Cloud Computing & Virtualization in Cloud

UNIT -1
Introduction to Cloud Computing
Cloud Computing is the delivery of computing services such as servers, storage, databases, networking, software,
analytics, intelligence, and more, over the Cloud (Internet).
Cloud Computing provides an alternative to the on-premises datacentre. With an on-premises datacentre, we have
to manage everything, such as purchasing and installing hardware, virtualization, installing the operating system, and
any other required applications, setting up the network, configuring the firewall, and setting up storage for data.
After doing all the set-up, we become responsible for maintaining it through its entire lifecycle.
But if we choose Cloud Computing, a cloud vendor is responsible for the hardware purchase and maintenance. They
also provide a wide variety of software and platform as a service. We can take any required services on rent. The
cloud computing services will be charged based on usage.
The cloud environment provides an easily accessible online portal that makes handy for the user to manage the
compute, storage, network, and application resources. Some cloud service providers are in the following figure.

Advantages of cloud computing
o Cost: It reduces the huge capital costs of buying hardware and software.
o Speed: Resources can be accessed in minutes, typically within a few clicks.
o Scalability: We can increase or decrease the requirement of resources according to the business
requirements.
o Productivity: While using cloud computing, we put less operational effort. We do not need to apply patching,
as well as no need to maintain hardware and software. So, in this way, the IT team can be more productive
and focus on achieving business goals.
o Reliability: Backup and recovery of data are less expensive and very fast for business continuity.
o Security: Many cloud vendors offer a broad set of policies, technologies, and controls that strengthen our
data security.
Types of Cloud Computing
o Public Cloud: The cloud resources that are owned and operated by a third-party cloud service provider are
termed as public clouds. It delivers computing resources such as servers, software, and storage over the
internet
o Private Cloud: The cloud computing resources that are exclusively used inside a single business or
organization are termed as a private cloud. A private cloud may physically be located on the company’s on-
site datacentre or hosted by a third-party service provider.

o Hybrid Cloud: It is the combination of public and private clouds, which is bounded together by technology
that allows data applications to be shared between them. Hybrid cloud provides flexibility and more
deployment options to the business.
Types of Cloud Services
1. Infrastructure as a Service (IaaS): In IaaS, we can rent IT infrastructures like servers and virtual machines
(VMs), storage, networks, operating systems from a cloud service vendor. We can create VM running
Windows or Linux and install anything we want on it. Using IaaS, we don’t need to care about the hardware
or virtualization software, but other than that, we do have to manage everything else. Using IaaS, we get
maximum flexibility, but still, we need to put more effort into maintenance.
2. Platform as a Service (PaaS): This service provides an on-demand environment for developing, testing,
delivering, and managing software applications. The developer is responsible for the application, and the
PaaS vendor provides the ability to deploy and run it. Using PaaS, the flexibility gets reduce, but the
management of the environment is taken care of by the cloud vendors.
3. Software as a Service (SaaS): It provides a centrally hosted and managed software services to the endusers.
It delivers software over the internet, on-demand, and typically on a subscription basis. E.g., Microsoft One
Drive, Dropbox, WordPress, Office 365, and Amazon Kindle. SaaS is used to minimize the operational cost to
themaximum extent.

Vision Of Cloud Computing
1. Cloud computing provides the facility to provision virtual hardware, runtime environment and services to a
person having money.
2. These all things can be used as long as they are needed by the user.
3. The whole collection of computing system is transformed into collection of utilities, which can be provisioned
and composed together to deploy systems in hours rather than days, with no maintenance cost.
4. The long term vision of a cloud computing is that IT services are traded as utilities in an open market without
technological and legal barriers.
5. In the future, we can imagine that it will be possible to find the solution that matches with our requirements
by simply entering out request in a global digital market that trades with cloud computing services.
6. The existence of such market will enable the automation of discovery process and its integration into its
existing software systems.
7. Due to the existence of a global platform for trading cloud services will also help service providers to
potentially increase their revenue.
8. A cloud provider can also become a consumer of a competition service in order to fulfill its promises to
customers.
9. In the near future we can imagine a solution that suits our needs by simply applying our application to the
global digital market for cloud computing services.
10. The presence of this market will enable the acquisition process to automatically integrate with its integration
into its existing software applications. The availability of a global cloud trading platform will also help service
providers to increase their revenue.
11. A cloud provider can also be a buyer of a competitive service to fulfill its promises to customers.
Defining A Cloud
The term cloud refers to a network or the internet. It is a technology that uses remote servers on the internet to
store, manage, and access data online rather than local drives. The data can be anything such as files, images,
documents, audio, video, and more.
There are the following operations that we can do using cloud computing:
o Developing new applications and services
o Storage, back up, and recovery of data
o Hosting blogs and websites
o Delivery of software on demand
o Analysis of data
o Streaming videos and audios

Why Cloud Computing?
Small as well as large IT companies, follow the traditional methods to provide the IT infrastructure. That means for
any IT company, we need a Server Room that is the basic need of IT companies.
In that server room, there should be a database server, mail server, networking, firewalls, routers, modem, switches,
QPS (Query Per Second means how much queries or load will be handled by the server), configurable system, high
net speed, and the maintenance engineers.
To establish such IT infrastructure, we need to spend lots of money. To overcome all these problems and to reduce
the IT infrastructure cost, Cloud Computing comes into existence.
Cloud Computing Reference Model / Service Model
There are the following three types of cloud service models -
1. Infrastructure as a Service (IaaS)
2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)

Fig. Cloud Reference Modal
Infrastructure as a Service (IaaS)
IaaS is also known as Hardware as a Service (HaaS). It is a computing infrastructure managed over the internet. The
main advantage of using IaaS is that it helps users to avoid the cost and complexity of purchasing and managing the
physical servers.
IaaS provider provides the following services -
1. Compute: Computing as a Service includes virtual central processing units and virtual main memory
for the Vms that is provisioned to the endusers.
2. Storage: IaaS provider provides back-end storage for storing files.
3. Network: Network as a Service (NaaS) provides networking components such as routers, switches,
and bridges for the Vms.
4. Load balancers: It provides load balancing capability at the infrastructure layer.

Characteristics of IaaS
o Resources are available as a service
o Services are highly scalable
o Dynamic and flexible
o GUI and API-based access
o Automated administrative tasks
Example: DigitalOcean, Linode, Amazon Web Services (AWS), Microsoft Azure, Google Compute Engine (GCE),
Rackspace, and Cisco Metacloud.
Platform as a Service (PaaS)
PaaS cloud computing platform is created for the programmer to develop, test, run, and manage the applications.
PaaS providers provide the Programming languages, Application frameworks, Databases, and Other tools:
1. Programming languages
PaaS providers provide various programming languages for the developers to develop the applications.
Some popular programming languages provided by PaaS providers are Java, PHP, Ruby, Perl, and Go.
2. Application frameworks
PaaS providers provide application frameworks to easily understand the application development. Some
popular application frameworks provided by PaaS providers are Node.js, Drupal, Joomla, WordPress, Spring,
Play, Rack, and Zend.
3. Databases
PaaS providers provide various databases such as ClearDB, PostgreSQL, MongoDB, and Redis to
communicate with the applications.

4. Other tools
PaaS providers provide various other tools that are required to develop, test, and deploy the applications.
Characteristics of PaaS
o Accessible to various users via the same development application.
o Integrates with web services and databases.
o Builds on virtualization technology, so resources can easily be scaled up or down as per the organization's
need.
o Support multiple languages and frameworks.
o Provides an ability to "Auto-scale".
Example: AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, Magento
Commerce Cloud, and OpenShift.
Software as a Service (SaaS)
SaaS is also known as "on-demand software". It is a software in which the applications are hosted by a cloud service
provider. Users can access these applications with the help of internet connection and web browser.
There are the following services provided by SaaS providers -
Business Services - SaaS Provider provides various business services to start-up the business. The SaaS
business services include ERP (Enterprise Resource Planning), CRM (Customer Relationship
Management), billing, and sales.
Document Management - SaaS document management is a software application offered by a third party
(SaaS providers) to create, manage, and track electronic documents.
Example: Slack, Samepage, Box, and Zoho Forms.
Social Networks - As we all know, social networking sites are used by the general public, so social
networking service providers use SaaS for their convenience and handle the general public's information.
Mail Services - To handle the unpredictable number of users and load on e-mail services, many e-mail
providers offering their services using SaaS.

Characteristics of SaaS
o Managed from a central location
o Hosted on a remote server
o Accessible over the internet
o Users are not responsible for hardware and software updates. Updates are applied automatically.
o The services are purchased on the pay-as-per-use basis
o Example: BigCommerce, Google Apps, Salesforce, Dropbox, ZenDesk, Cisco WebEx, ZenDesk, Slack, and
GoToMeeting.
Difference between IaaS, PaaS, and SaaS
The below table shows the difference between IaaS, PaaS, and SaaS -
IaaS Paas SaaS
It provides a virtual data center to store
information and create platforms for
app development, testing, and
deployment.
It provides virtual platforms and
tools to create, test, and deploy
apps.
It provides web software and
apps to complete business tasks.
It provides access to resources such as
virtual machines, virtual storage, etc.
It provides runtime environments
and deployment tools for
applications.
It provides software as a service
to the end-users.
It is used by network architects. It is used by developers. It is used by end users.
IaaS provides
only
Infrastructure.
PaaS provides
Infrastructure+Platform.
SaaS provides
Infrastructure+Platform
+Software.
Characteristics And Benefits
The characteristics of cloud computing are given below:
1) Agility
The cloud works in a distributed computing environment. It shares resources among users and works very fast.

2) High availability and reliability
The availability of servers is high and more reliable because the chances of infrastructure failure are minimum.
3) High Scalability
Cloud offers "on-demand" provisioning of resources on a large scale, without having engineers for peak loads.
4) Multi-Sharing
With the help of cloud computing, multiple users and applications can work more efficiently with cost reductions
by sharing common infrastructure.
5) Device and Location Independence
Cloud computing enables the users to access systems using a web browser regardless of their location or what device
they use e.g. PC, mobile phone, etc. As infrastructure is off-site (typically provided by a thirdparty) and accessed via
the Internet, users can connect from anywhere.
6) Maintenance
Maintenance of cloud computing applications is easier, since they do not need to be installed on each user's
computer and can be accessed from different places. So, it reduces the cost also.
7) Low Cost
By using cloud computing, the cost will be reduced because to take the services of cloud computing, IT Company
need not to set its own infrastructure and pay-as-per usage of resources.
8) Services in the pay-per-use mode
Application Programming Interfaces (APIs) are provided to the users so that they can access services on the cloud
by using these APIs and pay the charges as per the usage of services.
Benefits
• Accessibility anywhere, with any device. ...
• Ability to get rid of most or all hardware and software. ...
• Centralized data security. ...
• Higher performance and availability. ...
• Quick application deployment. ...
• Instant business insights. ...
• Business continuity. ...
• Price-performance and cost savings
Challenges Ahead
Cloud computing, an emergent technology, has placed many challenges in different aspects of data and information
handling. Some of these are shown in the following diagram:

1. Data Security and Privacy
2. cost management
3. multi cloud environments
4. performance challenges
5. interoperability and flexibility
6. high dependence on Network
7. Lack of knowledge and Expertise
8. Data loss is the most common cloud security risks of cloud computing. It is also known as data leakage. Data
loss is the process in which data is being deleted, corrupted, and unreadable by a user, software, or
application.
Security and Privacy
Security and Privacy of information is the biggest challenge to cloud computing. Security and privacy issues can be
overcome by employing encryption, security hardware and security applications.
Portability
This is another challenge to cloud computing that applications should easily be migrated from one cloud provider to
another. There must not be vendor lock-in. However, it is not yet made possible because each of the cloud provider
uses different standard languages for their platforms.
Interoperability
It means the application on one platform should be able to incorporate services from the other platforms. It is made
possible via web services, but developing such web services is very complex.
Computing Performance
Data intensive applications on cloud requires high network bandwidth, which results in high cost. Low bandwidth
does not meet the desired computing performance of cloud application.
Reliability and Availability

It is necessary for cloud systems to be reliable and robust because most of the businesses are now becoming
dependent on services provided by third-party.
Historical Developments
Before emerging the cloud computing, there was Client/Server computing which is basically a centralized storage in
which all the software applications, all the data and all the controls are resided on the server side.
If a single user wants to access specific data or run a program, he/she need to connect to the server and then gain
appropriate access, and then he/she can do his/her business.
Then after, distributed computing came into picture, where all the computers are networked together and share
their resources when needed.
On the basis of above computing, there was emerged of cloud computing concepts that later implemented.
At around in 1961, John MacCharty suggested in a speech at MIT that computing can be sold like a utility, just like a
water or electricity. It was a brilliant idea, but like all brilliant ideas, it was ahead if its time, as for the next few
decades, despite interest in the model, the technology simply was not ready for it.
But of course time has passed and the technology caught that idea and after few years we mentioned that:
In 1999, Salesforce.com started delivering of applications to users using a simple website. The applications were
delivered to enterprises over the Internet, and this way the dream of computing sold as utility were true.
In 2002, Amazon started Amazon Web Services, providing services like storage, computation and even human
intelligence. However, only starting with the launch of the Elastic Compute Cloud in 2006 a truly commercial service
open to everybody existed.
In 2009, Google Apps also started to provide cloud computing enterprise applications.
Of course, all the big players are present in the cloud computing evolution, some were earlier, some were later. In
2009, Microsoft launched Windows Azure, and companies like Oracle and HP have all joined the game. This proves
that today, cloud computing has become mainstream.

Risks And Approaches of Migration Into Cloud
Cloud migration is the procedure of transferring applications, data, and other types of business
components to any cloud computing platform. There are several parts of cloud migration an organization
can perform. The most used model is the applications and data transfer through an on-premises and local
data center to any public cloud.
But, a cloud migration can also entail transferring applications and data from a single cloud environment or
facilitate them to another- a model called cloud-to-cloud migration. The other type of cloud migration is
reverse cloud migration, cloud exit, and cloud repatriation where applications or data are transferred and
back to the local data center.
#1.Not having a cloud migration strategy
One of the biggest risks of cloud migration is attempting to make the move without a clear, detailed cloud migration
strategy. When making the move to the cloud, an organization must make several important decisions, including:
• IT Asset Distribution: Different data and applications are best suited to being hosted on-prem or in public or
private cloud environments. Most organizations select a hybrid cloud model and distribute their assets across
private and public clouds and on-site infrastructure. A cloud migration strategy should include a breakdown
of the assets that should be hosted in each environment.
• Cloud Platform(s) to Use: Several cloud providers exist and each offers many different options, all of which
are designed and optimized for different purposes. Before making the move to the cloud, an organization
should identify the platform(s) best suited to its use cases.
• Application Deployment Model: The cloud provides new application deployment options, such as serverless
applications and containers. When preparing to migrate to the cloud, an organization needs to decide
whether it will “lift and shift” applications designed for on-prem environments to the cloud or re-architect
applications to take full advantage of the benefits of the cloud.
Not making these and other important decisions in advance can increase the cost, duration, and complexity of a
cloud migration process. Also, making the wrong decisions can create significant security risks, such as storing or
processing sensitive information in a public cloud environment.
#2. Complex existing architecture
In an on-prem environment, complex architectures are workable. Intra-site network latency is relatively low, so an
organization can support a complex array of databases and applications without significant performance impacts.
When moving to the cloud, a complex existing infrastructure can put the success of the cloud migration at risk. Some
of the potential impacts include:
• Extended Migration Process: If an organization’s on-prem architecture is complex, developing and
implementing a migration strategy will be a complex process. Organizations will have to develop a strategy
for migrating their IT resources to the cloud without negatively impacting performance or security.
• Reduced Performance: If an organization’s infrastructure is distributed between on-prem architecture and
multiple cloud environments, then latency is much higher than in an on-prem environment. As a result,
complex architectures with significant interconnectivity between assets hosted in different locations will
suffer degraded performance when moving to the cloud.

Cloud infrastructure offers new architectural options, such as serverless applications. If an organization has a complex
architecture, cloud migration provides an opportunity to re-design and re-architect an organization’s complex
infrastructure.
#3. Selecting the wrong cloud service provider (CSP)
Different CSPs have offerings with different features and strengths. For example, organizations looking for a general-
purpose cloud might choose AWS, those that use LDAP and Active Directory may benefit from Azure’s built-in
integration with these systems, Oracle Cloud specializes in databases and data management, and Google Cloud
Platform (GCP) has strong data analytics capabilities.
The “right” cloud for an organization depends on its unique use cases. If an organization chooses a CSP that does not
align with its intended uses, then it might not be able to extract the full value from its cloud migration and may face
significant performance issues or a complex migration while trying to implement its required functionality in a non-
ideal environment. Trying to fix these issues by migrating from one CSP to another can result in additional expenses
and overhead.
When planning a cloud migration, an organization should thoroughly research the available options and ensure that
their chosen cloud provider implements their required functionality and can support any necessary third-party
solutions. Many organizations choose a multi-cloud infrastructure that provides optimal environments for various
resources and use cases.
#4. Long Migration Process
Many organizations’ IT environments have grown up over several years within an on-prem environment. Applications
and infrastructure designed for on-prem deployment do not always translate well to a cloud environment.
As a result, an organization’s cloud migration process may be extended as it works to re-architect systems and
applications for cloud environments. In general, a cloud migration can take a year or more.
Some impacts of an extended cloud migration include:
• Productivity Losses: As companies move through the cloud migration process, their IT infrastructure will pass
through intermediate states as some resources are migrated to the cloud while others are still waiting for
their turns. Since these intermediate states are unlikely to be optimized, an organization can suffer significant
losses to performance and productivity that can hurt it and its customers.
• Security Risks: In addition to potential productivity impacts, an organization’s move through intermediate
states of cloud migration may carry security risks as well. If security policies and solutions are not updated in
sync with cloud migration, corporate data and applications may be exposed to attack.
• Resource Utilization: Cloud migration consumes a great deal of time and other resources. An inefficient cloud
migration strategy may waste resources, increasing the cost to the business.
An extended migration process can hurt an organization and its customers. Before beginning the migration, a
company should carefully consider its migration strategy and attempt to optimize performance and security
throughout the entire migration process.
#5. Data Breach
Throughout the cloud migration process, an organization must ensure that data and applications are secure. While
a company may have a pre-migration and post-migration security strategy, this is not enough to protect its resources.

The organization will transition through numerous intermediate states as data and applications move to the cloud.
If an organization’s security strategy does not adapt to provide adequate protection at each of these intermediate
steps, then attackers may be able to steal data or exploit applications while the organization is in a vulnerable state.
A corporate cloud migration strategy must incorporate a migration security strategy. This includes plans for ensuring
that corporate data and applications are appropriately protected at every stage of the migration process.
#6. Unexpected cloud costs or monthly sticker-shock
Making the move to the cloud can dramatically decrease an organization’s infrastructure costs. By outsourcing the
management of an organization’s underlying infrastructure to a third-party provider, an organization can take
advantage of the cost savings of its CSP’s optimizations and economy of scale.
However, an organization can only take full advantage of the cost savings of the cloud if its IT infrastructure is
designed for the cloud. If an organization “lifts and shifts” legacy applications to cloud environments or purchases
oversized service packages, then the cost of the cloud may exceed the cost of hosting the same infrastructure on-
premises.
Additionally, “as a service” infrastructure means that an organization pays for what it uses. It is often difficult and
complicated to monitor ongoing cloud costs, so cloud costs often spiral out of expectation, until the monthly bill
arrives.
Cloud migration can be a tradeoff between short-term costs and long-term benefits. Designing and optimizing
architecture and applications for cloud environments can reduce overhead and costs in the long term.
Types of Cloud
There are the following 4 types of cloud that you can deploy according to the organization's needs-
o Public Cloud o Private Cloud o Hybrid Cloud o Community Cloud
1 .Public Cloud
Public cloud is open to all to store and access information via the Internet using the pay-per-usage method.
In public cloud, computing resources are managed and operated by the Cloud Service Provider ( CSP ).
Example: Amazon elastic compute cloud (EC2), IBM SmartCloud Enterprise, Microsoft, Google App

Engine, Windows Azure Services Platform.y Video
Advantages of Public Cloud
There are the following advantages of Public Cloud -
o Public cloud is owned at a lower cost than the private and hybrid cloud.
o Public cloud is maintained by the cloud service provider, so do not need to worry about the
maintenance.
o Public cloud is easier to integrate. Hence it offers a better flexibility approach to consumers.
o Public cloud is location independent because its services are delivered through the internet.
o Public cloud is highly scalable as per the requirement of computing resources.
o It is accessible by the general public, so there is no limit to the number of users.
Disadvantages of Public Cloud
o Public Cloud is less secure because resources are shared publicly.
o Performance depends upon the high-speed internet network link to the cloud provider.
o The Client has no control of data.
2 .Private Cloud
Private cloud is also known as an internal cloud or corporate cloud. It is used by organizations to build
and manage their own data centers internally or by the third party. It can be deployed using Opensource
tools such as Openstack and Eucalyptus.
Based on the location and management, National Institute of Standards and Technology (NIST) divide
private cloud into the following two parts-
o On-premise private cloud
o Outsourced private cloud

Advantages of Private Cloud
There are the following advantages of the Private Cloud -
o Private cloud provides a high level of security and privacy to the users.
o Private cloud offers better performance with improved speed and space capacity.
o It allows the IT team to quickly allocate and deliver on-demand IT resources.
o The organization has full control over the cloud because it is managed by the organization itself. So,
there is no need for the organization to depends on anybody.
o It is suitable for organizations that require a separate cloud for their personal use and data security
is the first priority.
Disadvantages of Private Cloud
o Skilled people are required to manage and operate cloud services.
o Private cloud is accessible within the organization, so the area of operations is limited.
o Private cloud is not suitable for organizations that have a high user base, and organizations that do
not have the prebuilt infrastructure, sufficient manpower to maintain and manage the cloud.
3 .Hybrid Cloud
Hybrid Cloud is a combination of the public cloud and the private cloud. we can say:
Hybrid Cloud = Public Cloud + Private Cloud
Hybrid cloud is partially secure because the services which are running on the public cloud can be accessed
by anyone, while the services which are running on a private cloud can be accessed only by the
organization's users.
Example: Google Application Suite (Gmail, Google Apps, and Google Drive), Office 365 (MS Office on the
Web and One Drive), Amazon Web Services.

Advantages of Hybrid Cloud
There are the following advantages of Hybrid Cloud -
o Hybrid cloud is suitable for organizations that require more security than the public cloud.
o Hybrid cloud helps you to deliver new products and services more quickly.
o Hybrid cloud provides an excellent way to reduce the risk.
o Hybrid cloud offers flexible resources because of the public cloud and secure resources because of
the private cloud.
Disadvantages of Hybrid Cloud
o In Hybrid Cloud, security feature is not as good as the private cloud.
o Managing a hybrid cloud is complex because it is difficult to manage more than one type of
deployment model.
o In the hybrid cloud, the reliability of the services depends on cloud service providers.
4 .Community Cloud
Community cloud allows systems and services to be accessible by a group of several organizations to share
the information between the organization and a specific community. It is owned, managed, and operated
by one or more organizations in the community, a third party, or a combination of them.
Example: Health Care community cloud

Advantages of Community Cloud
o Community cloud is cost-effective because the whole cloud is being shared by several organizations
or communities.
o Community cloud is suitable for organizations that want to have a collaborative cloud with more
security features than the public cloud.
o It provides better security than the public cloud.
o It provdes collaborative and distributive environment.
o Community cloud allows us to share cloud resources, infrastructure, and other capabilities among
various organizations.
Disadvantages of Community Cloud
• Community cloud is not a good choice for every organization.
• Security features are not as good as the private cloud.
• It is not suitable if there is no collaboration.
• The fixed amount of data storage and bandwidth is shared among all community members.
Difference between public cloud, private cloud, hybrid cloud, and community
cloud -
The below table shows the difference between public cloud, private cloud, hybrid cloud, and community
cloud.
Parameter
Public
Cloud
Private
Cloud
Hybrid Cloud Community Cloud
Host Service
provider Enterprise (Third
party)
Enterprise ( Third party
)
Community (Third
party)
Users
General public Selected users
Selected users Community members
Access Internet Internet,
VPN
Internet, VPN Internet, VPN
Owner Service
provider
Enterprise Enterprise Community

Cloud Computing & Virtualization in Cloud

Cloud Computing & Virtualization in Cloud

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