The emergence of very large “data farms” — specialized data centers that host thousands of servers — has created a surplus of computing resources that has come to be called the cloud. Growing out of research in grid computing, cloud computing transforms once-expensive resources like disk storage and processing cycles into a readily available, cheap commodity. Development platforms layered onto the cloud infrastructure enable thin-client, web-based applications for image editing, word processing, social networking, and media creation. Many of us use the cloud, or cloud-based applications, without even being aware of it. Advances in computer science to ensure redundancy and protection from natural disasters have led to data being shared across many different hosting facilities. Improved infrastructure has made the cloud robust and reliable; as usage grows, the cloud is fundamentally changing our notions of computing and communication.
Overview
The cloud is the term for networked computers that distribute processing power, applications, and large systems among many machines. Applications like Flickr, Google, YouTube, and many others use the cloud as their platform, in the way that programs on a desktop computer use that single computer as a platform. Cloud-based applications do not run on a single computer; instead they are spread over a distributed cluster, using storage space and computing resources from many available machines as needed. “The cloud” denotes any group of computers used in this way; it is not tied to a particular location or owner, though many companies have proprietary clouds. “Amazon’s cloud,” for instance, refers to the computers used to power Amazon.com; the capacity of those servers has been harnessed as the Elastic Compute Cloud (EC2) and can be leased from Amazon for a variety of purposes.
Cloud computing services are grouped into three types. Most people are familiar with the first type: applications that serve a single function, such as Gmail (http://gmail.com) or Quicken Online (http://quicken.intuit.com/online-banking-finances.jsp), that are generally accessed through a web browser and that use the cloud for processing power and data storage. The second group of services offer the infrastructure on which such applications are built and run, along with the computing power to deliver them. Examples include Google App Engine (http://code.google.com/appengine/), which allows developers to create and host tailored programs using Google’s infrastructure; Heroku (http://heroku.com), which does the same for applications developed in Ruby on Rails; and Joyent (http://joyent.com), which hosts and scales applications in a variety of languages. The final set of cloud services are those that offer sheer computing resources without a development platform layer, like Amazon’s Elastic Compute Cloud (http://aws.amazon.com/ec2/) or the GoGrid (http://www.gogrid.com).
Cloud computing makes it possible for almost anyone to deploy tools that can scale on demand to serve as many users as desired. To the end user, the cloud is invisible; the technology that supports the applications doesn’t matter — the fact that the applications are always available is key. Data storage is cheap in these environments — pennies per gigabyte — so cheap that it is often provided in surprising quantities for free.
The cloud does have certain drawbacks. Unlike traditional software packages that can be installed on a local computer, backed up, and are available as long as the operating system supports them, cloud- based applications are services offered by companies and service providers in real time. Entrusting your work and data to the cloud is also a commitment of trust that the service provider will continue to be there, even in face of changing market and other conditions. Nonetheless, the economics of cloud computing are increasingly compelling. For many institutions, cloud computing offers a cost-effective solution to the problem of how to provide services, data storage, and computing power to a growing number of Internet users without investing capital in physical machines that need to be maintained and upgraded on-site.
Relevance for Teaching, Learning, Research, or Creative Expression
The emergence of cloud-based applications is causing a shift in the way we think about how we use software and store our files. The idea of data storage as something that can be separated from an individual computer is not unusual, but now it is becoming common to consider applications in the same light. Instead of locking files and software inside a single computer, we are gradually moving both the products of our work and the tools we use to accomplish it into the cloud. Once there, applications and data are both accessible from any computer, using tools that are free or very inexpensive. Because they live on the network, applications in the cloud make it easy to share documents, collaboratively edit, and effectively manage versions.
Educational institutions are beginning to take advantage of ready-made applications hosted on a dynamic, ever-expanding cloud that enable end users to perform tasks that have traditionally required site licensing, installation, and maintenance of individual software packages. Email, word processing, spreadsheets, presentations, collaboration, media editing, and more can all be done inside a web browser, while the software and files are housed in the cloud. In addition to productivity applications, services like Flickr (http://www.flickr.com), YouTube (http://www.youtube.com), and Blogger (http://www.blogger.com), as well as a host of other browser-based applications, comprise a set of increasingly powerful cloud-based tools for almost any task a user might need to do.
Cloud-based applications can handle photo and video editing (see http://www.splashup.com for photos and http://www.jaycut.com for videos, to name just two examples) or publish presentations and slide shows (see http://www.slideshare.net or http://www.sliderocket.com). Further, it is very easy to share content created with these tools, both in terms of collaborating on its creation and distributing the finished work. Applications like those listed here can provide students and teachers with free or low-cost alternatives to expensive, proprietary productivity tools. Browser-based, thin-client applications are accessible with a variety of computer and even mobile platforms, making these tools available anywhere the Internet can be accessed. The shared infrastructure approaches embedded in the cloud computing concept offer considerable potential for large scale experiments and research that can make use of untapped processing power.
We are just beginning to see direct applications for teaching and learning other than the simple availability of platform-independent tools and scalable data storage. This set of technologies has clear potential to distribute applications across a wider set of devices and greatly reduce the overall cost of computing. The support for group work and collaboration at a distance embedded in many cloud- based applications could be a benefit applicable to many learning situations.
Already, cloud-based applications are being used in the K-12 sector to provide virtual computers to students and staff without requiring each person to own the latest laptop or desktop machine; a handful of basic machines, provided they can access the Internet and support a web browser, are all that is needed for access to virtually unlimited data storage and programs of all kinds.
- Sciences. Science Clouds, a project that aims to provide cloud computing resources to members of the science community for limited amounts of time in support of specific projects, launched its first cloud in early 2008. Scientists may request time on the clouds in exchange for a short write- up of their project.
- Meteorology. Applications that combine a desktop interface with the data storage and computing power available in the cloud make powerful tools, once only available at large computing centers, available to anyone. One such example, Earthbrowser (http://www.earthbrowser.com), creates an interactive map populated with weather, geological, and other data; the engine that drives it lives in the cloud.
- Media Studies. Using cloud-based applications like YouTube, a media culture course at Pitzer College in California tracks emerging up-to-the-moment social trends through real-time news clips and user-created content posted there. Similarly, courses at Onondaga Community College in Syracuse, NY use YouTube and other cloud-based applications to host media that can- not be hosted using resources on campus.
Examples of Cloud Computing
The following links provide examples of cloud computing applications.
Cloud Computing Testbed
http://www.cs.illinois.edu/news/articles.php?id=2008Jul29-352
The Cloud Computing Testbed (CCT) is a research effort at the University of Illinois at Urbana-Champaign to explore ways to provide system- level support for data-intensive computing using cloud computing approaches.
Into the Cloud: Uur 5 favorite Online Storage Services
http://www.readwriteweb.com/archives/free_online_storage_services.php
(Frederic Lardinois, ReadWriteWeb, 28 September 2008.) This blog post describes five services that provide large-scale online file storage.
Open Science Grid
http://www.news.wisc.edu/12927
The University of Wisconsin-Madison and several partner schools are working on a project funded by the National Science Foundation and the Department of Energy to develop and expand a national Open Science Grid to provide computing power and data storage to solve large, data-intensive challenges in science.
Parallel Computing with Mathematica 7
http://www.wolfram.com/news/m7hpc.html
The November 2008 release of Mathematica 7 includes a tool to create a parallel computing grid using any set of computers.
Virtual Computing Lab at North Carolina State University
http://vcl.ncsu.edu/ North Carolina State University offers an online system for requesting and reserving a virtual computer, complete with any of a number of applications, that can be accessed from anywhere.
For Further Reading
The following articles and resources are recommended for those who wish to learn more about cloud computing.
Cloud Computing Expo: Introducing the Cloud Pyramid
http://cloudcomputing.sys-con.com/node/609938
(Michael Sheehan, Cloud Computing Journal, 21 August 2008.) This article illustrates a pyramid model for thinking about the types of services cloud computing enables.
How Cloud Computing is Changing the World http://www.businessweek.com/technology/content/aug2008/tc2008082_445669.htm
(Rachael King, BusinessWeek, 4 August 2008.) This article describes a perceived shift in the way we think about computing as more companies begin to use cloud-based applications for communications and productivity tasks.
The Cloudworker’s Creed
http://www.ribbonfarm.com/2008/10/23/the-cloudworkers-creed/
(Venkatesh Rao, Ribbonfarm.Com, 23 October 2008.) This blog post introduces the concept of a cloudworker, the information professional of tomorrow.
The Tower and the Cloud: an EDUCAUSE eBook
http://www.educause.edu/thetowerandthecloud/133998
(Richard N. Katz, ed., EDUCAUSE, 2008.) This book, freely available as a PDF document, includes chapters by leading educators and technologists on all aspects of cloud computing and education, including accountability, implementation, social networking, and scholarship.
Use of Cloud Computing Applications and Services
http://www.pewinternet.org/PPF/r/262/report_display.asp
(John Horrigan, Pew Internet & American Life Project, 12 September 2008.) This data memo reports on the number of Internet users who are making use of cloud-based applications and services and reviews their expressed preferences.
Web 2.0 and Cloud Computing
http://radar.oreilly.com/2008/10/web-20-and- cloud-computing.html#definitions
(Tim O’Reilly, O’Reilly Radar, 26 October 2008.) This blog post describes three types of cloud computing and considers the impact of each on business.
Delicious: Cloud Computing
http://delicious.com/tag/hz09+cloudcomputing
(Tagged by Horizon Advisory Board and friends, 2008.) Follow this link to find resources tagged for this topic and this edition of the Horizon Report, including the ones listed here. To add to this list, simply tag resources with “hz09” and “cloudcomputing” when you save them to Delicious.
Posted by NMC on January 18, 2009
Tags: Chapters


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