demystifying the cloud.pdf

8/14/2019 Demystifying The Cloud.pdf

1/55

2012 Janakiram & Associates 1

Demystifying the Cloud

This eBook explains the concepts of Cloud Computing in

simple terms. The first three chapters introduce the key

concepts and the terminologies of the Cloud. The

remaining chapters cover the major implementations of

the Cloud Computing including Amazon Web Services,

Microsoft Windows Azure Platform, Google App Engine,

OpenStack and Cloud Foundry. This is targeted towards

the beginners and intermediate developers with a basic

understanding of web technologies.

GetCloud Ready

2012

Janakiram MSV

www.GetCloudReady.com

1/1/2012


2/55


About the Author

A technologist at heart, I have been championing

Distributed Computing for the last 14 years.

In my current role of an unbiased, neutral Cloud

Specialist, I offer strategic advice and coaching to

enterprises and start-ups. I help them adopt and

take advantage of the Cloud. Founder and driving

force of an initiative called GetCloudReady.com, I

enable Architects, Developers and IT Professionals to be ready for the cloud and thereby get

people, processes, products and business applications to leverage the benefits of the cloud.

My greatest imaginable dream is to continue to be the catalyst to the cloud revolution by

being an independent authority on Cloud Computing as a Blogger, a Cloud Evangelist, a

Speaker, an Advisor and Mentor to startups.

I am also the chief editor at CloudStory.in where I blog about the latest trends in Cloud

Computing. As a passionate speaker, I have chaired the Cloud Computing track at premier

events in India. Having spoken at over 50 events in 2011, I have been consistently rated as

the top speaker at premier technical events.

The valuable time and work done at Amazon as the Web Services Evangelist and Technology

Architect Cloud at Microsoft Corporation has offered me the breadth and depth of

knowledge and expertise in the Cloud Computing domain. Prior to this, for about 10 years at

Microsoft Corporation, I have been involved in selling, marketing and evangelizing the

Microsoft Application Platform and Tools.

Founded on a strong belief that technology needs to create a lasting impact on businesses,

people and society at large; I relentlessly strive to deliver value to my customers and the

community.

My Coordinates

Principal Consultant,Principal Consultant,Principal Consultant,Principal Consultant, Janakiram & Associates http://www.janakiramm.net

Cloud SpecialistCloud SpecialistCloud SpecialistCloud Specialist,,,, Get Cloud Ready http://www.GetCloudReady.com

Chief EditorChief EditorChief EditorChief Editor,,,, CloudStory.in http://www.CloudStory.in


3/55


Chapter 1Chapter 1Chapter 1Chapter 1

Defining the CloudDefining the CloudDefining the CloudDefining the Cloud

Evolution of ISPEvolution of ISPEvolution of ISPEvolution of ISP

There are multiple factors that led to the evolution of Cloud Computing. One

of the key factors is the way Internet Service Providers (ISP) matured over a

period of time. I am borrowing this analogy from Forrester Research.

Evolution of ISPEvolution of ISPEvolution of ISPEvolution of ISP

From the initial days of offering basic Internet connectivity to offering

Software as a Service (SaaS), the ISPs have come a long way. ISP 1.0 was all

about providing Internet access to their customers. ISP 2.0 was the phase

where ISPs offered hosting capabilities. The next step was co-location

through which the ISPs started leasing out the rack space and bandwidth. By


4/55


this, companies could host their servers running custom, Line of Business

(LoB) applications that could be accessed over the public internet by its

employees, trading partners and customers. ISP 3.0 was offering

applications on subscription resulting in the Application Service Provider

(ASP) model. The latest trend of Software as a Service is a mature ASP

model. The next logical step for ISPs would be to embrace the Cloud.

The Programmable WebThe Programmable WebThe Programmable WebThe Programmable Web

Web Services made the web programmable. They enabled the developers to

look at the Internet as a class library or an object model. Protocols like

Simple Object Access Protocol (SOAP), Representational State Transfer

(REST), JavaScript Object Notation (JSON) and Plain Old XML (POX) fueled

the growth of APIs on the web. Today every popular search engine, social

networking site and syndication portal have APIs exposed to developers.

Programmable WebProgrammable WebProgrammable WebProgrammable Web

VirtualizationVirtualizationVirtualizationVirtualization

Virtualization is the most discussed term among CIOs and IT decision

makers. Through Virtualization, the data center infrastructure can be

consolidated from hundreds of servers to just tens of servers. All the

physical server roles like Web Servers, Database Servers and Messaging

Servers run as virtualized instances. This results in lower Total Cost of


5/55


Ownership (TCO) and brings substantial savings on the power bills and

reduced cost of cooling equipment.

Virtualized InfrastructureVirtualized InfrastructureVirtualized InfrastructureVirtualized Infrastructure

Though the evolution of ISP, programmable web and virtualization are

independent trends, they contribute to the evolution of Cloud Computing.

Understanding Cloud ComputingUnderstanding Cloud ComputingUnderstanding Cloud ComputingUnderstanding Cloud Computing

If you are wondering what is so special about the Cloud in Cloud Computing,

here is an explanation- Traditionally, developers and architects used a

picture of cloud to illustrate a remote resource connected via the web.


6/55

2012 Janakiram & Associates

Eventually cloud became the logical connector between the local and remote

resources on the Internet.

Most of the developers get confused when they encounter the term Cloud

Computing. According to them, their Web Services are already hosted on the

Cloud and that can be potentially called as Cloud Services. While there is

some truth in this argument, it is a not very accurate way of describing Cloud

Computing. Lets look at Cloud Computing through the eyes of a developer.

Think Web ServicesThink Web ServicesThink Web ServicesThink Web Services

Most of the developers are familiar with Web Services. Web Services are

based on a few simple concepts. Every Web Service accepts a request and

returns a response (even if there is no explicit return value, a HTTP 200 OK

return value is considered as a response). They are units of code that can be

invoked over the web. Typically, Web Services accept one or more input

parameters and invoke processing logic which will result in an output. Web

Services are a part of web applications that run on a typical stack that has

hardware, a Server OS, application development platform. For a while, think

how you can expose every layer that is powering your web application as a

Web Service.

Web Services StackWeb Services StackWeb Services StackWeb Services Stack


7/55

2012 Janakiram & Associates !

Cloud OSCloud OSCloud OSCloud OS

Visualize a scenario where the hardware and the Operating System (OS) are

exposed as a Web Service over the public Internet. Based on the principles of

Web Services, we could send a request to this service along with a few

parameters. Since the OS is expected to act as an interface to the CPU and

the devices, we can potentially invoke a service that accepts a job that will

be processed by the OS and the underlying hardware. Technically, this Web

Service has just turned the OS + H/W combination into a Service. We can

start consuming this service by submitting CPU intensive tasks to this new

breed of Web Service. What do you call an OS that is exposed on the web as a

service? May be a Cloud OS? We will answer this in the coming sections.

Exposing the hardware and the OS as a ServiceExposing the hardware and the OS as a ServiceExposing the hardware and the OS as a ServiceExposing the hardware and the OS as a Service

Cloud FXCloud FXCloud FXCloud FX

Developers always develop and deploy their applications on the application

development platforms. Some of the most popular application developmentplatforms are .NET and Java. In the last scenario, we have seen how the OS +

H/W combination is offered as a service. Now, imagine a scenario where the

application development platform is offered to you as a service. Through

this, you will be able to develop and test your applications on a low end,

inexpensive notebook PC but will able to submit the code to run on the most

powerful hardware infrastructure. It is the same programming language,

SDK and the runtime that runs on your development environment. If the


8/55

2012 Janakiram & Associates "

hardware, OS, the language runtime and the SDK are offered to you as a

service, what would you call this? A Cloud Platform or may be Cloud FX? We

will address this in the next section.

Exposing the Runtime + SDK as a ServiceExposing the Runtime + SDK as a ServiceExposing the Runtime + SDK as a ServiceExposing the Runtime + SDK as a Service

Cloud ApplicationCloud ApplicationCloud ApplicationCloud Application

Today, most of the traditional desktop applications like word processors and

spreadsheet packages are available over the web. These new breed of

applications just need a browser and offer high fidelity with the desktop

software. This fundamentally changes the way software is deployed and

licensed. You need not double click setup.exe to install an Office suite on

your desktop. Just subscribe to the applications and the features that you

need and only pay for what you use. This is almost equivalent to exposing the

application as a service. These applications may be called as Cloud

Applications. We will take a relook at this later.

Web AppWeb AppWeb AppWeb Applicationlicationlicationlication as a Serviceas a Serviceas a Serviceas a Service


9/55

2012 Janakiram & Associates #

Welcome to the World of ServicesWelcome to the World of ServicesWelcome to the World of ServicesWelcome to the World of Services

Infrastructure as a ServiceInfrastructure as a ServiceInfrastructure as a ServiceInfrastructure as a Service

In the previous section we discussed the Cloud OS. All that the Cloud OS

offers is the infrastructure services. You may choose to use REST API to

manage this OS or use SSH or Remote Desktop console. Technically, when

you are able to delegate a program to execute on a remote OS running on theWeb, you are leveraging Infrastructure as a Service (IaaS). This is different

from classic web hosting. Web hosting only hosts web pages and cannot

execute code that needs low level access to the OS API. Web hosting cannot

dynamically scale on demand. IaaS enables you to run your computing task

on virtually unlimited number of machines. Remember that through IaaS,

you have just moved a server running in your backyard into the Cloud. You

are still responsible for managing, patching, securing and the health of the

remote servers. Amazon EC2, Rackspace, IBM SmartCloud and OpenStack

are examples of commercial IaaS offering.

Cloud OS = Infrastructure as a ServiceCloud OS = Infrastructure as a ServiceCloud OS = Infrastructure as a ServiceCloud OS = Infrastructure as a Service

Platform as a ServicePlatform as a ServicePlatform as a ServicePlatform as a Service


10/55


Platform as a Service or PaaS goes one level above the Cloud OS. Through

this, developers can leverage a scalable platform to run their applications.

The advantage of PaaS is that the developers need not worry about installing,

maintaining, securing and patching the server. The PaaS provider takes the

responsibility of the infrastructure and exposes the platform alone as a

service. Through this, the developers can achieve higher level of scalability,

reliability and availability of their applications. Microsoft Windows Azure,

Google App Engine, Force.com, Heroku, Engine Yard and Cloud Foundry are

some of the examples of PaaS.

Cloud FX = Platform as a ServiceCloud FX = Platform as a ServiceCloud FX = Platform as a ServiceCloud FX = Platform as a Service

Software as a ServiceSoftware as a ServiceSoftware as a ServiceSoftware as a Service

Software as a Service (SaaS) is a silent revolution in the world of traditional

software products. With the availability of tablets and inexpensive netbookscombined with abundant bandwidth, most of the applications are moving to

the Cloud to be offered as services. Consumers can now use inexpensive

devices that are capable of connecting to the web to get their work done. This

reduces the upfront investment in software and brings the Pay-as-you-go

model. Google Apps, Salesforce.com and Microsoft Office365 are examples

of SaaS.


11/55


Cloud App = Software as a ServiceCloud App = Software as a ServiceCloud App = Software as a ServiceCloud App = Software as a Service

What does CloudWhat does CloudWhat does CloudWhat does Cloud Computing mean to you?Computing mean to you?Computing mean to you?Computing mean to you?

IT Professionals and System AdministratorsIT Professionals and System AdministratorsIT Professionals and System AdministratorsIT Professionals and System Administrators

For IT Professionals, Cloud Computing is all about consolidation and

outsourcing the infrastructure. They are typically focused on the

Infrastructure as a ServiceInfrastructure as a ServiceInfrastructure as a ServiceInfrastructure as a Service. IT Pros will move away from managing

individual servers in their data centers to using a unified console to manage,

track and monitor the health of the remote server instances running on the

Cloud.

IaaS is the focus area of IT Pros and system administratorsIaaS is the focus area of IT Pros and system administratorsIaaS is the focus area of IT Pros and system administratorsIaaS is the focus area of IT Pros and system administrators

Developers and ArDevelopers and ArDevelopers and ArDevelopers and Architectschitectschitectschitects

Platform as a ServicePlatform as a ServicePlatform as a ServicePlatform as a Service is an offering meant for developers and architects.They need to design applications keeping the statelessness of the Cloud.


12/55


Architects should start thinking about the patterns that will make the

applications seamlessly scale on-the-fly across hundreds of servers.

PaaS is the focus area of developers and architectsPaaS is the focus area of developers and architectsPaaS is the focus area of developers and architectsPaaS is the focus area of developers and architects

ConsumersConsumersConsumersConsumers

Consumers will experience the Cloud through a variety of applications that

they will use in their day-to-day life. If you have ever used Google Docs,

Dropbox or Microsoft Live Mesh, you have already leveraging the Cloud.

Consumers will subscribe to Software as a ServiceSoftware as a ServiceSoftware as a ServiceSoftware as a Serviceofferings.

SaaS delivers software through a subscription for the consumersSaaS delivers software through a subscription for the consumersSaaS delivers software through a subscription for the consumersSaaS delivers software through a subscription for the consumers


13/55



The TenetsThe TenetsThe TenetsThe Tenets of the Cloudof the Cloudof the Cloudof the Cloud

The 4 Key TenetsThe 4 Key TenetsThe 4 Key TenetsThe 4 Key Tenets

I want to quickly recap the definition of Cloud Computing. It is all about

outsourcing your infrastructure and applications to run on a remote

resource. The remote resource phrase in the definition can be misleading

and creates an illusion that running your web app on a server hosted abroad

is Cloud Computing. So, what qualifies the remote resource to be called as

the Cloud?

Here are the 4 key capabilities that the Cloud Computing offers:

ElasticityElasticityElasticityElasticity

This is the most important attribute of the Cloud. You might start runningyour application on just a single server. But in no time, Cloud Computing

enables you to scale your application to run on 100s of servers. Once the

traffic and usage of your application decreases, you can scale down to

10s of servers. All this happens almost instantly and the best thing is

your application and your customers dont even realize that. This dynamic

capability of scaling up and scaling down is called Elasticity. Elasticity

brings an illusion of Infinity. Though nothing is infinite in this world, your

application can get any number of resources as it demands. This is the

biggest promise of the Cloud. Now, think of web hosting. When you want

to add another server to your web application, your hoster has to

manually provision that for you. Adding additional servers and

configuring the network topology introduces additional time lag that your

business cannot afford. Most of the Cloud Computing vendors offer an


14/55


intuitive way of manipulating your server configuration and topology.

Elasticity is the single most important attribute of the Cloud.

Elasticity of Cloud ComputingElasticity of Cloud ComputingElasticity of Cloud ComputingElasticity of Cloud Computing

PayPayPayPay----ByByByBy----UseUseUseUse

Elasticity and Pay-By-Use attributes go hand in hand. When you are

scaling up your application by adding more resources, you know how

much it is going to cost you. Pay-By-Use is a boon for the startups. As an

entrepreneur, you got to balance your investment between human

resources and IT resources. The biggest benefit of Pay-By-Use is that it

reduces the CAPEX and turns your IT investment into OPEX. The analogy

that I typically use is that of Cable or DTH TV subscription. During the

season of Cricket World Cup or NBA, you would want to subscribe to the

sports channels and unsubscribe that moment the event is over. With

Pay-By-Use, you can subscribe and unsubscribe to the IT infrastructurebased on your needs and you only pay for what you use. This is the most

optimal way of spending your IT budget.

Self ServiceSelf ServiceSelf ServiceSelf Service

When you are able to enjoy the capability of scaling up and scaling down

and only pay for what you use, you never want to wait for someone in the

datacenter to add an additional server to your application. Cloud can


15/55


deliver its promise only when there is self service. Through this, you can

control the resources all by yourself without an intermediary. When you

add a new CPU core, a server instance or add extra storage, you do it by

yourself by using the Console offered by the Cloud provider. This results

in reduction in IT support and maintenance. Today most of the

organizations have dedicated IT teams to provision a new machine,

storage, collaboration portal and mailboxes as a part of on-boarding the

new employees. Through Self Service, a fairly non-technical person can

achieve these tasks and you dont need certified system administrators to

do this. For example, when you sign up with Google Apps, it is very simple

and intuitive to configure the mailboxes for the employees. With more

and more applications moving the Cloud, Self Service becomes the

preferred way of configuring and managing the IT infrastructure.

AWS Management ConsoleAWS Management ConsoleAWS Management ConsoleAWS Management Console


16/55


Microsoft Windows Azure Management PortalMicrosoft Windows Azure Management PortalMicrosoft Windows Azure Management PortalMicrosoft Windows Azure Management Portal

ProgrammabilityProgrammabilityProgrammabilityProgrammability

This is the critical attribute of the Cloud. The Cloud makes the developers

extremely important. Developers are familiar with the concepts of

multithreading where they spawn new threads to achieve scalability and

the responsiveness of the application. They incorporate logic to create

additional threads on demand. The programmability aspect of the Cloud

adds a new dimension to the development. Developers can now create

additional machines and add it to the applications on demand. They can

treat the entire data center, servers and machines as an object model

that be programmed. They can now do a For-Each loop on every server

instance and decide what do with each instance. Amazon Web Services

have the most mature API for programmatically controlling the Cloud

based resources. Windows Azure supports the management API that lets

developers programmatically deploy and manage Azure applications. By

leveraging these APIs, developers are building applications to manage

the infrastructure and some of these frontends run on iPad and Android

devices. Now, imagine tapping on your mobile phone to add a dozen


17/55

2012 Janakiram & Associates 1!

servers to your application. Thanks to the Cloud! Developers are

important more than ever!

AWS SDK for .NETAWS SDK for .NETAWS SDK for .NETAWS SDK for .NET Visual StudioVisual StudioVisual StudioVisual Studio

AWS PlugAWS PlugAWS PlugAWS Plug----in for Eclipsein for Eclipsein for Eclipsein for Eclipse


18/55

2012 Janakiram & Associates 1"

iPhone App to manage AWSiPhone App to manage AWSiPhone App to manage AWSiPhone App to manage AWS

So, lets summarize what we just discussed. Cloud Computing has 4 key

tenets

1) Elasticity, 2) Pay-By-Use, 3) Self Service, and 4) Programmability.

Hosting vs. Cloud ComputingHosting vs. Cloud ComputingHosting vs. Cloud ComputingHosting vs. Cloud Computing

Revisiting the on-going debate of hosting vs. Cloud Computing, lets see what

attributes hosting model exposes. Hosting can never meet the promise of

elasticity. Even if it does, it wont match the economics of the Cloud. Hosting

does offer some level of Self Service but not to an extent of manipulating the

server configuration on the fly! Pay-By-Use attribute is emulated by some

hosting companies. But, it is not a norm in the hosting business.

Programmability is too expensive to be supported by hosters as they cannot

invest in the SDK and tools to manage the infrastructure. So, it is clearly

evident that hosting is not the same as Cloud Computing.

Having understood the key attributes of the Cloud, you might start wondering

how you can bring these capabilities to your data center in the enterprise.

The reality is that these capabilities can be applied to your data center and

officially that is called as the Private Cloud. It is time for us to discuss


19/55

2012 Janakiram & Associates 1#

various implementations of the Cloud. We will look at 4 different

mechanisms the way Cloud can be implemented.

Hosting vs. theHosting vs. theHosting vs. theHosting vs. the CloudCloudCloudCloud

The 4 Implementations of the CloudThe 4 Implementations of the CloudThe 4 Implementations of the CloudThe 4 Implementations of the Cloud

Public CloudPublic CloudPublic CloudPublic Cloud

This is the most popular incarnation of the Cloud. Many businesses and

individuals realize Cloud through the Public Cloud implementation. It needs

a huge investment and only well established companies with deep pockets

like Microsoft, Amazon and Google can afford to set them up. Public Cloud is

implemented on thousands of servers running across hundreds of data

centers deployed across tens of locations around the world. The best thing

about Public Cloud is that the customers can choose a location for his

application to be deployed. This will reduce the latency when the consumers

access the application. For example, a London based business can choose to

deploy their app at the Europe data center and an American company prefersa data center in North America. With the geographical spread, Public Clouds

like Amazon Web Services, Rackspace and Microsoft Windows Azure also

offer Content Delivery Network (CDN) features. Through this, static content

will be automatically cached across all the data centers around the globe

thus increasing the scalability of the application and offering better user

experience to end-users.


20/55


Public CloudPublic CloudPublic CloudPublic Cloud

Private CloudPrivate CloudPrivate CloudPrivate Cloud

Simply put, Private Clouds are normal data centers within an enterprise with

all the 4 attributes of the Cloud Elasticity, Self Service, Pay-By-Use and

Programmability. By setting up a Private Cloud, enterprises can consolidate

their IT infrastructure. They will need fewer IT staff to manage the data

center. They will also realize reduced power bills because of the low

electricity consumption and lesser cooling equipment needs. Private Cloud

empowers employees within an organization through Self Service of their IT

needs. It becomes easy to provision new machines and quickly assign them

to project teams. Private Cloud borrows some of the best practices of Public

Cloud but limited to an organizational boundary. Private Cloud can be setup

using a variety of offerings from vmWare, Microsoft, IBM, SUN and others.

There are also some of the Open Source implementations like Eucalyptus

and OpenStack. We will discuss more of Private Cloud in the coming

episodes.


21/55


Private CloudPrivate CloudPrivate CloudPrivate Cloud

Hybrid CloudHybrid CloudHybrid CloudHybrid Cloud

There are scenarios where you need a combination of Private Cloud and

Public Cloud. Due to the regulations and compliance issues in few countries,

sensitive data like citizen information, patient medical history, and financial

transactions cannot be stored in servers that physically not located within

the political boundaries of a country. In some scenarios, the enterprise

customers want to get best of the both worlds by logically connecting their

Private Cloud and the Public Cloud. Through this, they can offer seamless

scalability by moving some of the on-premise and Private Cloud based

applications to the Public Cloud. Security plays a critical role in connecting

the Private Cloud to the Public Cloud. Realizing its importance, Amazon Web

Services offers Virtual Private Cloud (VPC) that securely bridges Private

Cloud and Amazon Web Services. It is a way of extending your infrastructure

beyond the organizational boundary and the firewall in a secure way.

Windows Azure AppFabric brings the concept of Hybrid Cloud to Microsofts

enterprise customers.


22/55


Hybrid CloudHybrid CloudHybrid CloudHybrid Cloud

Community CloudCommunity CloudCommunity CloudCommunity Cloud

Community Cloud is implemented when a set of businesses have a similar

requirement and share the same context. This would be made available to a

set of select organizations. For example, the Federal government in US may

decide to setup a government specific Community Cloud that can leveraged

by all the states. Through this, individual local bodies like state governments

will be freed from investing, maintaining and managing their local data

centers. Similarly, the Reserve Bank of India (RBI) or Unique Identification

Authority of India (UIDAI) may setup a Community Cloud for all the financial

institutions that share common goals and requirements. So, a Community

Cloud is a sort of Private Cloud but goes beyond just one organization.

Community CloudCommunity CloudCommunity CloudCommunity Cloud


23/55



24/55



The Anatomy of the CloudThe Anatomy of the CloudThe Anatomy of the CloudThe Anatomy of the CloudIntroduction to VirtualizationIntroduction to VirtualizationIntroduction to VirtualizationIntroduction to Virtualization

Virtualization is abstracting the hardware to run virtual instances of multiple

guest operating systems on a single host operating system. You can see

Virtualization in action by installing Microsoft Virtual PC, VMware Player or

Oracle VirtualBox. These are desktop virtualization solutions that let you

install and run an OS within the host OS. The virtualized guest OS images arecalled Virtual Machines. The benefit of virtualization is realized more on the

servers than on the desktops.

Server VirtualizationServer VirtualizationServer VirtualizationServer Virtualization

There are many reasons for running Virtualization on the servers running in

a traditional data center. Here are a few:

Mean Time To RestoreMean Time To RestoreMean Time To RestoreMean Time To Restore

It is far more flexible and faster to restore a failed web server, app server or

a database server that is running as a virtualized instance. Since these

instances are physical files on the hard disk for the host operating system,

just copying over a replica of the failed server image is faster than restoring

a failed physical server. Administrators can maintain multiple versions of the


25/55


VMs that come handy during the restoration. The best thing about this is that

the whole copy and restore process can be automated as a part of disaster

recovery plan.

Maximizing the server utilizationMaximizing the server utilizationMaximizing the server utilizationMaximizing the server utilization

It is very common that certain servers in the data center are less utilized

while some servers are maxed out. Through virtualization, the load can be

evenly spread across all the servers. There are management software

offerings that will automatically move VMs to idle servers to dynamically

manage the load across the data center.

Reduction in maintenance costReduction in maintenance costReduction in maintenance costReduction in maintenance cost

Virtualization has a direct impact on the bottom line. First, by consolidatingthe data center to run on fewer but powerful servers, there is a significant

cost reduction. The power consumed by the data center and the maintenance

cost of the cooling equipment comes down drastically. The other problem

that virtualization solves is the migration of servers. When the hardware

reaches the end of the lifecycle, the physical servers need to be replaced.

Backing up and restoring the data and the installation of software on a

production server is very complex and expensive. Virtualization makes this

process extremely simple and cost effective. The physical servers will be

replaced and the VMs just get restarted without any change in the

configuration. This has a significant impact on the IT budgets.

Efficient managementEfficient managementEfficient managementEfficient management

All major virtualization software have a centralized console to manage,

maintain, track and monitor the health of physical servers and the VMs

running on these servers. Because of the simplicity and the dynamic

capabilities, IT administrators will spend less time in managing the

infrastructure. This results in better management and cost savings for the

company.

Virtualization on the ServerVirtualization on the ServerVirtualization on the ServerVirtualization on the Server

Lets understand more about the server virtualization. Typically the OS is

designed to act as an interface between the applications and the hardware. It

is not specifically designed to run the guest OS instances on top of it.


26/55


An OS Managing the ApplicationsAn OS Managing the ApplicationsAn OS Managing the ApplicationsAn OS Managing the Applications

In fact, in the server virtualization scenario, the host OS is not very

significant. It is just confined to booting up and running the VMs. Given the

fact that the OS is not ideal for running multiple VMs and has a little role to

play, there is a new breed of software called Hypervisor that takes over the

OS. Hypervisor is an efficient Virtual Machine Manager (VMM) that is

designed from the ground up to run multiple high performant VMs. So, a

Hypervisor is to VMs what an OS is to processes.

A HypervisorA HypervisorA HypervisorA Hypervisor Managing theManaging theManaging theManaging the Virtual MachinesVirtual MachinesVirtual MachinesVirtual Machines

A Hypervisor can potentially replace the OS and can even boot directly from a

VM. This is called bare metal approach to virtualization. These Hypervisors

have low footprint of few megabytes (vmWare ESXi is just 32MB in size!) and

have an embedded OS with them. Hypervisors are assisted by the hardwarevirtualization features built into the latest Intel and AMD CPUs. This

Operating System

Ap

Ap

Ap

Ap

Ap

Ap

Hardware

Hypervisor

VM VM VM VM VM VM

Hardware


27/55


combination of hardware and Hypervisor turns the server into a lean and

mean machine to host multiple VMs. The VM that is used by the Hypervisor to

boot as a host is called a para-virtualized VM. This concept makes

virtualization absolutely powerful. Imagine a server booting in few seconds

and the required para-virtualized (host) VM gets copied over a gigabitEthernet to run multiple guest VMs. This enables the datacenter to be very

dynamic and agile. The Hypervisor can be controlled by a central console and

can be instructed about the host VM to boot and the guest VMs to be run on it.

A look at the Hypervisor marketA look at the Hypervisor marketA look at the Hypervisor marketA look at the Hypervisor market

Citrix XenServerCitrix XenServerCitrix XenServerCitrix XenServer

This product is based on the proven, open source Hypervisor called Xen.

Xens paravirtualization technology is widely acknowledged as the fastest

and most secure virtualization software in the industry and it is enhanced by

taking full advantage of the latest Intel VT and AMD-V hardware

virtualization assist capabilities. This product is free and can be downloaded

from Citrix.com.

VMware ESXiVMware ESXiVMware ESXiVMware ESXi

HardwareH ervisor

Paravirtualized VM

VM VM VMApp App App AppApp App

.


28/55


This product is another bare metal Hypervisor from the virtualization leader,

VMware. This is one of the best Hypervisors with just 32MB footprint. ESXi

ships with Direct Console User Interface (DCUI) that provides basic UI

required for administering and managing the Hypervisor. Through its

standard Common Information Model (CIM) system, it also exposes the APIsto control the infrastructure.

Microsoft HyperMicrosoft HyperMicrosoft HyperMicrosoft Hyper----V ServerV ServerV ServerV Server

This is a free Hypervisor from Microsoft based on the same Hypervisor that

ships with Microsoft Windows Server Hyper-V edition. This is best suited for

Virtual Desktop Infrastructure (VDI) because of its compatibility with

Windows Vista and Windows 7. Hyper-V does not have any local GUI but can

be managed from System Center Virtual Machine Manager (SCVMM).

Virtualization and the CloudVirtualization and the CloudVirtualization and the CloudVirtualization and the Cloud

The architecture that we discussed forms the heart and soul of Cloud

Computing.

Here is how

ElasticityElasticityElasticityElasticity

We know that the key attribute of the Cloud is Elasticity, which is the ability

to scale up and scale down on the fly. This capability is achieved only through

virtualization. Scaling up is technically adding more server VMs to an

application and scaling down is detaching the VMs from the application.

Self ServiceSelf ServiceSelf ServiceSelf Service

The next attribute is Self Service. The Hypervisor comes with an API and therequired agents to manage it remotely. This functionality can surface

through the Self Service portals that the Cloud vendor offers. So, when you

move a slider to increase the number of servers in your web tier, you are

essentially talking to the Hypervisor to action that request.

PayPayPayPay----ByByByBy----UseUseUseUse


29/55


Pay-By-Use is the next attribute of the Cloud. By leveraging the management

and monitoring capabilities of the Hypervisor, metering the usage of

resources like the CPUs, RAM and storage can be easily achieved.

Programmable InfrastructureProgrammable InfrastructureProgrammable InfrastructureProgrammable Infrastructure

Programmable Infrastructure is the last key tenet of the Cloud. We already

saw how the API wired into Hypervisors can be leveraged. Developers can

directly talk to the Hypervisor through the native APIs or Web Services

exposed by the Cloud vendors. Through this, they can take the control of the

VMs.

It is very obvious that the Cloud is heavily relying on virtualization andefficient Hypervisors to achieve its goal.

Dissecting the CloudDissecting the CloudDissecting the CloudDissecting the Cloud

Now that we know how Virtualization forms the core of the Cloud, lets me

put things in perspective. Lets see what actually goes inside the Cloud.

Geographic locationGeographic locationGeographic locationGeographic location

We start deciding where to physically run our application. Most of the Cloud

providers give you an option to host your application at a specific location.

Depending on the customer base and the expected user location, you can

choose a location. This will ensure that all your components like storage,

compute and database services are hosted within the same data center. This

will reduce the latency and makes the application more responsive.


30/55


Geographically spread Cloud data centersGeographically spread Cloud data centersGeographically spread Cloud data centersGeographically spread Cloud data centers

Data CenterData CenterData CenterData Center

Though you do not have a direct choice in this, your app will be deployed at a

data center physically located at a place that you have chosen. These datacenters typically run thousands of powerful servers that offer a lot of storage

and computing power.

ServerServerServerServer

You never know which physical server is responsible for running your code

and the application. In most of the cases, the app that you deployed may be

powered by more than one server running within the same data center. You

cannot assume that the same physical server will run the next instances of

A Cloud data center runs hundreds of servers


31/55


your app. Servers are treated as a commodity resource to host the VMs.

There is no affinity between a VM and a physical server. Each server in the

data center is optimally utilized at any given point.

Each serveEach serveEach serveEach server runs the Hypervisor and the VM(s)r runs the Hypervisor and the VM(s)r runs the Hypervisor and the VM(s)r runs the Hypervisor and the VM(s)

Virtual MachineVirtual MachineVirtual MachineVirtual Machine

This is the layer that you will directly interact with. In Platform as a Service

(PaaS), you may not realize that you are dealing with a VM but in reality most

of the Cloud implementations will host your code or app on a VM. VMs are

essential to respect the 4 tenets of the Cloud. Your application runs on a VM

that is managed by the Hypervisor running across all the servers. These VMs

are moved across servers based on the server utilization. There is no

guarantee that the VM that you launch will run on the same physical server.

There will be a load balancer which will ensure that your applications are

scalable by exploiting the power of all the VMs associated with your

application.


32/55


Under the hood ofUnder the hood ofUnder the hood ofUnder the hood of a servera servera servera server


33/55



Introducing Amazon Web ServicesIntroducing Amazon Web ServicesIntroducing Amazon Web ServicesIntroducing Amazon Web Services

Overview of Amazon Web ServicesOverview of Amazon Web ServicesOverview of Amazon Web ServicesOverview of Amazon Web Services

Amazon Web Services is one of the early and also the most successful

implementations of the Public Cloud. Many well-known online properties

leverage AWS. Amazon initially started offering a Cloud based Message

Queuing service called Amazon Simple Queue Service or SQS. They

eventually added services like Mechanical Turk, Simple Storage Service (S3),

Elastic Compute Cloud (EC2), A CDN service called CloudFront, a flexible and

distributed database service called SimpleDB. In the last few years the

number of services offered by AWS has grown significantly.

Amazon Web ServicesAmazon Web ServicesAmazon Web ServicesAmazon Web Services

Given that Amazon offers the core capabilities to run a complete web

application or a Line of Business application, it is obvious that it is


34/55


Infrastructure as a Service (IaaS). AWS is truly the platform of the platforms.

You can choose an OS, App server and the programming language of your

choice. AWS SDK and API is available for most of the popular languages

including Java, .NET, PHP, Python and Ruby.

Lets take a closer look at some of the key service offerings from Amazon

Web Services.

Amazon ElasticAmazon ElasticAmazon ElasticAmazon Elastic Compute CloudCompute CloudCompute CloudCompute Cloud

In simple terms, EC2 is hiring a server running at a remote location. These

servers are actually Virtual Machine images running on top of Amazons

powerful data centers. Amazon calls these virtualized server instances as

Amazon Machine Images or AMI. These instances come in different sizes that

you can choose from. Please refer to http://aws.amazon.com/ec2/#instance

for more details on the instance types. There are many pre-configured AMIs

that you can choose from. The typical workflow on EC2 is that you choose a

pre-configured AMI, launch that AMI, customize it by adding additional

software and by loading an app and finally, save that AMI as your custom

AMI. You can launch multiple instances of your AMI and attach them to an IP

called the Elastic IP. Because of the dynamic capability of launching multiple

instances of the same AMIs to scale up and terminating them to scale down,

it is called Elastic Compute Cloud.

Amazon Simple StorageAmazon Simple StorageAmazon Simple StorageAmazon Simple Storage ServiceServiceServiceService

Amazons Simple Storage Service or S3 is a great way to store data on the

Cloud that can be accessed by any application with access to the Internet. S3

can store any arbitrary data as objects accompanied by metadata. These

objects can be organized into buckets. Every bucket and object has a set of

permissions defined in the Access Control List (ACL). The objects stored in

S3 can be anything from a document, a media file, serialized objects or even


35/55


Virtual Machine images. Each object can be 5TB in size while the metadata

can be up to 2KB. All the objects can be accessed using simple REST or SOAP

calls. This makes S3 an ideal storage solution to centrally store and retrieve

data across multiple clients. Some tools let you treat S3 a virtual file system

to provide persistence storage capabilities for backup and archiving

scenarios.

AmazonAmazonAmazonAmazon SSSSimpleimpleimpleimple QQQQueuingueuingueuingueuing SSSServiceerviceerviceervice

SQS is the message queue on the Cloud. It supports programmatic sending

of messages via web service applications as a way to communicate over the

Internet. Message Oriented Middleware (MOM) is a popular way of ensuring

that the messages are delivered once and only once. Moving that

infrastructure to the web by yourself is expensive and hard to maintain. SQS

gives you this capability on-demand and through the pay-by-use model. SQS

is accessible through REST and SOAP based API.

AmazonAmazonAmazonAmazon CloudFrontCloudFrontCloudFrontCloudFront

When your web application is targeting the global users, it makes sense to

serve the static content through a server that is closer to the user. One of the

solutions based on this principle is called Content Delivery Network (CDN).

But this infrastructure of geographically spread servers to serve static

content can be very expensive. CloudFront is CDN as a service. Amazon is

leveraging its data center presence across the globe by serving content

through these edge locations. CloudFront works in conjunction with S3 by

replicating the buckets across multiple edge servers. Amazon charges you

only for the data that is served through CloudFront and there is no

requirement for upfront payment.

AmazonAmazonAmazonAmazon SimpleDBSimpleDBSimpleDBSimpleDB


36/55


If S3 offers storage for arbitrary binary data, SimpleDB is a flexible way to

store Name/Value pairs on the Cloud. This dramatically reduces the

overhead of maintaining a relational database continuously. SimpleDB is

accessed through REST and HTTP calls and can be easily consumed by any

client that can parse a HTTP response. Many Web 2.0 applications built using

AJAX, Flash and Silverlight can easily access data from SimpleDB.

AmazonAmazonAmazonAmazon RRRRelationalelationalelationalelational DDDDatabaseatabaseatabaseatabase SSSServerververviceiceiceice

Amazon RDS offers relational database on the Cloud. It supports the popular

MySQL and Oracle databases. When you are moving a traditional Line of

Business application to the Cloud and want to maintain high fidelity with the

existing systems, you can choose RDS. The advantage of RDS is that you do

not install, configure, manage and maintain the DB server. You only consume

it and Amazon takes care of the rest. Routine operations like patching the

server and backing up the databases are taken care and you only consume

the service. RDS is priced on Pay-as-you-go model and there is no upfront

investment required. It is accessible through the REST and SOAP based API.

Amazon Virtual Private CloudAmazon Virtual Private CloudAmazon Virtual Private CloudAmazon Virtual Private Cloud

Amazon VPC is a secure way of connecting companys existing IT

infrastructure to the AWS cloud. Amazon VPC enables enterprises to connect

their existing infrastructure to a set of isolated AWS compute resources via a

Virtual Private Network (VPN) connection, and to extend their existing

management capabilities such as security services, firewalls, and intrusion

detection systems to include their AWS resources.

AWSAWSAWSAWS ScenariosScenariosScenariosScenarios

Scalable Web ApplicationScalable Web ApplicationScalable Web ApplicationScalable Web Application


37/55


If you are an aspiring entrepreneur and want to go-live with your app without

an upfront investment, Amazon is the place to go. By running your web app

on Amazon, you can dynamically scale you application on demand and only

pay for what you use. This can be the best playground for you to determine

the server capacity needs and asses the peak traffic patterns before the

commercial launch of your web app.

Line of Business ApplicationLine of Business ApplicationLine of Business ApplicationLine of Business Application

If your enterprise has to open up an internal LOB application to its

employees and trading partners, it can extend the application to the Cloud by

leveraging a concept of AWS called Virtual Private Cloud (VPC). This is

achieving the Hybrid Cloud capabilities by partially moving an application to

the Cloud while still running the sensitive and proprietary part of the LOB

application secured behind the firewall. VPC enables organizations to

securely extend itself to the Cloud.

Data ArchivalData ArchivalData ArchivalData Archival

Data that is not very frequently accessed but may be required due to data

retention policies can be easily archived on Amazon S3. By building a simple,

searchable frontend, this data can be searched and retrieved on-demand.

Moving the data to the Cloud will ensure that is available from anywhere and

anytime.

HighHighHighHigh----Performance Computing On DemandPerformance Computing On DemandPerformance Computing On DemandPerformance Computing On Demand

For many enterprises, there is an occasional requirement of high

performance computing. Investing in high-end servers is not an optimal

solution because they may not be utilized after the task is done. With AWS,

companies can virtually hire as much computing power as they need and


38/55


pay only for what they used. This will eliminate the expensive proposition of

investing in the infrastructure.

Scalable Media DeliveryScalable Media DeliveryScalable Media DeliveryScalable Media Delivery

A TV channel might want to start delivering the recorded shows to its global

audience. Since most of the content is static, they can leverage the CDN

capabilities. Signing up with services like Akamai and LimeLight can be

expensive. Because the media content is already stored on S3, it is very easy

and cost effective to leverage Amazons CloudFront to deliver the media

content through the geographically spread edge locations.


39/55



Introduction to MicrosoftIntroduction to MicrosoftIntroduction to MicrosoftIntroduction to MicrosoftWindowsWindowsWindowsWindows AzureAzureAzureAzure

Overview of Windows Azure PlatformOverview of Windows Azure PlatformOverview of Windows Azure PlatformOverview of Windows Azure Platform

Microsoft Windows Azure Platform is a Platform as a Service offering from

Microsoft. It was announced in 2009 and became available in 2010. Since

then Microsoft has been constantly improving the platform by adding new

features.

Windows Azure Platform is aiming at becoming the preferred platform for

both, the new age web developers and enterprises. For the web developers

building scalable web applications, it offers compute, storage, and cachingalong with CDN services. It also has enterprise specific features like Active

Directory integration, virtual networking and business intelligence

capabilities.

Microsoft Windows Azure PlatformMicrosoft Windows Azure PlatformMicrosoft Windows Azure PlatformMicrosoft Windows Azure Platform


40/55


Though Windows Azure Platform is designed for the developers building

applications on the Microsoft platform, developers building applications on

Java and PHP environments can also leverage this. Microsoft is investing in

the right set of tools and plug-ins for Eclipse and other popular developer

environments.

I will first explain each of the components of Windows Azure Platform and

then walk you through the scenarios for deploying applications on this

platform.

Windows AzureWindows AzureWindows AzureWindows Azure

Windows Azure is the heart & soul of the Azure Platform. It is the OS that

runs on each and every server running in the data centers across multiple

geographic locations. It is interesting to note that Windows Azure OS is not

available as a retail OS. It is a homegrown version exclusively designed to

power Microsofts Cloud infrastructure. Windows Azure abstracts the

underlying hardware and brings an illusion that it is just one instance of OS.

Because this OS runs across multiple physical servers, there is a layer on

the top that coordinates the execution of processes. This layer is called the

Fabric. In between the Fabric and the Windows Azure OS, there are Virtual

Machines (VM) that actually run the code and the applications. As a

developer, you will only see two services at the top of this stack. They are 1)

Compute and, 2) Storage.

ComputeComputeComputeCompute

You interact with the Compute service when you deploy your applications on

Windows Azure. Applications are expected to run within one of the three

roles called Web Role, Worker Role and VM Role. Web Role is meant to host


41/55


typical ASP.NET web applications or any other CGI web applications. Worker

Role is to host long running processes that do not have any UI. Think of the

Web Role as an IIS container and the Worker Role as the Windows Services

container. Web Role and Worker Role can talk to each other in multiple

ways. The Web Role can also host WCF Services that expose a HTTP

endpoint. The code within Worker Role will run independent of the Web Role.

Through the Worker Role, you can port either .NET applications or native

COM applications to Windows Azure. Through Worker Role, Windows Azure

offers support for non-MS environments like PHP, Java and Node.js. VM

Role enables running applications within a custom Windows Server 2008 R2

image. This will enable enterprises to easily port applications that have

dependencies or 3rdparty components and legacy software.

StorageStorageStorageStorage

When you run an application, you definitely need storage to either store the

simple configuration data or more complex binary data. Windows Azure

Storage comes in three flavors. 1) Blobs, 2) Tables and, 3) Queues.

Blobs can store large binary objects like media files, documents and even

serialized objects. Table offers flexible name/value based storage. Finally,

Queues are used to deliver reliable messages between applications. Queues

are the best mechanism to communicate between Web Role and Worker

Role. The data stored in Azure Storage can be accessed through HTTP and

REST calls.

Service BusService BusService BusService Bus

This service enables seamless integration of services that run within an

organization behind a firewall with those services that are hosted on the

Cloud. It forms a secure bridge between the legacy applications and the

Cloud services. Service Bus provides secure connectivity between on-


42/55


premise and Cloud services. It can be used to register, discover and

consume services irrespective of their location. Services hosted behind

firewalls and NAT can be registered with the Service Bus and these services

can be then invoked by the Cloud Services. The Service Bus abstracts the

physical location of the service by providing a URI that can be invoked by any

potential consumer.

Access Control ServiceAccess Control ServiceAccess Control ServiceAccess Control Service

Access Control is a mechanism to secure your Cloud services and

applications. It provides a declarative way of defining rules and claims

through which callers can gain access to Cloud services. Access Control

rules can be easily and flexibly configured to cover a variety of security

needs and different identity-management infrastructures. Access Control

enables enterprises to integrate their on-premise security mechanisms like

Active Directory with the Cloud based authentication. Developers can

program Access Control through simple WCF based services.

CachingCachingCachingCaching

Caching provides an in-memory caching service for applications hosted on

Windows Azure. This avoids the disk I/O and enables applications to quickly

fetch data from a high-speed cache. Cache can store multiple types of data

including XML, Binary, Rows or Serialized CLR Objects. Web applications that

need to access read-only frequently can access the cache for better

performance. ASP.NET developers can move the session to Cache to avoid

single-point-of failure.

SQL AzureSQL AzureSQL AzureSQL Azure

SQL Azure is Microsoft SQL Server on the Cloud. Unlike Azure Storage, which

is meant for unstructured data, SQL Azure is a full-blown relational database

engine. It is based on the same DB engine of MS SQL Server and can be


43/55


queried with T-SQL. Because of its fidelity with MS SQL, on-premise

applications can quickly start consuming this service. Developers can talk to

SQL Azure using ADO.NET or ODBC API. PHP developers can consume this

through native PHP API. Through the Microsoft SQL Azure Data Sync, data

can be easily synchronized between on-premise SQL Server and SQL Azure.

This is a very powerful feature to build hubs of data on the Cloud that always

stay in sync with your local databases. For all practical purposes, SQL Azure

can be treated exactly like a DB server running in your data center without

the overhead of maintaining and managing it by your teams. Because

Microsoft is responsible for installation, maintenance and availability of the

DB service, business can only focus on manipulating and accessing data as a

service. With the Pay-as-you-go approach, there is no upfront investment

and you will only pay for what you use.

Scenarios for Microsoft Windows Azure PlatformScenarios for Microsoft Windows Azure PlatformScenarios for Microsoft Windows Azure PlatformScenarios for Microsoft Windows Azure Platform

Scalable Web ApplicationScalable Web ApplicationScalable Web ApplicationScalable Web Application

Because Windows Azure Platform is based on the familiar .NET platform,

ASP.NET developers can design and develop web applications on fairly

inexpensive machines and then deploy them on Azure. This will empower the

developers to instantly scale their web apps without worrying about the cost

and the complexity of infrastructure needs. Even PHP developers can enjoythe benefits of elasticity and pay-by-use attributes of the platform.

Compute Intensive ApplicationCompute Intensive ApplicationCompute Intensive ApplicationCompute Intensive Application

Windows Azure Platform can be used to run process intensive applications

that occasionally need high end computing resources. By leveraging the

Worker Role, developers can move code that can run across multiple


44/55


instances in parallel. The data generated by either Web Role or On-Premise

applications can be fed to the Worker Roles through Azure Storage.

Centralized Data AccessCentralized Data AccessCentralized Data AccessCentralized Data Access

When data has to be made accessible to a variety of applications running

across the browser, desktop and mobile, it makes sense to store that in a

central location. Azure Cloud based storage can be great solution for

persisting and maintaining data that can be easily consumed by desktop

applications, Silverlight, Flash and AJAX based web applications or mobile

applications. With the Pay-as-you-grow model, there is no upfront

investment and you will only pay for what you use.

Hybrid Applications (Cloud + OnHybrid Applications (Cloud + OnHybrid Applications (Cloud + OnHybrid Applications (Cloud + On----Premise)Premise)Premise)Premise)

There may be a requirement for extending a part of an application to the

Cloud or building a Cloud faade for an existing application. By utilizing the

services like Service Bus and Access Control, on-premise applications can

be seamlessly and securely extended to the Cloud. Service Bus and a

technology called Azure Direct Connect can enable the Hybrid Cloud

scenario.

CloudCloudCloudCloud Based Data HubBased Data HubBased Data HubBased Data Hub

Through SQL Azure, companies can securely build data hubs that will be

open to trading partners and mobile employees. For example, the Inventory

of a manufacturing company can be securely hosted on the Cloud that is

always in sync with the local inventory database. The Cloud based DB will be

opened up for B2B partners to directly query and place orders. SQL Azure

and the SQL Azure Data Sync will enable interesting scenarios.


45/55



IntroducingIntroducingIntroducingIntroducing Google App EngineGoogle App EngineGoogle App EngineGoogle App Engine

Google App Engine is a platform to deploy and run web applications on

Googles infrastructure. It comes with a dynamic web server with full

support for common web technologies. It offers a transactional data store for

persisting data. Developers can integrate their web application with Google

Accounts through the APIs. The biggest advantage of running web

applications on GAE is the scalability that it offers. Your web application will

be as scalable as some of the popular Google services like search.

Google App Engine currently supports Python, Java and a brand new

language from Google called Go. Java developers will be able to deploy and

run JSPs and Servlets while Python developers can use standard library.

Since GAE runs in a sandbox, not all operations are possible. For example,

opening and listening on sockets is disabled. The applications running on

GAE live in a sandbox that provides multi-tenancy and isolation across

applications.

Components of Google App EngineComponents of Google App EngineComponents of Google App EngineComponents of Google App Engine

The next logical layer is a set of APIs and Services to support the web

application developers. This layer has a persistent Datastore, User

Authentication services, Task Scheduler and Task Queue, URL Fetch, a Mail

component, MemCache and Image Manipulation. All these services are

exposed through native API bindings. For example, Java developers will be

able to use JDO/JPA to talk to the datastore.


46/55


Lets take a closer look at some of the services provided by GAE.

Java RuntimeJava RuntimeJava RuntimeJava Runtime

GAE is based on Java 6 VM and Servlet 2.5 Container. The datastore can be

accessed through the JDO/JPA API. It supports JSR 107 for MemCache API.

Mail can be accessed through javax.mail API. Javax.net.URLConnection

provides access to URLFetch service. Apart from core Java language, other

dynamic languages based on Java like JRuby and Scala.

Python RuntimePython RuntimePython RuntimePython Runtime

GAE comes with a rich set of API and tools for developing web applications

based on Python. It supports Python 2.5.2 and Python 3 is being considered

for the future releases. You can also take advantage of a wide variety of

mature libraries and frameworks for Python web application development,

such as Django. The Python environment provides rich Python APIs for the

datastore, Google Accounts, URL fetch, and email services. App Engine also

provides a simple Python web application framework called webapp to make

it easy to start building applications.

DatastoreDatastoreDatastoreDatastore

App Engine comes with a very powerful data storage that can scale

dynamically. It also features a query engine and support for transactions.

The datastore is different from traditional relational databases. The objects

stored in datastore are called Entities which are schemaless. These

entities have a set of properties that can be queried using a SQL like


47/55


grammar like GQL or Google Query Language. The datastore is strongly

consistent and supports optimistic concurrency control.

User AuthenticationUser AuthenticationUser AuthenticationUser Authentication

One of the advantages of using GAE is its integration with Google Accounts.

This empowers the developers to leverage Googles secure authentication

engine for their custom applications. While a user is signed in to the

application, the app can access the user's email address, as well as a unique

user ID. The app can also detect whether the current user is an

administrator, making it easy to implement admin-only areas of the app.

URL FetchURL FetchURL FetchURL Fetch

This service will fetch external web pages using the high bandwidth that

many other Google applications use.

MailMailMailMail

This will enable developers to programmatically send email messages from

custom web applications.

MemCacheMemCacheMemCacheMemCache

The Memcache service provides applications with a high performance in-

memory key-value cache that is accessible by multiple instances of the

application. Memcache is useful for data that does not need the persistence

and transactional features of the datastore, such as temporary data or data

copied from the datastore to the cache for high speed access.

Image ManipulationImage ManipulationImage ManipulationImage Manipulation

Through this service, developers can manipulate images. With this API, you

can resize, crop, rotate and flip images in JPEG and PNG formats.


48/55


Scheduled TasksScheduled TasksScheduled TasksScheduled Tasks

Scheduled Tasks are also called cron jobs. Other than running interactive

web applications, GAE can also schedule tasks that can be invoked at a

specific time.

To get started on Google App Engine, download the Eclipse plug-in and the

SDK.

The SDK emulates the GAE environment locally and enables you to design,

develop and test applications on your machine before finally deploying on

GAE.


49/55



IntroducingIntroducingIntroducingIntroducing OpenStackOpenStackOpenStackOpenStack

In July 2010, Rackspace, one of the IaaS players has partnered with NASA to

launch an open source cloud project called OpenStack. The key objective of

OpenStack is to create a unified platform that powers both the Private Cloud

and the Public Cloud. This will make it easy to move workloads seamlessly

across the Private Cloud and the Public Cloud. Enterprises can deploy

OpenStack within their data center and service providers can leverage it to

set up Public Cloud. Though another open source project called Eucalyptus

was started with the same mission, it did not garner much attention as

OpenStack did. OpenStack has the credibility of NASA and the track record

of Rackspace. This attracted over 20 companies including the biggies like

Intel, Dell and Citrix to join this initiative. Since its launch the list has grown

to over 120 companies. One of the recent wins for OpenStack came from HP.

HP has recently announced HP Cloud that is completely built on OpenStack.

Its definitely an indication that the industry is open to embrace OpenStack.

In October 2011, Rackspace has announced plans to hand over the

responsibility of the project to OpenStack Foundation with the intent of

making it a true industry standard for Cloud. Internap, one of the Public

Cloud providers had introduced the first commercial implementation of

OpenStack.

Unlike the commercial implementations, OpenStack is Hypervisor agnostic.

Instead of focusing on building a new Hypervisor, it is designed to run on

popular Hypervisors including Citrix XenServer, Microsoft Hyper-V, Xen,

KVM, VMware ESX and others. This enables enterprises and service

providers to setup a cloud based on their existing Hypervisors thus

protecting their investments. So, what are the key components of


50/55


OpenStack? The basic requirement for any IaaS environment is compute and

storage services. In the case of Amazon Web Services, EC2 and S3 deliver the

compute and storage services. Beyond these two core services, IaaS also

needs a service to catalog and manage the virtual machine images. Of

course, there are many other key components that make the offering more

complete and mature, but compute, storage and VM catalog manager forms

the core of an IaaS platform. OpenStacks compute service is code-named

Nova, the storage service is code-named as Swift and the catalog manager is

code-named Glance. These three form the building blocks of OpenStack.

Lets take a closer look at these services.

OpenStack Compute (Nova)

This is responsible for the provisioning of VMs, managing networking of VMs

and creating redundancy of the compute layer. It exposes API and provides

the control panel to manage the environment. Nova is designed to run on all

major Hypervisors. It also runs a fabric to orchestrate and coordinate the VM

provisioning and de-provisioning across multiple physical machines. Nova is

the foundation for large cloud deployment that spans data centers and

locations. This closely resembles the Amazon EC2 environment.

OpenStack Storage (Swift)

Swift is the object store of OpenStack that is based on Rackspace CloudFiles.It is designed to handle Petabytes of storage using the standard commodity


51/55


hardware. Swift is massively scalable and provides redundant object

storage. Objects are written to multiple physical storage devices to ensure

data integrity and redundancy. The structure of Swift is comparable to

Amazon S3 environment. The APIs are compatible with Amazon S3 API and

just by changing the end-point, existing Amazon S3 based applications can

talk to Swift.

OpenStack Image Service (Glance)

Glance provides discovery, registration and delivery services for virtual disk

images. It maintains the metadata of the VM images that can be queried to

get a catalog of existing images. It can also maintain the details of images

stored on Amazon S3. Glance supports many formats of virtual disk images

including AMI (Amazon EC2), VHD (Microsoft Hyper-V), VDI (Oracle

VirutalBox) and VMDK (VMware).


52/55



Introduction toIntroduction toIntroduction toIntroduction to Cloud FoundryCloud FoundryCloud FoundryCloud Foundry

Cloud Foundry originally started as a platform to deploy Java Spring

applications on Amazon Web Services. In April 2011, VMware acquired Cloud

Foundry and made that it into an open source, multi-language and multi-

framework PaaS offering. Cloud Foundry supports multiple languages and

multiple runtimes such as Java, Spring, Ruby, Scala and Node.js. VMware

calls this an Open PaaS as Cloud Foundry can run on anything from a

notebook PC to a Public Cloud.

Cloud Foundry as Open PaaSCloud Foundry as Open PaaSCloud Foundry as Open PaaSCloud Foundry as Open PaaS

Cloud Foundry has three dimensions to the platform. The first one is all

about the choice of frameworks while the second is choice of application

services and the final dimension is the deployment choice.

Framework ChoiceFramework ChoiceFramework ChoiceFramework Choice


53/55


Cloud Foundry supports Spring for Java, Rails and Sinatra for Ruby, Node.js

and JVM languages like Groovy, Grails and Scala. It also supports Microsoft

.NET Framework and became the first non-Microsoft platform to support

.NET. This makes Cloud Foundry one of the first Polyglot PaaS.

Application ChoiceApplication ChoiceApplication ChoiceApplication Choice

The Cloud-era developers need support of a reliable messaging system,

NoSQL databases along with relational databases. Cloud Foundry includes

support for RabbitMQ for messaging, MongoDB and Redis for NoSQL and

MySQL as the relational database. The list of supported services is growing

and recently PostgreSQL support was added to the platform.

Deployment ChoiceDeployment ChoiceDeployment ChoiceDeployment Choice

Cloud Foundry can be deployed on notebook PCs through Micro Cloud

Foundry. Micro Cloud Foundry is the complete version of Cloud Foundry

designed to run in a virtual machine on a developers PC or Mac. It can also

be deployed on Private Cloud running within an enterprise or on a Public

Cloud like Amazon Web Services. This makes Cloud Foundry an extremely

flexible PaaS.

Deploying applications onDeploying applications onDeploying applications onDeploying applications on CloudCloudCloudCloud FoundryFoundryFoundryFoundry

Developers can choose to deploy applications either through the

SpringSource Tool Suite (STS) or through the Command line Ruby Gem

called VMC.


54/55


Logical view of Cloud FoundryLogical view of Cloud FoundryLogical view of Cloud FoundryLogical view of Cloud Foundry

Messaging is the nervous system of Cloud Foundry. It is the central

communication system that enables all the components to talk to each other.

Routers handle all HTTP the traffic targeting the applications. They route

URLs to applications and also does load balancing of the traffic across

instances.

Cloud Controllers are the key components that handle packaging and staging

of the applications. They bind various services to applications. The external

REST API is exposed through them.

Health Manager monitors the health of all running applications. In case of a

failure of an application, it informs the Cloud Controllers to take action.

DEA stands for Droplet Execution Agent. Every unit of executable code in

packaged as a Droplet in Cloud Foundry. These Droplets abstracts the

underlying code and exposes a generic executable code unit. DEA is


55/55

responsible for executing the code within each Droplet. They provide the OS

and runtime environment.

SummarySummarySummarySummary

Cloud Foundry is quickly gaining ground as an Open PaaS. Many vendors are

announcing their support and bringing newer platforms and services into the

stack. It may provide tough competition to commercial PaaS vendors like

Microsoft and Google.

demystifying the cloud.pdf

Documents