Chapter-7 Introduction to Cloud Computing Cloud Computing
Slide 2
Definition: Cloud itself is a set of hardware, software,
networks, storage, services, and interfaces that enable the
delivery of computing as a service. Cloud services include the
delivery of software, infrastructure, and storage over the
internet( either as separate components or a complete platform)
based on user demand. The world of the cloud has lots of
participants: End user- Dont really have to know anything about the
underlying technology. Business management- Needs to take
responsibility for overall governance of data or services Cloud
service provider- responsible for IT assets and maintenance.
Slide 3
Overall the cloud embodies the following four basic
characteristics. Elasticity and the ability to scale up and down
Self service provisioning and automatic deprovisioning Application
programming interfaces(APIs) Billing and metering of service usage
in a pay-as-you go model. Elasticity:- user can request additional
resources on demand and just as easily deprovision those resources
when they are no longer needed.
Slide 4
Cloud Computing : Cloud Computing makes computer infrastructure
and services available "on-need" basis. The computing
infrastructure could include hard disk, development platform,
database, computing power or complete software applications. To
access these resources from the cloud vendors, organizations do not
need to make any large scale capital expenditures. Organization
need to "pay per use" i.e. organization need to pay only as much
for the computing infrastructure as they use. The billing model of
cloud computing is similar to the electricity payment that we do on
the basis of usage.
Slide 5
Self service provisioning :- Customer can easily get cloud
services without going through a lengthy process. The customer
simply request an amount of computing, storage, software, process,
or other resources from the service provider. Contrast this
on-demand response with the process at a typical data center. When
a department is about to implement a new application, it has to
submit a request to the data center for additional computing
hardware, software, services, or process resources.
Slide 6
Cloud Computing has the following characteristics: Availability
of large computing infrastructure on need basis: Cloud vendors
provide appearance of infinite computing infrastructure
availability. This is available to organizations on need basis.
This ensures that organizations do not need to set up servers for
their peak requirements. As an example consider the official
Wimbledon site. The site gets extremely high traffic in the two
weeks when the championship happens. For this two weeks period this
site will have high server usage. For rest of the year the site
will need to only pay for the reduced usage. In general
organizations do not need to bear the cost of computing
infrastructure for their peak loads. The usage of computing
resources can be increased or reduced on need basis, is called
elastic computing.official Wimbledon site
Slide 7
Cloud computing uses a "pay-per-use" billing model. Cloud
billing model are very different when compared to traditional IT
billing techniques. Typical billing models include per user
billing, per GB billing or per-use billing (i.e. an organization is
billed on each usage of the computing service). Cloud computing
typically does not involve long-term commitment to use the
computing infrastructure. The vendor does not enforce long-term
usage of services. Cloud computing does not involve any significant
capital expenditure for the organization. Unlike traditional IT
infrastructure, in cloud computing organizations just use the
computing services without procuring it. In some sense cloud
computing involves renting the computing resources instead of
buying them. As the figure below displays, unlike traditional
computing model, Cloud computing requires no capital expenditure to
acquire initial computing resources. The figure below is from cloud
computing wiki.cloud computing wiki
Slide 8
Since the cloud computing vendor provides services over the
web, these are available from any location. Cloud computing can be
ordered online without detailed formal contracts. Cloud computing
provides a level-playing field for smaller organizations. It allows
smaller organization access to computing infrastructure without
making any significant initial investment. As an example Mozy
online storage provides online backup using cloud computing
model.Mozy online storage Many experts believe that cloud computing
will lead to increased commoditization of computing resources.
Slide 9
Examples of Cloud Computing applications Hotmail.com was
launched in 1996, It is widely considered as the first cloud
computing application. The data is stored at the vendor servers,
and users could pay incrementally to increase disk space usage.
Many other services have emerged in the last decade that allows
users to store information (or perform processing) without paying
any upfront charges. These are typically consumer oriented
services. Twitter, myspace, Wikipedia, youtube, facebook, linkedin,
Google docs and blogger all have the characteristics are examples
of cloud computing. Companies that provide Hosting services for
diskspace storage, images, emails are all examples of cloud
computing Hotmail.comHosting services
Slide 10
Salesforce.com, founded in 1999, was the first successful
example of providing software as a service in the business to
business domain. Salesforce is a CRM tool for sales executives
providing features like managing customer details, running
promotions etc. Salesforce.com Google and Microsoft provide
development platforms that can be accessed with "pay-per-use"
billing model. All these services are examples of Cloud computing.
GoogleMicrosoft Amazon.com was one of the first vendors to provide
storage space and computing resources following the cloud computing
model. Amazon.com
Slide 11
Comparing cloud providers with traditional IT providers
Traditional IT service providers operate the hardware, software,
networks, and storage for its clients. While the customer pays the
licensing fees for the software, the IT service provider manages
the overall environment. The service provider operates the
infrastructure in its own facilities. With the Traditional IT
service provider, the customer signs a long-term contract that
specifies mutually agreed-upon service levels. These IT providers
typically customize an environment to meet the needs of one
customer.
Slide 12
Contd.. In the cloud model, the service provider might still
operate the infrastructure in its own facilities. However, the
infrastructure might be virtualized across the globe, meaning that
you may not know where your computing resources, applications, or
even data actually reside. Additionally, these service providers
are designing their infrastructure for scale, meaning that there
isnt necessarily a lot of customization going on.
Slide 13
Performance monitoring and measuring A service management
environment is an integrated approach for managing your physical
environments and IT systems. This environment must be able to
maintain the required service level for that organization. Service
management has to monitor and optimize the service or sets of
services. Service management has to consider key issues, such as
performance of the overall system, including security and
performance.
Slide 14
Supporting Business Agility One of the most immediate benefits
of cloud-based infrastructure services is the ability to add new
infrastructure capacity quickly and at lower costs. Therefore,
cloud services allow the business to gain IT resources in a self
service manager, thus saving time and money. A typical cloud
service provider has economies of scale (cost advantages resulting
in the ability to spread fixed costs over more customers) that the
typical corporation lacks.