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Cloud computing explained (educause quarterly) | educause

  1. 1. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Location: Home » Resources » EDUCAUSE Quarterly (EQ) » EQ Archives » EQ Volume 33 (2010) » Volume 33, Number 2, 2010 » Cloud Computing Explained Cloud Computing Explained By Rosalyn Metz The NIST definition of cloud computing is concise and uses industry-standard terms. Exploring the five characteristics, three service models, and four deployment models for the cloud in the NIST definition clari Examples of cloud-based technologies explained in this article promote a better understanding of the cloud. The more informed IT departments are about the cloud, the better their position when making decisions about deploying, de maintaining systems in the cloud. While many talk about the cloud, few actually understand it. Three organizations definitions come to the forefront when defining th Forrester, and the National Institutes of Standards and Technology (NIST). Although both Gartner1 and Forrester 2 provide definitio the NIST definition 3 is concise and uses industry-standard terms.4 This article takes an in-depth look at the NIST definition of cloud computing. Each of the NIST definitions points is defined in grea of cloud-based technologies will help the reader gain a better understanding of the cloud. NIST defines cloud computing as: ...a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service This cloud model promotes availability and is composed of five essential characteristics, three service models, and four dep The remainder of this article discusses these five characteristics, three service models, and four deployment models. Five Characteristics of the Cloud When people think of the cloud, they often think of software as a service (SaaS). However, the service used to supply technology technology. The following five characteristics are how NIST describes cloud computing. Characteristic: On-Demand Self-Service When an institution develops or deploys a new application, they first must jump through a number of hoops. For example, if an ins would like to install the learning management system Moodle, they might have to order a server, wait for the vendor to ship it, inst center, provision an IP address for the server, set up the DNS for the new IP address, install the operating system, etc. While virtualization tools have improved this workflow dramatically, the process can still be cumbersome. With cloud-based servic can be eliminated. Interaction with the service provider is minimized, and with a few clicks of a button, an application can be up a minutes. In the example below, I use the cloud-based service Heroku to deploy a basic blog application. Prior to creating the video, I install Herokus Ruby Gems, and Git on my computer and developed the application. Once these few simple set-up steps were accompl application into Herokus cloud took a matter of minutes. Page 1 of 9
  2. 2. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Characteristic: Resource Pooling With current systems and data centers, IT departments often get stuck in a silo of their own creation. Institutions rarely share com they do, it is cumbersome to create and manage workflows that utilize these shared resources. With the cloud, multi-tenancy rules. Users of the cloud can provision computing resources based on their needs, and then destroy them back to the shared pool once their needs are met. Additionally, users can share resources amongst themselves. For exampl developed a new piece of software and would like to share it with other institutions, they can create a template for that system in other institutions to use that template as they see fit. This example demonstrates Amazons Elastic Compute Cloud, or EC2. This service allows IT departments to choose from a share Machine Images (AMIs) and start up a server with a few clicks. AMIs offer users of Amazon EC2 a quick and easy way to set up with little to no intervention from channels one might normally need to go through. Page 2 of 9
  3. 3. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Characteristic: Rapid Elasticity Systems change constantly. To create the best experience for users, IT departments often must scale or update systems to meet or upgrading a system currently in production can be cumbersome and resource intensive for an IT department. The cloud provides ways of rapidly scaling to meet user demand. If a system requires more computing resources, an IT departme technology to meet those demands. For IT departments that use the cloud, it seems as if they have an endless supply of computin In the video below, I use Suchi Softwares S3Fox Organizer, a Firefox add-on, to access Amazon Web Services Simple Storage S users to upload files to Amazons servers and access those files through Amazon web addresses or API calls. S3 plug-ins are ava software WordPress and the web-based project management application Redmine. In addition to its use within applications, S3 is files. A number of scripts, 6 add-ons,7 and plug-ins8 help you back up your files on any type of server to Amazon S3. Characteristic: Broad Network Access Traditionally, software like Microsoft Word or PowerPoint has been offered as client-based software. Users have to install software upgrade systems to handle the programs. If youre away from your computer, you may not have access to the software, which can Today, much of the software we use is available over the Internet. Many people believe that having a resource available via the In characteristic of the cloud, but it is just one of the five characteristics. In the example here I demonstrate Google Docs, a web-based document creator and editor. Google Docs is a slimmed down vers which also has a web-based version known as Microsoft Office Web Apps 2010. Both products allow you to access and edit files an Internet connection, eliminating the need for access to a particular computer to edit documents. Page 3 of 9
  4. 4. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Characteristic: Measured Service To monitor network, server, and application usage, IT departments employ many different monitoring tools and reporting systems. allows both cloud providers and IT departments to monitor usage. Cloud providers charge IT departments based on their use of c the other hand, IT departments can use these metering (or measured) services to scale resources up and down based on informa these particular tools. The following demonstration discusses a bill from an Amazon Web Services account. In addition to this bill, I will also briefly discu Services CloudWatch, a monitoring tool that not only allows you to monitor your system but also, in conjunction with other service AWS-based system. Information on Amazons pricing schema for different services, including CloudWatch, can be found on the A website. Three Service Models for the Cloud The three types of cloud-based services are software as a service (SaaS), platform as a service (PaaS), and infrastructure as a s Remember that although computing resources may be delivered through one of these three models, it doesnt mean "cloud" provis servers are also IaaS, but virtual private servers do not possess the five characteristics of the cloud. Page 4 of 9
  5. 5. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Service Model: Cloud Software as a Service SaaS is common in the IT community. Usually software companies that provide such SaaS host their software themselves, and th maintain it for their customers. Cloud SaaS combines this hosting practice with the five characteristics of the cloud described abov the cloud is often easy to use and requires little intervention from the user to get the service up and running. In this example I once again discuss Google Docs. Similar cloud-based SaaS applications include Microsoft Web Apps 2010 and Service Model: Cloud Platform as a Service "In computing, a platform describes some sort of hardware architecture and software framework (including application frameworks run."9 A common platform in computing is the LAMP stack, or the Linux, Apache, MySQL, and PHP stack. Cloud PaaS supplies these familiar platform stacks to users, without the need for them to maintain the underlying hardware or upg software. This next example discusses Heroku, a Ruby on Rails cloud platform. Other cloud platform providers include Google Ap supports Java and Python, and Engine Yard, which supports Ruby on Rails. Page 5 of 9
  6. 6. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Service Model: Cloud Infrastructure as a Service When people think about infrastructure, if they consider it at all, they think of servers, wires, cooling systems, and all the other thin todays data centers. But when infrastructure is purchased through the cloud, none of these components are necessary; instead, u infrastructure only need to concern themselves with developing platforms and software. In the following video, I discuss Rackspace, a provider of cloud-based infrastructure as a service. Competitors to Rackspace inclu Services and GoGrid. Four Deployment Models for the Cloud Just as there are multiple ways to deploy a system within your data center, there are multiple ways to deploy a system in the cloud models described in the NIST definition of cloud computing are public cloud, community cloud, private cloud, and hybrid cloud. Wh models and the examples used have associated problems and issues (security, feasibility, etc.), this article does not cover them. Deployment Model: Public Cloud A public cloud is a cloud made available to the general public for use and is the most common type of cloud. Users of a public clo cloud provider and make payments based on the providers pricing schema. Examples include Amazon Web Services, Google app cloud-based services. Page 6 of 9
  7. 7. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Deployment Model: Community Cloud A community cloud is a cloud made available to a certain group or association. For example, a consortium of schools might decide cloud. Payments for use of the cloud might be made via dues to the consortium or through some other equitable pricing schema. Deployment Model: Private Cloud A private cloud is a cloud made available at only one particular institution. If an institution chooses to create its own private cloud, charge-back pricing schema for the different departments that use the institutions cloud. This would allow the different departmen IT resources they need, while at the same time allowing an IT department to create a sustainable support model. Page 7 of 9
  8. 8. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Deployment Model: Hybrid Cloud A hybrid cloud combines two or more of the other cloud deployment models. Perhaps part of the system lives inside a community remainder lives in a private cloud. Another way of doing this is through cloud bursting, which occurs when your system or service maintained in just your private cloud, so you allow the system to spill over into, say, a public cloud. Eucalyptus software, for exam departments to deliver their own private cloud and burst into Amazons cloud if they need to scale beyond what their private cloud Conclusion Cloud computing is complex (see Further Resources). While many people have concerns about its current uses, there is no doub way we provide systems and services. The more informed IT departments are about the cloud, the better the position they will be decisions about deploying, developing, and maintaining systems in the cloud. Page 8 of 9
  9. 9. Cloud Computing Explained (EDUCAUSE Quarterly) | EDUCAUSE 5/5/11 4:08 PM Endnotes 1. Daryl C. Plummer, Thomas J. Bittman, Tom Austin, David W. Cearley, and David Mitchell Smith, "Cloud Computing: Defining and De Phenomenon," Gartner, June 17, 2008. 2. Frank E. Gillett with Eric G. Brown, James Staten, and Christina Lee, "Future View: The New Tech Ecosystems Of Cloud, Cloud Ser Computing: Understanding, Segmenting, and Competing in the Next Computer Revolution," Forrester Research, August 28, 2008. 3. "Cloud Computing," National Institute of Standards, Computer Security Division, Computer Security Resource Center, May 11, 2009 4. Dmitry Sotnikov, "Cloud Definitions: NIST, Gartner, Forrester,", August 4, 2009. 5. Peter Mell and Tim Grance, "The NIST Definition of Cloud Computing ," ver. 15, National Institute of Standards and Technology, In Laboratory, October 7, 2009. 6. Eric Nagel, "FTP or Amazon S3 Server Backup PHP Script," blog entry May 8, 2009. 7. S3, Google Chrome Extensions, January 22, 2010. 8. Adam Greene, "S3_Rake_Tasks," GitHub, May 5, 2008. 9. This definition of computing platform comes from Wikipedia. © 2010 Rosalyn Metz. The text of this article is licensed under the The text of this article is licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.. Rosalyn Metz Systems Administrator for Curricular Support Wheaton College Cloud Computing | Cloud Computing Policy | Cloud Services | Community Cloud Computing | IaaS | private cloud | public cloud | SaaS Login or register to post comments 9037 reads Bookmark/Search this page with: Excellent summary and demonstration! Submitted by A. Michael Berman (California State University, Channel Islands) on January 7, 2011 - 5:03pm. I was looking for an article that I refer people to that would explain the basic cloud models and terminology - this article does a n with the bonus of some simple and clear demonstrations of what it looks like to provision cloud services. Good job Rosalyn! Login or register to post comments Page 9 of 9