Cloud Computing - Lecture notes 10 PDF

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1 INTRODUCTION TO CLOUD COMPUTING(A) History of Cloud ComputingCloud computing is believed to have been invented by Joseph Carl RobnettLicklider in the 1960s with his work on ARPANET to connect people and data from anywhere at any timeWhat is Cloud?The term Cloud refers to a Network or Internet. In ...

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1.1 INTRODUCTION TO CLOUD COMPUTING (A) History of Cloud Computing Cloud computing is believed to have been invented by Joseph Carl RobnettLicklider in the 1960s with his work on ARPANET to connect people and data from anywhere at any time

What is Cloud? The term Cloud refers to a Network or Internet. In other words, we can say that Cloud is something, which is present at remote location. Cloud can provide services over public and private networks, i.e., WAN, LAN or VPN.

What is Cloud Computing? Cloud computing is a technology that uses the internet for storing and managing data on remote servers and then access data via the internet. ... One such example is Google cloud – It is a suite of public cloud services offered by Google. All the application development run on Google hardware.

Cloud computing offers platform independency, as the software is not required to be installed locally on the PC. Hence, the Cloud Computing is making our business applications mobile and collaborative. Top 10 Companies Using Cloud        

Netflix. Cloud provider: AWS. ...(amazon web service) Pinterest. Cloud provider: AWS. ... Coca-Cola. Cloud provider: AWS. ... Kroger. Cloud provider: Microsoft Azure. .(Microsoft's operating system for cloud computing...) Gameloft. Cloud provider: AWS. ... Etsy. Cloud provider: Google Cloud. ... eBay. Cloud provider: Google Cloud. ... Twitter (ad platform) Cloud provider: Google Cloud.

Cloud computing enables software and data to reside on vast numbers of servers connected over the Internet, rather than on servers at the physical location of an individual, company, or other organization

CLOUD COMPUTING-ARCHITECTURE The Cloud Computing architecture comprises of many cloud components, each of them are loosely coupled. We can broadly divide the cloud architecture into two parts:  Front End  Back End Each of the ends are connected through a network, usually via Internet. The following diagram shows the graphical view of cloud computing architecture:

Basic Concepts There are certain services and models working behind the scene making the cloud computing feasible and accessible to end users. Following are the working models for cloud computing:  

Deployment Models Service Models

Deployment Models (types) Deployment models define the type of access to the cloud, i.e., how the cloud is located? Cloud can have any of the four types of access: Public, Private, Hybrid, and Community.

Public Cloud The public cloud allows systems and services to be easily accessible to the general public. Public cloud may be less secure because of its openness. Private Cloud The private cloud allows systems and services to be accessible within an organization. It is more secured because of its private nature. Community Cloud The community cloud allows systems and services to be accessible by a group of organizations. Hybrid Cloud

The hybrid cloud is a mixture of public and private cloud, in which the critical activities are performed using private cloud while the non-critical activities are performed using public cloud.

Service Models (common forms) Cloud computing is based on service models. These are categorized into three basic service models which are  

Infrastructure-as–a-Service (IaaS) Platform-as-a-Service (PaaS)

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Software-as-a-Service (SaaS)

Anything-as-a-Service (XaaS) is yet another service model, which includes Network-as-a-Service, Business-as-a-Service, Identity-as-a-Service, Database-asa-Service or Strategy-as-a-Service. The Infrastructure-as-a-Service (IaaS) is the most basic level of service. Each of the service models inherit the security and management mechanism from the underlying model, as shown in the following diagram:

Infrastructure-as-a-Service (IaaS) IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage, etc. Platform-as-a-Service (PaaS) PaaS provides the runtime environment for applications, development and deployment tools, etc. Software-as-a-Service (SaaS)

SaaS model allows to use software applications as a service to end-users.

advantages Cloud Computing has numerous advantages. Some of them are listed below  One can access applications as utilities, over the Internet.  One can manipulate and configure the applications online at any time.  It does not require to install a software to access or manipulate cloud application.  Cloud Computing offers online development and deployment tools, programming runtime environment through PaaS model.  Cloud resources are available over the network in a manner that provide platform independent access to any type of clients.  Cloud Computing offers on-demand self-service. The resources can be used without interaction with cloud service provider.  Cloud Computing is highly cost effective because it operates at high efficiency with optimum utilization. It just requires an Internet connection  Cloud Computing offers load balancing that makes it more reliable.

disadvantages Although cloud Computing is a promising innovation with various benefits in the world of computing, it comes with risks. Some of them are discussed below:

Security and Privacy

It is the biggest concern about cloud computing. Since data management and infrastructure management in cloud is provided by third-party, it is always a risk to handover the sensitive information to cloud service providers. Although the cloud computing vendors ensure highly secured password protected accounts, any sign of security breach may result in loss of customers and businesses.

Lock In It is very difficult for the customers to switch from one Cloud Service Provider (CSP) to another. It results in dependency on a particular CSP for service.

Isolation Failure This risk involves the failure of isolation mechanism that separates storage, memory, and routing between the different tenants.

Management Interface Compromise In case of public cloud provider, the customer management interfaces are accessible through the Internet.

Insecure or Incomplete Data Deletion It is possible that the data requested for deletion may not get deleted. It happens because either of the following reasons  Extra copies of data are stored but are not available at the time of deletion  Disk that stores data of multiple tenants is destroyed.

Characteristics of Cloud Computing There are four key characteristics of cloud computing. They are shown in the following diagram:

On Demand Self Service Cloud Computing allows the users to use web services and resources on demand. One can logon to a website at any time and use them.

Broad Network Access Since cloud computing is completely web based, it can be accessed from anywhere and at any time.

Resource Pooling Cloud computing allows multiple tenants to share a pool of resources. One can share single physical instance of hardware, database and basic infrastructure.

Rapid Elasticity It is very easy to scale the resources vertically or horizontally at any time. Scaling of resources means the ability of resources to deal with increasing or decreasing demand. The resources being used by customers at any given point of time are automatically monitored.

(B) Evolution of Cloud Computing Cloud computing is all about renting computing services. This idea first came in the 1950s. In making cloud computing what it is today, five technologies played a vital role. These are distributed systems and its peripherals, virtualization, web 2.0, service orientation, and utility computing.

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Distributed Systems: It is a composition of multiple independent systems but all of them are depicted as a single entity to the users. The purpose of distributed systems is to share resources and also use them effectively and efficiently. Distributed systems possess characteristics such as scalability, concurrency, continuous availability, heterogeneity, and independence in failures. But the main problem with this system was that all the systems were required to be present at the same geographical location. Thus to solve this problem, distributed computing led to three more types of computing and they were-Mainframe computing, cluster computing, and grid computing.

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Mainframe computing: Mainframes which first came into existence in 1951 are highly powerful and reliable computing machines. These are responsible for handling large data such as massive input-output operations. Even today these are used for bulk processing tasks such as online transactions etc. These systems have almost no downtime with high fault tolerance. After distributed computing, these increased the processing capabilities of the system. But these were very expensive. To reduce this cost, cluster computing came as an alternative to mainframe technology.

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Cluster computing: In 1980s, cluster computing came as an alternative to mainframe computing. Each machine in the cluster was connected to each other by a network with high bandwidth. These were way cheaper than those mainframe systems. These were equally capable of high computations. Also, new nodes could easily be added to the cluster if it was required. Thus, the problem of the cost was solved to some extent but the problem related to geographical restrictions still pertained. To solve this, the concept of grid computing was introduced.

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Grid computing: In 1990s, the concept of grid computing was introduced. It means that different systems were placed at entirely different geographical locations and these all were connected via the internet. These systems belonged to different organizations and thus the grid consisted of heterogeneous nodes. Although it solved some problems but new problems emerged as the distance between the nodes increased. The main problem which was encountered was the low availability of high bandwidth connectivity and with it other network associated issues. Thus. cloud computing is often referred to as “Successor of grid computing”.

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Virtualization: It was introduced nearly 40 years back. It refers to the process of creating a virtual layer over the hardware which allows the user to run multiple instances simultaneously on the hardware. It is a key technology used in cloud computing. It is the base on which major cloud computing services such as Amazon EC2, VMware vCloud, etc work on. Hardware virtualization is still one of the most common types of virtualization.

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Web 2.0: It is the interface through which the cloud computing services interact with the clients. It is because of Web 2.0 that we have interactive and dynamic web pages. It also increases flexibility among web pages. Popular examples of web 2.0 include Google Maps, Facebook, Twitter, etc. Needless to say, social media is possible because of this technology only. In gained major popularity in 2004.

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Service orientation: It acts as a reference model for cloud computing. It supports low-cost, flexible, and evolvable applications. Two important concepts were introduced in this computing model. These were Quality of Service (QoS) which also includes the SLA (Service Level Agreement) and Software as a Service (SaaS).

Utility computing: It is a computing model that defines service provisioning techniques for services such as compute services along with other major services such as storage, infrastructure, etc which are provisioned on a pay-per-use basis. Thus, the above technologies contributed to the making of cloud computing. 

1.2 HARDWARE,INTERNET AND SOFTWARE,VIRTUALIZATION There are certain technologies working behind the cloud computing platforms making cloud computing flexible, reliable, and usable.

(A)Virtualization Virtualization is a technique, which allows to share single physical instance of an application or resource among multiple organizations or tenants (customers). It does this by assigning a logical name to a physical resource and providing a pointer to that physical resource when demanded.

The Multitenant architecture offers virtual isolation among the multiple tenants. Hence, the organizations can use and customize their application as though they each have their instances running.

Types of Virtualization A list of types of Virtualization is given below -How to find Nth Highest Salary in SQL

i.

Hardware virtualization

ii.

Server virtualization

iii.

Storage virtualization

iv.

Operating system virtualization

v.

Data Virtualization

Virtualization Concept Creating a virtual machine over existing operating system and hardware is referred as Hardware Virtualization. Virtual Machines provide an environment that is logically separated from the underlying hardware. The machine on which the virtual machine is created is known as host machine and virtual machine is referred as a guest machine. This virtual machine is managed by a software or firmware, which is known as hypervisor.

Hypervisor The hypervisor is a firmware or low-level program that acts as a Virtual Machine Manager. There are two types of hypervisor: Type 1 hypervisor executes on bare system. LynxSecure, RTS Hypervisor, Oracle VM, Sun xVM Server, VirtualLogic VLX are examples of Type 1 hypervisor. The following diagram shows the Type 1 hypervisor.

The type1 hypervisor does not have any host operating system because they are installed on a bare system. Type 2 hypervisor is a software interface that emulates the devices with which a system normally interacts. Containers, KVM, Microsoft Hyper V, VMWare Fusion, Virtual Server 2005 R2, Windows Virtual PC and VMWare workstation 6.0 are examples of Type 2 hypervisor. The following diagram shows the Type 2 hypervisor.

Types of Hardware Virtualization Here are the three types of hardware virtualization: 

Full Virtualization

 

Emulation Virtualization Paravirtualization

Full Virtualization In full virtualization, the underlying hardware is completely simulated. Guest software does not require any modification to run.

Emulation Virtualization In Emulation, the virtual machine simulates the hardware and hence becomes independent of it. In this, the guest operating system does not require modification.

Paravirtualization In Paravirtualization, the hardware is not simulated. The guest software run their own isolated domains.

VMware vSphere is highly developed infrastructure that offers a management infrastructure framework for virtualization. It virtualizes the system, storage and networking hardware.

(B) HARDWARE. A cloud network is made up of a variety of physical hardware that can be located at multiple geographical locations. The hardware includes networking equipment, like switches, routers, firewalls, and load balancers, storage arrays, backup devices, and servers.

(C) SOFTWARE       

Software-as-a-Service (Saas): Salesforce. Infrastructure-as-a-Service (Saas): DigitalOcean. Platform-as-a-Service (Saas): AWS. File Sharing + Data Storage: Dropbox. Big Data Analysis: Civis Analytics. Data Governance: Carbonite. Cybersecurity: Forcepoint. (D) INTERNET

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Dropbox, Facebook, Gmail. Cloud can be used for storage of files. ...

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Banking, Financial Services. Consumers store financial information to cloud computing serviced providers. ... Health Care. ... Education. ... Government. ... Big data Analytics. ... Communication. ... Business Process.

1.3 CLOUD SERVICE ATTRIBUTES 7 Critical Cloud Service Attributes Reliability. Business-critical services are just that: critical! ... Availability. Availability is related to reliability. ... Scalability. ... Security. ... Quality of Service (QoS) ... Service-Level Agreements (SLA) ... Support.

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(A) CLOUD PLATFORMS ACCESSED Cloud services are infrastructure, platforms, or software that are hosted by third-party providers and made available to users through the internet. ... Users can access cloud services with nothing more than a computer, operating system, and internet connectivity or virtual private network (VPN (B) CLOUD HOSTING

Cloud hosting is the procurement of computing resources from a cloud computing provider or facility to host data, services and/or solutions. Cloud hosting is an Infrastructure as a Service (IaaS) cloud delivery model that provides a suite of remote/virtual services. These are delivered on an on-demand basis and hosted on top of a cloud computing infrastructure. (C) INFORMATION TECHNOLOGY SUPPORT

Cloud Computing Technologies A list of cloud computing technologies are given below o

Virtualization

o

Service-Oriented Architecture (SOA)

o

Grid Computing

o

Utility Computing

Virtualization Virtualization is the process of creating a virtual environment to run multiple applications and operating systems on the same server. The virtual environment can be anything, such as a single instance or a combination of many operating systems, storage devices, network application servers, and other environments.

Types of Virtualization A list of types of Virtualization is given below -How to find Nth Highest Salary in SQL

vi.

Hardware virtualization

vii.

Server virtualization

viii.

Storage virtualization

ix.

Operating system virtualization

x.

Data Virtualization

Service-Oriented Architecture (SOA) Service-Oriented Architecture (SOA) allows organizations to access ondemand cloud-based computing solutions according to the change of business needs. It can work without or with cloud computing. The advantages of using SOA is that it is easy to maintain, platform independent, and highly scalable. Service Provider and Service consumer are the two major roles within SOA.

Applications of Service-Oriented Architecture There are the following applications of Service-Oriented Architecture o

It is used in the healthcare industry.

o

It is used to create many mobile applications and games.

o

In the air force, SOA infrastructure is used to deploy situational awareness systems.

The service-oriented architecture is shown below:

Grid Computing Grid computing is also known as distributed computing. It is a processor architecture that combines various different computing resources from multiple locations to achieve a common goal. In grid computing, the grid is connected by parallel nodes to form a computer cluster. These computer clusters are in different sizes and can run on any operating system. Grid computing contains the following three types of machines 1. Control Node: It is a group of server which administrates the whole network. 2. Provider: It is a computer which contributes its resources in the network resource pool. 3. User: It is a computer which uses the resources on the network.

Mainly, grid computing is used in infrastructures, and marketing research.

the ATMs,

back-end

Utility Computing Utility computing is the most trending IT service model. It provides ondemand computing resources (computation, storage, and programming services via API) and infrastructure based on the pay per use method. It minimizes the associated costs and maximizes the efficient use of resources. The advantage of utility computing is that it reduced the IT cost, provides greater...