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What is cloud computing? This is an introduction that I gave at MegaCOMM 2013, a conference for technical writers in Jerusalem. The talk describes how the combination of Internet access, virtualization, and open source have made computing a utility that we can turn on and off at will -- similar in some ways to electricity, water, and other utilities with which we're familiar.
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Cloud Computing:What is it?
What does it mean?Reuven M. Lerner • [email protected]
MegaCOMM • February 7th, 2013
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Who am I?
• Long-time Web developer, trainer, consultant
• Linux Journal columnist
• PhD candidate in Learning Sciences at Northwestern University
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Everyone is talking about cloud computing!
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In case you missed it:
77,300,000 results!?!5
Wow, this must be big!
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But what is cloud computing?
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About.com
Cloud computing consists of hardware and software resources made available on the Internet as managed third-party services. These services typically provide access to advanced software applications and high-end networks of server computers.
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Investopedia... resources are retrieved from the internet through web-based tools and applications, rather than a direct connection to a server. Data and software packages are stored in servers. However, cloud computing structure allows access to information as long as an electronic device has access to the web. This type of system allows employees to work remotely.
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TechTerms.com
Cloud computing refers to applications and services offered over the Internet. These services are offered from data centers all over the world, which collectively are referred to as the “cloud.” This metaphor represents the intangible, yet universal nature of the Internet.
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These are not helpful.
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NIST
... a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
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The important points
• Ubiquitous
• Convenient
• On demand
• Shared pool
• Configurable computing resources
• Rapidly provisioned and released
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This reminds me of...
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Public utilities
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Utilities
• Ubiquitous
• Convenient
• On demand
• Shared pool
• Rapidly provisioned and released
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Computing utility
• Cloud computing turns computers into a utility
• Always available
• Pay as you go
• When it’s not available, you get angry!
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Abstraction
• A core concept in computer science
• Treat many parts as if they were one whole
• Cloud computing treats entire computers, or groups of computers, as an abstraction
• Who cares how it works inside?
• Use the black box
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An old idea: Computing utility
• People and businesses don’t need computers.
• They need computing.
• So let’s provide them with a computing utility, like the water and electric company!
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Multics
• Joint project between MIT, Bell Labs, and GE (1964)
• A huge commercial failure!
• Bell Labs pulled out
• GE sold its part to Honeywell
• There were a few Multics machines in the world — last one went offline in 2000
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Unix
• Bell Labs left the Multics project in 1969
• Two of the programmers from Multics, Ken Thompson and Dennis Ritchie, created a smaller system
• They called it Unix, as a play on the “Multics” name
• Rejected the complexity of Multics
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Multiprocessing
• Multics and Unix both assumed that you could run more than one program at a time
• “Multiprocessing” is really an illusion, of course
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What is a program?
Code
Data
You are here
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Multiprocessing
Code
Data
PointerCode
Data
PointerCode
Data
Pointer
Currentprocess
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Multiprocessing
Code
Data
PointerCode
Data
PointerCode
Data
Pointer
Currentprocess
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Multiprocessing
Code
Data
PointerCode
Data
PointerCode
Data
Pointer
Currentprocess
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Multiprocessing
Code
Data
PointerCode
Data
PointerCode
Data
Pointer
Currentprocess
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Linux
• Open source clone of Unix
• Can be copied, used, distributed freely
• You don’t need to ask anyone before creating a new copy
• Oh, and it’s really robust, too
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Virtualization!
• A program on my computer is code + data
• What if the code is a program that pretends to be a full computer?
• Yes, my computer will run a program with a virtual machine on it
• To my computer, it’s one program — but to me, I effectively have a second computer
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Code
Data
Code
Data
Code
Data
Code
Data
Code
Data
Code
Data
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Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
Co
Dat
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But where?
• On your computer (VMWare, Virtualbox)
• On a hosting provider’s server
• On Amazon
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Amazon?!?
• I’ve bought goods from Amazon from the beginning
• (I even have cups that they sent all of their original customers, thanking them for supporting “Earth’s biggest bookstore.”)
• Amazon needed lots of servers for their growing business, to satisfy people like me
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Amazon
• Amazon doesn’t break out income, but...
• “Amazon Cloud Revenue Could Exceed $500 Million In 2010: Report” (2010)
• “Don’t look now, but AWS might be a billion-dollar biz” (2011)
• “Amazon's AWS: $3.8 billion revenue in 2013, says analyst” (2013)
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Amazon’s solution
• Don’t use servers directly
• Rather, put many virtual machines on a physical computer
• When the load rises, launch more virtual machines — and when it falls, kill them off
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AWS
• Amazon Web Services began as a way to query Amazon’s catalog
• Today, it’s many pay-by-the-hour services
• EC2 — elastic computing cluster — lets you create and launch Linux boxes via a Web console or even a program!
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Sounds like a utility
• The combination of Linux + virtualization + Internet access made it possible to realize the dream that Multics had years ago
• You need computing power? Launch it.
• You’re done with it? Power it down.
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NIST’s criteria
• Ubiquitous
• Convenient
• On demand
• Shared pool
• Configurable computing resources
• Rapidly provisioned and released
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Why do this?
• IT staff costs basically disappear
• You pay only for the servers you need
• If demand is variable, you can add and remove servers dynamically
• Configure your virtual server once — and deploy it hundreds or thousands of times
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Automation
• It gets even better than this: You can create and destroy EC2 instances via programs
• You can be a web hosting company without owning or renting any servers!
• When a customer signs up, just launch a new EC2 instance
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What about storage?
• You don’t want to store things on computers that can go up and down
• Amazon offers S3 (simple storage service) lets you store any number of files, of just about any size
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EC2 isn’t alone
• Other companies also offer virtual servers
• Some companies, such as Rackspace, also make it possible to spin them up and down on demand
• Even so, Amazon is the 900-lb gorilla in this space
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The car analogy
• Buy — big up-front costs, lots of maintenance, you control 100% of its use
• Lease — much smaller up-front costs, someone else handles maintenance, higher monthly costs
• Rent — Get a car for the days or weeks you need. No up-front costs, but higher daily costs
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Renting cars a la ZipCar or Car2Go• You can rent virtual servers from Amazon,
so long as they have the space
• (And they’ll basically always have the space)
• Let them worry about maintenance, hosting, electricity, etc.
• It’s a shared resource, so performance isn’t as good as a dedicated server
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IaaS
• EC2 is an example of Infrastructure as a Service
• You get Linux boxes, but not much more
• You still need to configure them and work with them
• And do you really want to configure (or upgrade) hundreds of servers?
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• Two software frameworks that let you describe how servers should be configured
• Then you say, “Puppet, please configure these 1,000 Rackspace servers according to the following criteria.”
• Want to change your configuration? Adjust it once, and Puppet/Chef will do the job
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PaaS
• Sometimes, you want to rent more than a bare Linux server
• If you want to launch Web applications, it would be great if EC2 handled all of that automatically
• EC2 doesn’t, but PaaS — Platform as a Service — providers do!
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PaaS
• PaaS for Web apps: Copy your files to the server, and it handles the rest
• Heroku
• Google App Engine
• EngineYard
• AWS Elastic Beanstalk
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PaaS, good and bad
• Good:
• Almost no IT staff
• Trivially easy to add/remove servers
• Security
• Bad:
• Performance
• Price, compared with a server
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Think apps, not servers
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A whole ecosystem
• Cloud consultants!
• Autoscaling companies
• Third-party add-ons for cloud servers
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Add-ons
• Storage
• Message queues
• Monitoring
• Logging
• Payments
• Video/audio encoding
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Private cloud
• What if you don’t like the idea of paying Amazon for their servers, but you do want to enjoy that flexibility?
• You can create a private cloud!
• CloudFoundry is an open-source VMWare product that lets you do just that
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Standards
• OpenStack (IaaS), CloudFoundry (PaaS)
• If you hate your cloud hosting provider, but they use a common infrastructure, you can switch to someone else
• Both are open-source initiatives
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Databases
• Heroku uses PostgreSQL
• (a great database, by the way)
• They run it on EC2 for clients’ Web apps
• As of recently, they also offer it as a separate package — database as a service!
• Backups, followers, health checks, snapshots
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Database as a service
• Many databases are offering this, from open source to proprietary
• SQL, NoSQL, Hadoop
• Often slower, but someone else installs, maintains, and tunes the database
• Enjoy a database without a DBA!
• Sometimes, make queries using a GUI
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SaaS
• Of coure, there’s also Software as a Service
• Lots of examples of these
• You probably even use some of them!
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Well-known SaaS• Gmail (e-mail)
• Google Docs (office applications)
• Salesforce (CRM)
• Dropbox (file sync)
• Mozy (backups)
• Wordpress, Blogger (blogging)
• Harvest, invoice4u (invoicing)
• Facebook (wasting time)
• Twitter (wsting tme #wowcool)
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API
• Make your SaaS app available to programs, not just computers
• Browsers speak HTTP + HTML
• APIs typically speak HTTP + JSON
• Programmers can then access your SaaS product even without a browser, creating an app using your platform!
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Trust
• Do you trust your provider not to steal your data?
• Do you feel comfortable putting your data on a server that you can’t secure yourself?
• More and more, people are saying “yes” — but figure
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Downtime
• Amazon EC2 goes down
• Typically, only one “region”
• You have to build this into your application
• Netflix CrashMonkey
• More devops
• You need to plan, or prepare to go down
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Going bust
• Will the hosting provider be around next year?
• Many are startups — most startups go out of business
• And sometimes, the platform provider competes with addon providers (e.g., Zencoder vs. Amazon)
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Conclusion
• Cloud computing is a big buzzword — but also a clear trend
• Concentrate on your apps and your business, not your IT infrastructure!
• The cloud isn’t a panacea, but it has lots of benefits — give it a shot!
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Thanks!(Any questions?)
[email protected]://www.lerner.co.il/
054-496-8405“reuvenlerner” on Skype
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