chapter 8 – cloud computing

Enterprise SolutionsChapter 8 – Cloud Computing

Introduction

Cloud computing is a use of resources hardware and software that are delivered as a service.

The name has been derived as an abstraction of a shaped symbol for complex infrastructure it contains in the system diagram.

Basically used to denote networks in the diagrams of computing and communication systems.

Facilitates remote services with user’s data, software and computation.

By: Varsha Godbole 8 - Cloud Computing 2

Architecture


Cloud Service

(e.g.-Queue)

Cloud Platform (e.g.-Web Frontend)

Cloud Infrastructure

(e.g.-Billing VMs)Cloud Storage

(e.g.-Database)

Figure 1

Architecture continued…


Figure 1 shows the sample architecture of cloud computing.

Focus is mainly on the loose coupling of the components.

Multiple cloud computing components interact with each other.

Types


Private/ Internal

Hybrid

Public/ External

The Cloud

Off-premises/Third PartyOn-premises/Internal

Figure 2

Types continued…


Figure 2 shows types of cloud computing.

They are broadly classified as:

• Public Cloud

• Community Cloud

• Hybrid Cloud

• Private Cloud

Types continued…


Public Cloud:

• These applications, storage and other resources are made available to the general public by a service provider.

• Usually services offered by this type are free or pay-per-use model.

• The infrastructure is owned by the service provider and access made available using internet

• Mostly direct connectivity is not permitted.

• E.g.: Microsoft, Google and Amazon AWS.

Types continued…


Community Cloud:

• Infrastructure is shared by various communities having common cause.

• These can be managed internally or by third party and hosted internally or externally.

• Cost is shared by fewer users as compared to public cloud.

• Provides cost saving feature when compared with private cloud.

• E.g.: Security, Compliance, Jurisdiction etc.

Types continued…


Hybrid Cloud:

• Mostly a combination of two or more types of cloud computing types like private, community or public.

• Provides high degree of fault tolerance and can be used locally without having to dependent on internet connectivity.

• Requires both on-premises and off-premises cloud infrastructure.

• In context with in-house application this type is not useful when it comes to flexibility, security and certainty.

Types continued…


Private Cloud:

• Irrespective of the infrastructure management (internally or by third party and hosted internally or externally) this is used for a single organization.

• Resource utilization and organizational level involvement is very high.

• High risk of security issues if not addressed adequately.

• Benefits to the organization in terms of increasing profit when executed and maintained properly.

Service Models


Cloud ClientsWeb browser, Mobile app, thin client, terminal emulator.

SaaSCRM, Email, Virtual desktop, Communication, games

PaaSExecution runtime, database, web server development tools.

IaaSVirtual machines, servers, storage, load balancers, network.

Figure 3

Application

Platform

Infra-structure

Service Models continued…


Figure 3 shows fundamental models provided by cloud computing services

They are broadly classified as:

• Infrastructure as a Service (IaaS)

• Platform as a Service (PaaS)

• Software as a Service (SaaS)



Infrastructure as a Service (IaaS):

• Very basic model offered by cloud computing services

• Here providers offers computers as physical or most often as virtual machines along with other resources

Platform as a Service (PaaS):

• Computing platform is provided including operating system, programming languages, database servers and web servers.



• It benefits the application programmers to develop and execute their software solutions without baring the cost and maintenance of underlying hardware and software layers.

Software as a Service (SaaS):

• Here the software application are installed and operated by cloud providers while users access them using cloud clients.

• Cloud users need not know and manage the cloud infrastructure and platform on which the applications are running.



• Thus it minimizes the maintenance and support of these applications as cloud user need not install and run these application on their own computers.

• Major advantage behind this is, multiple tasks can be executed at run time with the help of virtual machines and is capable of achieving changing work demand.

• Pricing is usually monthly basis or flat fees for the year per user.

Cloud Clients


Users of cloud computing can access the services using network client devices such as desktop computers, laptops, tablets and smart phones.

Many cloud applications can be accessed using internet and web browsers.

Applications like virtual desktop and most of the e-mail use specific type of client.

Screen-sharing mechanism is used to access the some of the legacy applications

Characteristics


Agility: improves users’ ability to re-provision technological infrastructure resources.

API: Cloud computing systems typically use REST (Representational State Transfer) based API

Cost: Reduction in the cost as the infrastructure is provided and managed by third party and there is no sub-sequent purchase required per computing task.

Device and Location independence: User can access systems using web browser though he/she is located everywhere

Characteristics continued…


Virtualization: Resources like hardware platforms, operating systems, network devices and storage devices are virtual (rather physical) in nature.

Reliability: Is improved if multiple redundant sited are used. This benefits business in terms of disaster recovery and business continuity.

Performance: Is monitored and consistent and loosely coupled architectures are constructed using web services as the system interface

Scalability and Elasticity: On Demand provisioning of resources on a fine-grained, self service basis near real-time, without users having to engineer for peal loads.

Characteristics continued…


Multi-tenancy: Enables sharing of resources and costs across a large pool of users. This further benefits from centralization, peak-load capacity, utilization and efficiency.

Security : When compared with other traditional systems, cloud computing provided required amount of security for the users.

Maintenance: As these are not required to be installed on each of the user’s computer system, maintenance becomes pretty easy.

Issues


Privacy:

• Very important with respect to legal compliance and user trust and needs to be considered at every phase of design.

• User must take care and be aware of the privacy measures taken by the cloud provider before using as online service.

• Protecting the organizational and customer data should be a key factor when evaluating the vendors of cloud computing.

Similar Systems and Concepts


Autonomic Computing: Computer systems capable of self-management.

Client-Server Model: Distributed applications having servers (service providers) and clients (service requesters)

Grid Computing: A form of distributed and parallel computing.

Mainframe Computer: Mainly used for large scale applications like bulk data processing required for census, police and secrete intelligence services.

Similar Systems and Concepts


Utility Computing: The packaging of computing resources such as computation and storage, as a metered service.

e.g. Electricity services Peer to Peer: Distributed architecture without the need for

any central co-ordination. Cloud gaming: Gaming data is stored at provider’s server

and made available to the users on demand.

chapter 8 – cloud computing

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