clouds in
Private Cloud: 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.
Community Cloud: 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.
Public Cloud: 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.
Hybrid Cloud: 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 cloud.
The following are some of the possible benefits for those who offer cloud
computing-based services and applications:
Cost Savings: 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.
Scalability/Flexibility: 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
Reliability: Services using multiple redundant sites can support business
continuity and disaster recovery.
Maintenance: 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 Accessible: Mobile workers have increased productivity due to
systems accessible in an infrastructure available from anywhere.
Companies are increasingly aware of the business value that cloud computing
brings and are taking steps towards transition to the cloud. A smooth transition
entails a thorough understanding of the benefits as well as challenges involved.
Like any new technology, the adoption of cloud computing is not free from issues.
Some of the most important challenges are as follows:
Security and Privacy: The main challenge to cloud computing is how it
addresses the security and privacy concerns of businesses thinking of
adopting it. The fact that the valuable enterprise data will reside outside
the corporate firewall raises serious concerns. Hacking and various attacks
to cloud infrastructure would affect multiple clients even if only one site is
attacked. These risks can be mitigated by using security applications,
encrypted file systems, data loss software, and buying security hardware
to track unusual behavior across servers.
Service Delivery and Billing: It is difficult to assess the costs involved
due to the on-demand nature of the services. Budgeting and assessment
of the cost will be very difficult unless the provider has some good and
comparable benchmarks to offer. The service-level agreements (SLAs) of
the provider are not adequate to guarantee the availability and scalability.
Businesses will be reluctant to switch to cloud without a strong service
Interoperability and Portability: Businesses should have the leverage
of migrating in and out of the cloud and switching providers whenever they
want, and there should be no lock-in period. Cloud computing services
should have the capability to integrate smoothly with the on-premise IT.
Reliability and Availability: Cloud providers still lack round-the-clock
service; this results in frequent outages. It is important to monitor the
service being provided using internal or third-party tools. It is vital to have
plans to supervise usage, SLAs, performance, robustness, and business
dependency of these services.
Performance and Bandwidth Cost: Businesses can save money on
hardware but they have to spend more for the bandwidth. This can be a
low cost for smaller applications but can be significantly high for the dataintensive applications. Delivering intensive and complex data over the
network requires sufficient bandwidth.
All these challenges should not be considered as road blocks in the pursuit of
cloud computing. It is rather important to give serious consideration to these
issues and the possible ways out before adopting the technology.
Cloud computing is still struggling in its infancy, with positive and negative
comments made on its possible implementation for a large-sized enterprise. IT
technicians are spearheading the challenge, while academia is bit slower to react.
Several groups have recently been formed, such as the Cloud Security Alliance or
the Open Cloud Consortium, with the goal of exploring the possibilities offered by
cloud computing and to establish a common language among different providers.
In this boiling pot, cloud computing is facing several issues in gaining recognition
for its merits. Its security deficiencies and benefits need to be carefully weighed
before making a decision to implement it. However, the future looks less cloudy
as far as more people being attracted by the topic and pursuing research to
improve on its drawbacks.
Security-as-a-Service: Using the Cloud to Deliver Security:
11. About the Author
Amit Sarawgi is ISTQB Advance Level Certified Test Analyst, with 3+ years of
testing experience in different types of testing like SOA, End-to-End, OAT
(Operations Acceptance Testing). He holds a Bachelor's degree in ‘Computer
Science and Communication’ from Laxmi Niwas Mittal Institute of Information