CloudComputing

101

Otto I. MoraGeorgia Tech MBA IT Club

Computing Paradigm Evolution

MainframeComputing

PersonalComputing Client/Server

Computing

MobileComputing

CloudComputing

Cloud Computing has 3 layers:Application

Platform

Infrastructure

Software and services

Operating System on which to build

and run your applications.

Physical Hardware on which to run the Operating

System.

... and all 3 can be delivered and managed over the internet as a service.

Formal NIST definition of Cloud Computing here: http://alturl.com/dmk8t

Software as Service (SaaS)• Software delivery model in which software

and its associated data are hosted centrally (typically in the Internet cloud).

• No need to pay license, subscription model (pay as you go like utility bill).

Thin “Cloud Clients”SaaS Provider

Software as Service (SaaS)• Key target audience: End Users (both

companies and consumers).• Examples:

SaaS Customer Relationship Management (CRM) provider. Google Apps: SaaS provider of

email, calendar and office documents (spreadsheet, word processing, etc)

Online Exchange Server (email), Sharepoint (document collaboration and sharing and Office Web Apps.

Platform as Service (PaaS)

• Provides both a computing platform and a solution stack as a service.

Build

Build the application the in PaaS provider’s OS platform.

Host Scale

Host it in the PaaS provider’s computing hardware.

Cloud OS systems are able to dynamically scale according to demand.

Platform as Service (PaaS)

• Key target audience: Developers (“come run your code on our platform”) and Companies (“port your applications to our platform”).

• Examples:

MS Solution, able to run .NET, Java, PHP and others. Worldwide CDN across 24 datacenters.

Google App Engine: Allows Python, Java, PHP, JRuby and others. Uses GQL instead of SQL (google specialized database system). Wide availability of APIS .

One of the pioneers in PaaS, originally built on Ruby. First to implement “polyglot” (support for several programming languages). Popular use of NoSQL.

Infrastructure as a Service (SaaS)

• Facilitated by Virtualization: Computers are able “emulate” others. Think of a “a dream inside a dream”, or translating from one language to another in your head, or running SNES games on your pc. The PC “emulates” the SNES hardware.

Infrastructure as a Service (IaaS)

• Well… if you can run one Nintendo inside your pc… You can probably run two if you have a powerful enough computer….

Infrastructure as a Service (IaaS)

• …. Or several with a powerful server.

• The necessary requirement is only that we “package” these virtual computers so that they are able to run independently and concurrently on the same hardware. Virtual computers are packaged into virtual “image files”.

Infrastructure as a Service (IaaS)• Cloud providers offer computers – as physical

or more often as virtual machines, as an on demand service from large pools of hardware resources in their data center.

• Cloud users then install operating system images on the machines as well as their application software

Linux Mail

Server

Windows Sharepoint

Server

Oracle Database

Server

Infrastructure as a Service (IaaS)• Key target audience: IT Departments (“don’t

buy and own your own hardware infrastructure instead rent it from us on a per use basis”)

• Examples:

Virtual Infrastructure management tool. Used by Rackspace and NASA. Allows companies to provide cloud computing services using commodity hardware.

Amazon EC2 allows users to rent virtual computers on which to run their own computer applications. The underlying infrastructure uses the Xen Virtual Hypervisor.

Barriers to Adoption of the Cloud

• Education and expertise (to move beyond the marketing abuse of the word cloud).

• Data security concerns (results in “private clouds”).

• Governance (lack of tools to easily manage scaling up and down).

• Economies of scale (pooling of enough demand together to create momentum).

• Danger of “lock in”, need ability to easily transfer from one provider to another.