Cloud computing
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Cloud computing is 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. It allows users to access technology-based services from anywhere without purchasing software licenses or hardware. Some key characteristics of cloud computing include resources being remotely hosted, services being available from anywhere via the internet, and resources being provided on a utility computing basis where users pay for only what they use.
Cloud computing
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- 2. • Cloud Computing is a general term used to describe a new class of network based computing that takes place over the Internet, – basically a step on from Utility Computing – a collection/group of integrated and networked hardware, software and Internet infrastructure (called a platform). – Using the Internet for communication and transport provides hardware, software and networking services to clients • These platforms hide the complexity and details of the underlying infrastructure from users and applications by providing very simple graphical interface or API (Applications Programming Interface). 2
- 3. • Shared pool of configurable computing resources • On-demand network access • Provisioned by the Service Provider 3
- 4. • Cloud computing is an umbrella term used to refer to Internet based development and services • A number of characteristics define cloud data, applications services and infrastructure: – Remotely hosted: Services or data are hosted on remote infrastructure. – Ubiquitous: Services or data are available from anywhere. – Commodified: The result is a utility computing model similar to traditional that of traditional utilities, like gas and electricity - you pay for what you would want! 4
- 5. • Cloud are transparent to users and applications, they can be built in multiple ways – branded products, proprietary open source, hardware or software, or just off-the-shelf PCs. • In general, they are built on clusters of PC servers and off-the-shelf components plus Open Source software combined with in-house applications and/or system software. 5
- 6. • The “no-need-to-know” in terms of the underlying details of infrastructure, applications interface with the infrastructure via the APIs. • The “flexibility and elasticity” allows these systems to scale up and down at will – utilising the resources of all kinds • CPU, storage, server capacity, load balancing, and databases • The “pay as much as used and needed” type of utility computing and the “always on!, anywhere and any place” type of network- based computing. 6
- 7. Services Application Development Platform Storage Hosting Description Services – Complete business services such as PayPal, OpenID, OAuth, Google Maps, Alexa Services Application Focused Infrastructure Focused Application – Cloud based software that eliminates the need for local installation such as Google Apps, Microsoft Online Storage – Data storage or cloud based NAS such as CTERA, iDisk, CloudNAS Development – Software development platforms used to build custom cloud based applications (PAAS & SAAS) such as SalesForce Platform – Cloud based platforms, typically provided using virtualization, such as Amazon ECC, Sun Grid Hosting – Physical data centers such as those run by IBM, HP, NaviSite, etc.
- 8. • SaaS is a model of software deployment where an application is hosted as a service provided to customers across the Internet. • Saas alleviates the burden of software maintenance/support – but users relinquish control over software versions and requirements. • Terms that are used in this sphere include – Platform as a Service (PaaS) and – Infrastructure as a Service (IaaS) 8
- 9. Level 2: Configurable per customer Level 3: configurable & Multi-Tenant-Efficient Level 1: Ad-Hoc/Custom – One Instance per customer Level 4: Scalable, Configurable & Multi-Tenant-Efficient 9
- 10. • Cloud computing enables companies and applications, which are system infrastructure dependent, to be infrastructure-less. • By using the Cloud infrastructure on “pay as used and on demand”, all of us can save in capital and operational investment! • Clients can: – Put their data on the platform instead of on their own desktop PCs and/or on their own servers. – They can put their applications on the cloud and use the servers within the cloud to do processing and data manipulations etc. 10
- 11. • Why is it becoming a Big Deal: – Using high-scale/low-cost providers, – Any time/place access via web browser, – Rapid scalability; incremental cost and load sharing, – Can forget need to focus on local IT. • Concerns: – Performance, reliability, and SLAs, – Control of data, and service parameters, – Application features and choices, – Interaction between Cloud providers, – No standard API – mix of SOAP and REST! – Privacy, security, compliance, trust… 11
- 12. • In parallel there has been backlash against cloud computing: – Use of cloud computing means dependence on others and that could possibly limit flexibility and innovation: • The others are likely become the bigger Internet companies like Google and IBM, who may monopolise the market. • Some argue that this use of supercomputers is a return to the time of mainframe computing that the PC was a reaction against. – Security could prove to be a big issue: • It is still unclear how safe out-sourced data is and when using these services ownership of data is not always clear. – There are also issues relating to policy and access: • If your data is stored abroad whose policy do you adhere to? • What happens if the remote server goes down? • How will you then access files? • There have been cases of users being locked out of accounts and losing access to data. 12
- 13. • Lower computer costs: – You do not need a high-powered and high-priced computer to run cloud computing's web-based applications. – Since applications run in the cloud, not on the desktop PC, your desktop PC does not need the processing power or hard disk space demanded by traditional desktop software. – When you are using web-based applications, your PC can be less expensive, with a smaller hard disk, less memory, more efficient processor... – In fact, your PC in this scenario does not even need a CD or DVD drive, as no software programs have to be loaded and no document files need to be saved. 13
- 14. • Improved performance: – With few large programs hogging your computer's memory, you will see better performance from your PC. – Computers in a cloud computing system boot and run faster because they have fewer programs and processes loaded into memory. • Universal document access: – That is not a problem with cloud computing, because you do not take your documents with you. – Instead, they stay in the cloud, and you can access them whenever you have a computer and an Internet connection – Documents are instantly available from wherever you are 14
- 15. • Instant software updates: – Another advantage to cloud computing is that you are no longer faced with choosing between obsolete software and high upgrade costs. – When the application is web-based, updates happen automatically • available the next time you log into the cloud. – When you access a web-based application, you get the latest version • without needing to pay for or download an upgrade. • Improved document format compatibility. – You do not have to worry about the documents you create on your machine being compatible with other users' applications or OSes – There are potentially no format incompatibilities when everyone is sharing documents and applications in the cloud. 15
- 16. • Unlimited storage capacity: – Cloud computing offers virtually limitless storage. – Your computer's current 1 Tbyte hard drive is small compared to the hundreds of Pbytes available in the cloud. • Increased data reliability: – Unlike desktop computing, in which if a hard disk crashes and destroy all your valuable data, a computer crashing in the cloud should not affect the storage of your data. • if your personal computer crashes, all your data is still out there in the cloud, still accessible – In a world where few individual desktop PC users back up their data on a regular basis, cloud computing is a data-safe computing platform! 16
- 17. • Requires a constant Internet connection: – Cloud computing is impossible if you cannot connect to the Internet. – Since you use the Internet to connect to both your applications and documents, if you do not have an Internet connection you cannot access anything, even your own documents. – A dead Internet connection means no work and in areas where Internet connections are few or inherently unreliable, this could be a deal-breaker 17
- 18. • Does not work well with low-speed connections: – Similarly, a low-speed Internet connection, such as that found with dial-up services, makes cloud computing painful at best and often impossible. – Web-based applications require a lot of bandwidth to download, as do large documents. • Features might be limited: – This situation is bound to change, but today many web-based applications simply are not as full-featured as their desktop-based applications. • For example, you can do a lot more with Microsoft PowerPoint than with Google Presentation's web-based offering 18
- 19. • Stored data might not be secure: – With cloud computing, all your data is stored on the cloud. • The questions is How secure is the cloud? – Can unauthorised users gain access to your confidential data? • Stored data can be lost: – Theoretically, data stored in the cloud is safe, replicated across multiple machines. – But on the off chance that your data goes missing, you have no physical or local backup. • Put simply, relying on the cloud puts you at risk if the cloud lets you down. 19
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