Cloud Computing

Dave Elliman

19/04/23G53ELC1

Source: NY Times (6/14/2006)

The datacenter is the computer!

Two Key Enterprise Technologiesfor the Cloud

Message Oriented Middleware (MOM)

Allows load sharing and loose coupling and is robust to server failure.

Virtualization:

The ability to run multiple operating systems on a single physical system and share the underlying hardware resources

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A definition

Cloud Computing:

“The provisioning of services in a timely (near instant), on-demand manner, to allow the scaling up and down of resources”

Requirements…

IApplications are International and expect users from anywhere in the world

Applications access huge (Petabyte) databases

Applications expect to download content rapidly anywhere

Applications need to scale with user load without degrading response

Applications need to be available 24/7 365 days a year

Applications need to be secure and well defended

Companies wish to pay only for bandwidth and server time used

What’s a Petabyte?

1024 Bytes = 1 Kilobyte

1024 Kilobytes = 1 Megabyte

1024 Megabyte = 1 GigaByte

1024 Gibabytes = 1 Terabyte

1024 Terabyte = 1 Petabyte

Exercise for the student: Write down the number of bytes in a Petabyte as a number

Petrabyte applications are not unusual nowadays

Google believed to processes 30 PB a day

eBay has 7 PB of user data

Facebook has 36 PB of user data

A million times cheaper since 1980

The communications growth rate is also amazing

Why not just set up your own servers?

Lot’s of reasons…

Will give an example…

Suppose you are Forbes.com

You offer on-line real time stock market data

Why pay for capacity weekends, overnight?

9 AM - 5 PM,M-F

ALL OTHER TIMES

Rate of Server

Accesses

Forbes' Solution

Host the web site in Amazon's EC2 Elastic Compute Cloud

Provision new servers every day, and deprovision them every night

Pay just $0.10* per server per hour * more for higher capacity servers

Let Amazon worry about the hardware, the scaling, the local (edge) delivery, the security, the availability, and the backup(?).

Cloud computing takes virtualization to the next step

You don’t have to own the hardware

You “rent” it as needed from a cloud

There are public cloudse.g. Amazon EC2, and now many others

(Microsoft Azure, IBM, Sun, and others ...)

A company can create a private cloudWith more control over security, etc.

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Lower Cost

No need to pay for infrastructure up front

No need for expensive support staff

only pay for what you use

Great for start-ups – may even be free

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More Agile

It used to take 3 months to set up an application on a cluster of servers

Takes half an hour in the cloud

Scale up or down (elasticity)

OK It’s a good idea. How does it work?

We already saw how to set up a RESTful web service on the Amazon cloud. It took five minutes.

Very easy to serve static web pages in this way

Quite simple to store and access data in the cloud as files or databases

More tricky to set up large scalable applications, but this is where really big pay-offs are possible.

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How Cloud Computing Works

Various providers let you create virtual servers Set up an account, perhaps just with a credit card

You create virtual servers ("virtualization") Choose the OS and software each "instance" will have It will run on a large server farm located somewhere You can instantiate more on a few minutes' notice You can shut down instances in a minute or so

They send you a bill for the processor time and comms bandwidth that you use

Virtualisation is the key technology

We will look at how this is done in another lecture

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Worries?

How do I pick a provider?

Is my data secure?

Do I have any control over where my data is moved to?

How can I be sure the provider will live up to all those promises?

(footnote)How come Amazon?

It arose out of efforts to manage Amazon’s own services (Each time you get a page from Amazon, over a hundred servers

are involved) See reference Amazon Architecture on ELC web page

They got so good at it that they launched Amazon Web Services (AWS) as a product

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Cloud Computing Status

Seems to be rapidly becoming a mainstream practice

Numerous providers Amazon EC2 imitators ... Just about every major industry name

• IBM, Sun, Microsoft, ...

Major buzz at industry meetings

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The revolution

Rent it instead of build it – pay for what you use

Rely on the experts to solve all those worries..

There is a major revolution underway in how we manage hardware Use many servers with virtualization Applications organized with MOM

Data cached close to delivery point

Deployment and monitoring are in-house functions

Any comments/Questions