1 / 25

COMP1321 Digital Infrastructure

Explore the historical progression of client-server computing, from early dumb terminals to virtualisation platforms, revolutionizing how users access data and services. Understand the significance of servers, thin clients, mixed networks, and virtual machines in modern IT infrastructures.

aroderick
Télécharger la présentation

COMP1321 Digital Infrastructure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COMP1321Digital Infrastructure Richard Henson March2018

  2. Week 19 – Servers, Thin Clients, Connectivity, Mixed Networks, and Virtualisation • Objectives • Explain levels of distribution in client-server networking, and relate the use of different levels to organisational requirements • Explain the process of terminal emulation and how terminal services and other software can deliver this to the desktop • Explain virtualisation and install a virtual machine

  3. A matter of Fashion or Functionality? • Very early days of networking… • no clients… (or even users!) • specialist staff only • all computer input via cards and tape • output only to printers • Original clients (e.g. “Wang VDU) early 1970s really were “dumb”! • microprocessor only just been invented! • interrupt driven processing hadn’t been implemented

  4. Servers provide Services Central host/server • In the early days of organisational computing, the server (host) was king • user device VDU (Visual Display Unit) or Terminal had no processing ability • everything controlled from the centre, with “dumb” terminal on employee’s desk VDUs (screen and keyboard)

  5. The dawn of the “intelligent client” • First “8 bit” processor (Intel 8008) available in 1973… • two years to develop a motherboard & operating system • expected that “users” would write their own apps • 1975, the first microcomputer: The Altair • scope for “intelligence on the desktop” • Many other Micros followed: • Commodore • Atari • Sinclair ZX81

  6. Success of the Business Micro • By 1981, microcomputers popular in the home… • IBM PC (16 bit) was introduced to see whether business would make use of desktop computing… • Business loved the IBM micro • applications became commercially available • large organisations wanted to exchange data… • between desktops • between desktop and server

  7. Desktop Machines Networked • Through OSI & IEEE802 standards, the networked PCs & LANs became possible… • Novell Netware made a PC a server • Communicated with PC clients… very popular • PCs linked to “host” computers previously using only dumb terminals… • DEC PCSA a popular step forward using TCP/IP • meant mainframes running TCP/IP could interface with microcomputers!!!

  8. Ubiquitous Client platforms • Environment for running software even more miniaturised… e.g. • Intel motherboard etc./Windows 10 • Diff Intel motherboard/AppleOS • Smartphone/Android • Sometimes useful to be able to run more than one platform on a single machine…

  9. Clients make services accessible to users… • Servers hold secure data… • should be kept well away from users! • Users can only access data/resources on a client-server network via a request to a server • Depending on the server architecture: • make requests directly via commands inputted from a dumb terminal • make requests from an intelligent client through interprocess communication

  10. Front End and Back End • As client-server computing entered most organisations… • Client desktop – previously VDU - known as “front-end” (or “front office”) • Anything to do with servers/shared applications and information stores – previously the mainframe - known as “back end” (or “back office”)

  11. Clients, Platforms, and Flexibility • Demand for multiple client platforms for the user… • but multiple devices/machines expensive • virtual machine got round this

  12. Virtual Machines • Mounting a platform that is solely software based • running on top of an existing hardware/software platform • e.g. • Intel/Windows 7/8/10 client • Apple client

  13. Virtualisation Platforms • Software environment running on top of an existing platform • allows more than one virtual machine to run on top of a traditional hardware/software platform • Client operating system installed on top of virtualisation platform

  14. Examples: • VMWare • Virtual Box • Citrix • Hyper-V Virtual machine e.g. running Windows 10 Virtual machine e.g. running Server 2016 virtualisation platform Hardware/software platform e.g. Intel/Windows

  15. Virtualisation (Windows 2016 Server, on VMware, etc.) • The use of software to allow a piece of hardware to run multiple operating system images at the same time • possible to run Windows OS under Mac OS • run multiple versions of Windows OS on the same PC • Enables the creation of a “virtual” (rather than actual) version of any software environment on the desktop, e.g. operating Systems, a server, a storage device, an application

  16. “The Cloud” • Outsourcing on a grand scale… • With connectivity via world wide web • “Back to the Future” • Quote from IBM in 1950s: • “I think there is a world market for about five computers.” attributed to J. Watson • “The cloud” will behave like just one massive mainframe computer providing all user services • No powerful clients needed… just enough processing at the client end to run a browser • could be a very small device (Smartphone) • could use wireless protocols to connect…

  17. Web Services and The Cloud • Companies like Amazon, Google (apps), and salesforce.com have created web services (http/s) and made them available to a wider public for storing their data • this approach benefits companies most that are experience relatively quick growth • instead of getting new storage resources every year, organisations can quickly and easily purchase more "cloud space"

  18. Cloud Computing Model

  19. Cloud Services, the Future, and Security • Cloud computing can offer applications as-a-service as well… • a future is predicted where everything is outsourced and no kind of local CPU is even needed • employees will simply have a monitor, keyboard, and mouse that will allow them to connect to the cloud for all of their resources (!) • but will this be secure? And what comeback will organisations have if something goes wrong?

  20. What (physically) is The Cloud? • Lots of servers connected together in clusters to provide different services via the www • uses essentially the same TCP/IP protocols • different ports for different applications • attractive and powerful, but… • disadvantages of outsourcing in terms of control • and with the extra challenge that the user doesn’t know where their data physically is at a particular time… SCARY?

  21. Data Protection, Organisations, and the Cloud • Lot of pressure on organisations to put digital infrastructure “in the cloud” • Less hassle? • someone else managing your data • cheaper… don’t need servers or expensive staff to manage them • don’t even need “back office” premises!

  22. Data Protection and the Cloud • Disadvantages… • concern about loss of control of organisational data • dependent on bandwidth of cloud provider • what if cloud provider gets hacked? • where is the data being held? “third country”? • legal concern whilst UK in the EEA… • UK soon to leave EU? And the EEA? • will then be a “third” country anyway…

  23. Setting up a Virtualisation Platform • Many products available: • Citrix metaframe • VirtualBox • VMWare • Microsoft Hyper V • All available on Windows client converting it to a virtualisation platform

  24. Hyper-V • New for Windows 2008 Server • Subsequently available to Windows clients • PC/Laptop running Windows 10 good platform for virtualisation platforms • e.g. Hyper-V • can run several virtual machines • can even use virtual “switches” to communicate with one another…

  25. Thanks for listening

More Related