chapter4.pptx

IT INFRASTRUCTURE: HARDWARE AND SOFTWARE

IT infrastructure

• Computer hardware• Computer software• Data management technology

• Organizes, manages, and processes business data concerned with inventory, customers, and vendors

• Networking and telecommunications technology

• Technology services • E.g. consultants for systems

integration with legacy systems

IT infrastructure: Provides platform for supporting all information systems in the business

Types of Computers

• Computers come in different sizes with varying capabilities for processing information

• Performance of a computer• FLOPS (Floating point operations per second)

• PCs• Laptops• Server• Mainframe• Workstation• Supercomputer etc

Microcomputers: A computer with a microprocessor

and its central processing unit is known as a microcomputer.

They do not occupy space as much as mainframes do. When supplemented with a keyboard and a mouse, microcomputers can be called personal computers.

A monitor, a keyboard and other similar input-output devices, computer memory in the form of RAM and a power supply unit come packaged in a microcomputer.

These computers can fit on desks or tables and prove to be the best choice for single-user tasks.

Desktop Computers: A desktop computer is

intended to be used on a single location.

The spare parts of a desktop computer are readily available at relatively lower costs.

Power consumption is not as critical as that in laptops.

Desktop computers are widely popular for daily use in the workplace and households.

Laptops Similar in operation to desktop computers,

laptop computers are miniaturized and optimized for mobile use.

Laptops run on a single battery or an external adapter that charges the computer batteries.

They are enabled with an inbuilt keyboard, touch pad acting as a mouse and a liquid crystal display.

Their portability and capacity to operate on battery power

have proven to be of great help to mobile users.

Workstations These  are high-end, expensive

computers that are made for more complex procedures and are intended for one user at a time.

Some of the complex procedures consist of science, math and engineering calculations and are useful for computer design and manufacturing.

Enhanced capabilities for performing a special group of task, such as 3D Graphics or game development. 

Server Type of midrange computer Support computer network, sharing files and

resources They are computers designed to provide services to

client machines in a computer network. They have larger storage capacities and powerful

processors. Running on them are programs that serve client

requests and allocate resources like memory and time to client machines.

Usually they are very large in size, as they have large processors and many hard drives.

They are designed to be fail-safe and resistant to crash.

Mainframe Computer Large organizations use mainframes

for highly critical applications such as bulk data processing and ERP.

Most of the mainframe computers have capacities to host multiple operating systems and operate as a number of virtual machines.

They can substitute for several small servers.

• Large-capacity, high-performance computer that can process large amounts of data very rapidly

• E.g. used by airlines for thousands of reservations per second

Supercomputers The highly calculation-intensive tasks can be

effectively performed by means of supercomputers. • Used in engineering, scientific simulations,

military/weapons research, weather forecasting Their ability of parallel processing and their well-

designed memory hierarchy give the supercomputers, large transaction processing powers.Grid ComputingPower of geographically remote computers connected into single network to act as “virtual supercomputer”

Client/server computing

• Form of distributed computing• Multiple computers linked by a communication link

• Splits processing between “clients” and “servers”• Clients: User point of entry

• Normally a desktop and laptop computers• Servers: Store and process shared data and

perform network management activities• Such as managing printers, backup storage , user

security , authentication etc

Client/server computing• Two-tiered client/server architecture

• Uses two types of machines• Multitiered client/server architecture (N-tier)

• Balances load of network over several levels of servers

• E.g. Web servers and application serversWeb server:Manage and locate web pagesApplication ServerHandles all operations of organization back-end business system

Storage devices Alternatively referred to as external

memory , secondary memory, and auxiliary storage, a secondary storage device is a non-volatile device that holds data until it is deleted or overwritten

Secondary storage Secondary storage is one of the most

valuable assets of the computer. It is storage that's separate from the computer itself, where software and data can be stored on a permanent basis.

Secondary storage is necessary because memory, or primary storage, loses its data when a computer is turned off whereas secondary storage does not.

Therefore, it is commonly known as non-volatile storage. The data on it stays there until it is deleted or overwritten by the user.

Magnetic Storage Magnetic media stores data by assigning a

magnetic charge to metal. This metal is then processed by a read head, which converts the charges into ones and zeros

Hard disks are usually found inside computers to store programs and data

 They are constructed from several key components: Platter - Metallic disks where One or both sides of the

platter are magnetized, allowing data to be stored. The platter spins thousands of times a second around the spindle and spins continuously when in operation. There may be several platters, with data stored across them. The disk is divided into tracks and sectors with data represented by magnetizing spots on the disk.

Head - The head reads magnetic data from the platter. For a drive with several platters there may be two heads per platter allowing data to be read from top and bottom of each

Actuator Arm - used to move the read heads in and out of the disk, so that data can be read and written to particular locations and you can access data in a Random fashion.

Power connector - provides electricity to spin the platters, move the read head and run the electronics

IDE connector - allows for data transfer from and to the platters

Jumper block - used to get the disk working in specific ways such as RAID

How a hard disk works?1. The platters spin around

the spindle2. data is requested to be

read from a particular area of a platter

3. the actuator arm moves the read head to that track

4. Once the data sector that is required has spun around and under the read head, data is read

5. Read data is sent from the IDE connector to main memory

RAID RAID (originally redundant array of

inexpensive disks, now commonly redundant array of independent disks) is a data storage virtualization technology that combines multiple physical disk drive components into a single logical unit for the purposes of data redundancy, performance improvement, or both.

Improvement of Reliability via Redundancy Mirroring

Improvement in Performance via Parallelism Stripping

Magnetic tape Increasingly obsolete, the tape has been a medium

to deliver software and back up data since the early days of computing.

Nowadays they are used mostly for corporate backing up and archiving of data.

Tapes are sequential data stores There is no random access like with a hard disk! Tapes can be several terabytes in size and reading

and writing can be very fast as long as you read or write continuous sections of the tape at once.

Optical storage devices Optical storage devices save data as

patterns of dots that can be read using light.

A laser beam is the usual light source. The data on the storage medium is read

by bouncing the laser beam off the surface of the medium. If the beam hits a dot it is reflected back differently to how it would be if there were no dot. This difference can be detected, so the data can be read.

Dots can be created using the laser beam (for media that is writable such as CD-Rs). The beam is used in a high-power mode to actually mark the surface of the medium, making a dot. This process is known as ‘burning’ data onto a disc.

CD-ROM Compact Disc - Read-Only Memory (CD-ROM) discs can

hold around800MB of data. The data cannot be altered (non-volatile), so cannot be

accidently deleted. CD-ROMs are random-access devices. CD-ROMs are used to distribute all sorts of data:

software , music, electronic books DVD-ROM

Digital Versatile Disc or digital video disc - Read-Only Memory (DVD-ROM) discs can hold around 4.7GB of data (a dual-layer DVD can hold twice that).

DVD-ROMs are random-access devices. DVD-ROMs are used in the same way as CD-ROMs but,

since they can hold more data, they are also used to store high-quality video.

CD-R and DVD-R CD-Recordable (CD-R) and DVD-recordable

(DVD-R) discs can have data burnt onto them, but not erased. You can keep adding data until the disc is full, but you cannot remove any data or re-use a full disc.

CD-RW and DVD-RW CD-Re Writable (CD-RW) and DVD-Re

Writable (DVD-RW) discs, unlike CD-Rs and DVD-Rs, can have data burnt onto them and also erased so that the discs can be re-used.

Solid-State Storage Devices The term ‘solid-state’ essentially means ‘no

moving parts’.  Solid-state storage devices are based

on electronic circuits with no moving parts (no reels of tape, no spinning discs, no laser beams, etc.)

Solid-state storage devices store data using a special type of memory called flash memory

USB Flash drive Memory sticks are non-volatile, random-

access storage devices Small, lightweight USB memory sticks, Portable,

available for many Gigabytes.

Storage Area NetworkStorage networking: SANsConnect multiple storage devices on a separate high-speed network dedicated to storage

Input devices An input device for a computer allows

you to enter information. Input devices convert

the user's actions and analog data sound, graphics, pictures) into digital electronic signals that can be processed by a computer. Digital data (such as from barcode readers, modems, scanners, etc.) does not require any conversion and is input direct into a computer.

Keyboard Keyboard is the most common and very

popular input device which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.

Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet.

Mouse

Mouse is most popular pointing device. It is a very famous cursor-control device having a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.

Generally it has two buttons called left and right button and a wheel is present between the buttons. Mouse can be used to control the position of cursor on screen, but it cannot be used to enter text into the computer.

Touch screen A touch screen is an input device normally layered on

the top of an electronic visual display of an information processing system. A user can give input or control the information processing system through simple or multi-touch gestures by touching the screen with a special stylus/pen and-or one or more fingers

Optical Character Recognition OCR, is a technology that enables you to convert

different types of documents, such as scanned paper documents, PDF files or images captured by a digital camera into editable and searchable data.

MICR (magnetic ink character recognition) MICR is a technology used to verify the legitimacy or

originality of paper documents, especially checks. Special ink, which is sensitive to magnetic fields, is used in the printing of certain characters on the original documents.

Pen-based Input Computer that uses pattern-recognition software to enable it

to accept handwriting as a form of input. A stylus, which may contain special electronic circuitry, is used to write on the computer display or on a separate tablet.

Scanner A scanner is a device that captures images from photographic

prints, posters, magazine pages, and similar sources for computer editing and display. Scanners come in hand-held, feed-in, and flatbed types and for scanning black-and-white only, or color.

Audio input devices  are used to capture sound. In some cases, an audio output

device can be used as an input device, in order to capture produced sound. Microphones. MIDI keyboard or other digital musical instrument.

Sensors device which detects or measures a physical property and

records, indicates, or otherwise responds to it.

Output devices An output device is any peripheral that

receives data from a computer, usually for display, projection, or physical reproduction.

Monitors and printers are two of the most common output devices used with a computer.

Monitors Monitors, commonly called as Visual Display Unit

(VDU), are the main output device of a computer. It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels.

Cathode-Ray Tube (CRT) Flat- Panel Display

CRT A vacuum tube used as a display

screen in a computer monitor or TV. The viewing end of the tube is coated with phosphors, which emit light when struck by electrons.

flat-panel display The flat-panel display refers to a

class of video devices that have reduced volume, weight and power requirement in comparison to the CRT. You can hang them on walls or wear them on your wrists. Current uses of flat-panel displays include calculators, video games, monitors, laptop computer, graphics display.

Printer Printer is an output device, which is used to

print information on paper. There are two types of printers:

Impact Printers The impact printers print the characters by striking

them on the ribbon which is then pressed on the paper.

E.g. DOT MATRIX PRINTER Non-Impact Printers

Non-impact printers print the characters without using ribbon. These printers print a complete page at a time so they are also called as Page Printers.

Laser Printers Inkjet Printers

Sound output- speakers

Batch vs. Online processing• Information systems collect and process information in one of two ways• Batch processing:

• Transactions stored for predefined amount of time, then processed as group

• An example of batch processing is the way that credit card companies process billing. The customer does not receive a bill for each separate credit card purchase but one monthly bill for all of that month

• Online processing: • Transactions processed immediately

Contemporary Hardware Trends

• Integration of computing and telecommunications platforms• Cell phones merging with handhelds• Growth of Internet telephony

• Nanotechnology• Creating computer chips and other devices thousands of

times smaller through manipulating individual atoms, molecules

• Edge computing• Multitier, load-balancing scheme for Web-based applications• Significant parts of Web site content, logic, and processing

performed by smaller, less expensive servers located nearby the user

• Increases response time and resilience and lowers technology costs.

• Autonomic computing• Development of systems that can configure

themselves, heal themselves; e.g. self-updating antivirus software

• Virtualization • Process of presenting a set of computing

resources so they can be accessed in ways that are unrestricted by physical configuration or geographic location

• Server virtualization: Running more than one operating system at the same time on single machine.

Multicore processors  multi-core is usually the term used to

describe two or more CPUs working together on the same chip. Also called multicore technology, it is a type of architecture where a single physical processor contains the core logic of two or more processors.

IT Infrastructure: Computer Software Types of software

System software Operating system

The software that manages and controls the computer’s activities

Utility programs Perform common processing tasks

Language Translators Convert programming language into machine

laguage Device Driver

Tells Os how to use and control a particular device

Application software

Operating System Software• The software that manages and

controls the computer’s activities• Resource management• Memory management• I/O management• Multitasking• PROCESS management• CPU scheduling• User authentication etc

PC and Server OS• PC operating systems and

graphical user interfaces

Application Software and Desktop Productivity Tools

• Application programming languages for business

• COBOL• (Common Business Oriented Language) was one of the

earliest high-level programming languages• COBOL is primarily used in business, finance, and

administrative systems for companies and governments.• C, C++

• Creates Operating systems and application software for PC

• Visual Basic: Visual programming language• Visual Basic (VB) is a programming environment

from Microsoft in which a programmer uses a graphical user interface (GUI) to choose and modify preselected sections of code written in the BASIC programming language.

• Fourth-generation languages• Software tools that enable end-users to develop software

applications with minimal or no technical assistance • Tend to be nonprocedural, may use natural languages• Procedural languages

• Sequence of steps• Tells what do and how to do

• Non procedural language• A computer language that does not require writing

traditional programming logic. Also known as a "declarative language," users concentrate on defining the input and output rather than the program steps required in a procedural programming language such as C++ or Java.

• Natural languages• In computing, natural language refers to a

human language such as English, Russian, German, or Japanese as distinct from the typically artificial command or programming language with which one usually talks to a computer

Categories of Fourth-Generation Languages

Software packages and desktop productivity tools

• Word processing software• A word processor is an electronic device or

computer software application, that performs the task of composition, editing, formatting, and sometimes printing of document

• Spreadsheet software• A spreadsheet is an interactive computer

application program for organization, analysis and storage of data in tabular form. Spreadsheets are developed as computerized simulations of paper accounting worksheets. The program operates on data represented as cells of an array, organized in rows and columns.

• Data management software• A database management system (DBMS) is a

computer software application that interacts with the user, other applications, and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases.

• Presentation graphics• A presentation program is a software package

used to display information in the form of a slide show. It has three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images, and a slide-show system to display the content.

• Software suites• A software suite or application suite is a

collection of computer programs —usually application software or programming software— of related functionality, often sharing a more-or-less common user interface and some ability to smoothly exchange data with each other.

• Example Microsoft office• Web browsers

• A web browser (commonly referred to as browser) is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) and may be a web page, image, video or other piece of content.

Software for the Web: Java, AJAX, and HTML

• Java• Operating system-independent, processor-

independent, object-oriented programming language

• AJAX• Allows a client and server to exchange data

behind the scenes to avoid reloading a Web page after each change

• Hypertext markup language (HTML)• Page description language for specifying

how elements are placed on a Web page and for creating links to other pages and objects

Web services Software components that exchange

information with each other using universal Web communication standards and languages

Open standards Exchange information regardless of OS

and programming languages• XML (extensible markup language)

• SOAP (simple object access protocol)• WSDL (web services description language)• UDDI (universal description, discovery, and

integration)• Service oriented architecture (SOA)

XML Used for web pages more powerful and flexible XML and HTML were designed with different

goals: XML was designed to carry data - with focus on what data is. HTML was designed to display data - with focus on how data looks. XML tags are not predefined like HTML tags are

Web services uses some standard web protocols SOAP• SOAP stands for Simple Object Access Protocol.

SOAP is an application communication protocol. SOAP is a format for sending and receiving messages. SOAP is platform independent. SOAP is based on XML.

WDSL The Web Services Description Language (WSDL)is

an XML-based interface definition language that is used for describing the functionality offered by a web service.

UDDI UDDI is an XML-based standard for describing, publishing,

and finding web services. UDDI stands for Universal Description, Discovery, and Integration. UDDI is a specification for a distributed registry of web services.

SOA ( service oriented architecture) Collection of web services A service-oriented architecture (SOA) is an

architectural pattern in computer software design in which application components provide services to other components via a communications protocol, typically over a network. The principles of service-orientation are independent of any vendor, product or technology

Software Trends Open-source software

OSS is computer software with its source code made available with a license in which the copyright holder provides the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner.

Cloud Computing The practice of using a network of remote

servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer

Mashups Mix and match different software

components to create customized applications

ChicagoCrime.org (google maps with crime data)

Widgets an application, or a component of an

interface, that enables a user to perform a function or access a service.

Can be added to desktop and web pages to provide additional functionality

Example: Current weather conditions

Managing Hardware and Software Technology

• Capacity planning• Process of predicting when hardware system

becomes saturated• Ensuring firm has enough computing power for

current and future needs• Factors include:

• Maximum number of users• Impact of current, future software• Performance measures

• Scalability: Ability of system to expand to serve large number of users without breaking down• Number of visitors can increase on some website

• Total Cost of Ownership (TCO) model• Used to analyze direct and indirect costs to

help determine the actual cost of owning a specific technology• Direct costs: Hardware, software purchase

costs• Indirect costs: Ongoing administration

costs, upgrades, maintenance, technical support, training, utility and real estate costs

• Hidden costs: Support staff, downtime, additional network management

• TCO can be reduced through increased centralization, standardization of hardware and software resources

Total Cost of Ownership (TCO) model

Using technology service providers• Using technology service providers

• Outsourcing• Outsourcing is an allocation of specific

business processes to a specialist external service provider. Most of the times an organization cannot handle all aspects of a business process internally.

• Using external provider to:• Run networks• Host, manage Web site(s)• Develop software (offshore software

outsourcing)• Manage IT infrastructures

• Requires Service Level Agreements (SLAs)- a contract

On-demand (OD) computing is an increasingly popular enterprise model in which computing resources are made available to the user as needed.

• Software as a Service (SaaS) - Firms rent software functions from Web-based services, with users paying either on a subscription or per-transaction basis

• Managing software localization for global business• Local language interfaces

• English not typically standard at middle, lower levels• Interfaces are complex: Menu bars, error messages, online forms, search

results, etc.• Differences in local cultures• Differences in business processes

• All of these factors add to TCO of using technology service providers