CS 330 - Final Exam

CS 330. Winter 2024. Taught by Kevin Lanctot

Topic 1

IT Infrastructure and Emerging Technologies

Why should you care about IT?

• Distinguish gibberish from genuine vocabulary

• Make better decisions if you understand the options and their trade offs

Social Engineering

When hackers use their knowledge of psychology to trick people into divulging confidential information

e.g. leaving a USB in the bathroom with a virus on it

Measuring Data

byte (B) = 8 bits (b)

K>M>G>T

powers of 1024 unless specified

M = K², G = K³, T=K^4

Word Size

Measure of how many bits a processor can transfer or manipulate in parallel

Backwards Comptability

When the new version of a component is designed to work with the remaining older components

E.g. new consoles are designed to work with old discs

Basic components of IT infrastructure (7)

• Processor

• Main Memory

• Secondary Storage

• Input Devices

• Output Devices

• Communication Devices

Processor Varieties

• Efficiency

  • Used in phones

  • No fan needed

  • Minimal transistors

• Speed

  • Used in laptops

  • Need a fan to keep cool

  • Complex; many transistors

Processor

• Executes simple instructions quickly

• Programs written in Python, etc. converted into these simple instructions

Processor Components

• Program Counter

• Instruction Register

• Arithmetic Logic Unit

• Registers

• Control Unit

• Cache

Processor Caches

• Amount of memory on the processor chip

• Speed at which you can access memory depends on the size of the memory

• Smaller is faster

Multicore Processors

Each core acts like a separate processor and may share resources and access to the computer

Processing Power

Reported as clock speed and based on many factors like:

• number of cores

• word size

• bus speed (speed that data can be moved between processor & main memory)

Clock Speed

• ms = s/thousand

• us = s/million

• ns = s/billion

• ps = s/trillion

• MHz = million ticks/s

• GHz = billion ticks/s

Storage Devices

• Standard Random Access Memory (SRAM)

• Dynamic Random Access Memory (DRAM)

• Solid State Drive (SSD)

• Hard Drive (HD)

• USB, SD card

• DVD

Gap between CPU & Memory Performance

Processor performance has been increasing much faster than memory performance

Memory hierarchy

• (fastest, most expensive, smallest capacity)

• Registers

• Caches

• RAM

• SSD

• HD

• Network Storage

• Off-Site

  • (slowest, cheapest, largest capacity)

Static vs Dynamic RAM

Static: expensive but faster, used for registers

Dynamic: cheapest but slower, used for RAM

Main Memory

• Registers, Caches, and RAM

• Directly accesses any randomly chosen address in roughly the same amount of time

• Faster, expensive, volatile

Secondary Storage

• SSD or HD

• Not directly accessible by the processor

• Slower, cheaper, non-volatile

Mean Time Between Failures

More likely to fail young due to manufacturer error or old due to being worn out

Annualized Failure Rate

(1 - x%)^y = % of drives still working after y years

Tracks failures of hard drives and makes the data public

Pros & Cons of SSD

• Pros

  • Faster

  • Lasts Longer

  • No moving parts can wear out

• Cons

  • Expensive

  • Wears out sooner when writing a lot of data

  • Data can fade over time

Hybrid Drives

Combine a smaller SSD (for speed) with a larger HD (for capacity & cost)

Assessing Performance of Secondary Storage

• Price per gigabyte: HD

• Capacity: HD

• Bandwidth (rate of transfer): SSD

• Durability: DVD or SSD

Will adding RAM improve computer performance

It depends

Speciality Computres

• Mainframes

  • reliable, Hot Swap, support many users

• Supercomputers

  • speed, millions of cores

• Microcontrollers

  • simple processors

IT Infrastructure

Share technology resources that provide the platform for the firm’s information system applications

5 Stages of IT Infrastructure

• Mainframe/Mini Computer

  • one centralized system controlled by operators

• Personal Computers

  • used by one person

• Client/Server

  • clients request and use services (cheap)

  • servers run applications and provide them to others (expensive)

  • e.g. Google searches

• Enterprise Computing

  • links together different networks and applications

• Cloud & Mobile Computing

  • extension of client/server but rather than a server it’s a shared pool of resources (e.g. iCloud storage)

Peer-to-Peer

Every machine in the network consumes and provides services at the same time

Drivers of Technology

• Moore’s Law

• Law of Mass Digital Storage

• Metcalfe’s Law

• Declining Communications Costs

• Creation of Technology Standards

Moore’s Law

The number of transistors that can fit on a chip doubles every 18 months, meaning that computing power doubles or the price of computing falls in half every 18 months

As more transistors fit on a chip, the cost of a single transistor on that chip decreases

Law of Mass Digital Storage

• The amount of digital information is increasing exponentially, but the cost of storing it is decreasing exponentially

• HD capacity is increasing

• Amount of data stored per dollar doubles every 15 months

Metcalfe’s Law

The value of a network grows exponentially as a function of the number of network members

Declining Communication Costs

Communication costs have been declining

The lower the cost of communication, the more reliance on it for business operations

Creation of Standards

Allows for competition, increases interoperability and reduces costs

Drivers of Technology

• Computer Hardware Platforms

• OS Platforms

• Enterprise Applications

• Data Management and Storage

• Network and Telecom Platforms

• Internet Platforms

• Service Platforms

Computer Hardware Platforms

• Client Machines (e.g. desktops)

• Server Machines (e.g. rack or blade servers)

• Server Farms: collections stored in large, windowless, AC-controlled rooms

Operating System Platforms

• OS: manages a computer’s hardware and software resources

• e.g. linux, IOS

Enterprise Applications

Integrates business applications and services across many different departments

Data Management and Storage

• DBSM: Organize and store company data

• Storage: HD, SDD, RAID

• Backup: Online (real-time), Offline (EOD)

RAID Architecture

Using many drives to achieve improvements in reliability, availability, performance and capacity

e.g. Disk Striping, Disk Mirroring, Parity

Network Hardware

Network: Group of computers linked together to share resources

• hub: data received is sent to all connected devices

• bridge: only one input and one output

• switch: many ports

• router: switch that connects different networks together

Internet Providers

• Internet Service Provider: Provides the link from your home or company network to the rest of the internet

• Web Development: uses languages like html and JavaScript

• Static Websites: do not change unless a person edits the page

• Dynamic Websites: created using a combination of scripted and database queries

• Web Hosting: needs a server, domaine name, IP address, web server

Service Platform

Collection of services that enable the information system to function

Contemporary Hardware Trends

1. Mobile Digital Platform

2. Consumerization of IT and BYOD

3. Grid computing

4. Virtualization

5. Cloud computing

6. Green computing

7. High-Performance and Power-Saving Processors

8. Autonomic Computing

Mobile Digital Platform

• Internet access happens via highly portable devices

• Integration of voice and data brings together two historically distinct global networks

Consumerization of IT

Technology was meant for the consumer moves into the business world. Companies must consider:

• boundaries

• security

• software availability

• ownership

• privacy

Grid Computing

Simulates a supercomputer by organizing the computational power of a network of computers.

Benefit: capable of working on problems that require short-term access to large computational capacity

Limitation: only tasks that can be parallelized can be take advantage of grid computing

Virtualization

Creation of a virtual rather than the actual version of something

• One looks like something else (Mac look like Windows)

• Many looks like one (RAID Disk Stripping)

• One looks like many (server looks like smaller computers)

Benefits: better resource management, less expensive, less energy

Meeting Peak Demand

• Load Balancing

• Cloud Computing

• On-Demand Computing

Load Balancing

• distribute the work load evenly across many servers

• Pros: gracefully deals with crashes, upgrades, seasonal peak demands, average down time reduced

• Cons: must purchase and maintain HW that are rarely used

Cloud Computing

• leasing from another company that is accessed over the internet

• e.g. infrastructure (OneDrive), platform (matrix libraries), software (Google Docs)

On-Demand Computing

• firms off-load peak demand for computing power to remote, large-scale data processing centers

• Pros: cost, convenience, flexible

• Cons: privacy, liability, legal, loss of control

Green Computing

Design and use of the computer systems in a way that minimizes their impact on the environment

• reduce power consumption

• reduce use of standby power

• reuse: make parts available for repair older devices

• recycle e-waste (sanitize first - deleting old files note enough)

High-Performance and Power-Saving Processors

Multicore processors where cores can disconnect from power when not in use. Common in cell phones

Autonomic Computing

Industry-wide effort to develop systems that are capable of self-management

e.g. P2P systems like Skype

Future Trends

Nanotechnology: using nanostructures to build devices

Quantum Computing: quantum computers use a quantum property of electrons to represent data. Minimizes the number of steps needed to arrive at a result for some problems

Contemporary Software Trends

1. Linux & Open-Source Software

2. HTML

3. Web services and service-oriented architecture

4. Software outsourcing

Open-Source Software

• software that is available to use, modify and distribute by anyone. May be an old product that is no longer supported

• open-source challengers can compete against other company’s products

• Pros: lower initial cost, more security, less bugs, flexibility

• Cons: harder to {use, meet customer demands, be compatible}

HTML

• HTML: Hypertext Markup Language

• the format for displaying information on the internet

Web Services and Service-Oriented Architecture

• Web services: software components that exchange info with each other using web communication standards & languages

• XML: eXtensible Markup Language which is HTML with the added benefit of knowing what the data means

• XML provides format for programs to exchange information

• SOA: use of web services to achieve integration among different applications and platforms

Software Outsourcing

• purchasing customizable generic software packages

• contract custom software development or maintenance

• Software as a service: software available from the cloud

Management Issues

• Dealing with Change

• Management and governance

• Infrastructure Investments

Dealing with Change

• Firms need to be able to grow or shrink

• Scalability: ability to expand to serve a changing number of users without breaking down

Management and Governance

Decentralized (IT for each department) or centralized (IT for whole company), or a mixture of both

Infrastructure Investments: Total Cost of Ownership

• Capital expenditure: fixed, one-time cost

• Operational expenditure: ongoing expenses

• Direct cost: costs paid for directly

• Indirect cost: cost due to lost productivity

• Reducing Costs (more managed, lower indirect cost)

  • Unmanaged: users can install any application and change any setting

  • Locked and well-managed: policies in place to restrict what an employee can do

Infrastructure Investments: Competitive Forces

1. Demand for Services

2. Business Strategy

3. IT Strategy

4. IT Assessment

5. Competitor’s Services

6. Competitor’s IT Investments

Topics 2

Databases

Flat Files

Pros: simple, easy to sort, data all in one place

Cons: limited security, lack of concurrent access, lack of data integrity

Database and DBMS

• Database: collection of related information stored in structured form

• DBMS: programs that manipulate a database

  • Provides integrity, data independence, enable data sharing

Relational Database

• entities: rows

• attributes: single value

• domain: set of values for an attribute

• record: collection of attributes for a row

• table: group of records

• relation: set of records

• relational database: collection of tables

Goal: reduce redundancies

Limitations: multimedia, arrays, unstructured text, hierarchical data

Primary Key

Minimum set of attributes whose values are unique in each row of a table. Used to uniquely identify individual entities

Composite key: two or more attributes that make up a primary key

Candidate key: when multiple primary attributes could be the primary key

Foreign key: primary key of another table

How Data is Stored

• physical scheme/physical view: how it’s stored

• external schema/logical view: how it’s used

Different Views for Different Groups

• Single global view: conceptual schema/global view

• Many individual views: external schema/logical view

Database Management System (DBMS)

Remove details related to storage and access from application programs. Contents can be accessed using a data manipulation language. Contents must be clearly defined using a data definition language

SQL

• Most commonly used language to create, manage and query a database

• Select: finds rows that match a criteria

• Join: adds relevant columns from another table

  • Project: only include certain columns

Hierarchical Database

A tree that captures the relationship among the data: a parent can have many children

Network Database

Hierarchical Database except children can have multiple parents. Faster than relational databases

Object-Oriented Database

• Stores both types of data and procedures that manipulate the data. can be slow

• Inheritance: grad-student includes all attributes of a student plus some additional ones

• Polymorphism: students and grad-students respond to the same operations

Criteria for Good Design

• Correctness

• Completeness

• Minimum Redundancy

Boyce-Codd Normal Form

every attribute for an entity depends only on the candidate keys (and not other attributes)

Functional Dependency

A → B

Knowing the value of A means that there is only one possible value for B

Data Warehouse

Decision support database that is maintained separately from the organization’s operational database. Used for decision support and operational

non-volatile, integrated, time-variant

Data Warehouse vs Data Marts

Data Warehouse:

• collects info that spans the entire organization

• requires extensive business modelling

Data Marts

• departmental subsets focused on select subjects

• faster to roll out

Online Analytical Processing (OLAP)

• Supports multidimensional data analysis

• enables users to view the same data broken down in different ways along different dimensions

• dimensions characterized by measures: numerical costs like revenue

• Hierarchies: different levels of detail

• Granularity: level of detail

Data Mining

Automatically analyzes large pools of data

• Associations: occurrences linked to a single event

• Sequences: events linked over time

• Classifications: discover properties of predefined groups

• Clusters: discover properties but the classifications are unknown

• Forecasts: predict future values

Managing Data Resources

• Information Policy: Rules for sharing, disseminating, acquiring, standardizing, classifying, and inventorying information

• Data Quality Audit: accuracy and completeness

• Data Cleansing: Detecting and Correcting Data

Topic 3

Networking

Computer Network

• two or more computers connected together

• Network Interface Card: allows a computer to be connected to the network

• Network Operating System: routes and manages communications on the network and coordinates network resources

Network Components

• Connection medium

• Dedicated servers

• Hubs, bridges, and switches: connects machines on one network

• Routers: connects 2 or more networks

• Firewall: prevents outsiders from obtaining unauthorized access, tracks recently visited websites

Packet Switching

• Circuit Switching: a path between a pair of wires connecting the source and the destination. Wastes network resources

• Packet Switching: data is broken down into packets, sent from source to destination, and reassembled

Types of Networks

• Topology: how are the nodes connected

• Geographic Scale: how big is it

• Protocol: what are the rules for communication

• Transmission media: wired, fibre, wireless

• Services: e-mail, printing, file transfer

Popular Topologies

Star, Bus, Ring

Popular Geographical Scales

NFC < PAN < LAN < WAN

Internet Protocol Suite

Set of rules governing how data is exchanged in a network

• Application Layer: defines protocols applications to exchange data (HTTP)

• Transport Layer: sets up and manages the connection. Handles flow control, congestion, and reliability

• Internet Layer: addresses and routes a packet

• Network Interface Layer: transports bits

Physical Transmission Media

• Twisted Pair of wires

• Coaxial cable

• Fiber optica cable

• Wireless transmission

Wireless

• Bluetooth, wifi, wimax

• 3G-5G Generation Cell Networks

• Cell towers support multiple technologies

• Internet of Things: extension of the internet devices like smart thermostats

Internet

An internet: collection of networks

The internet: collection of local, regional, national, and international computer networks linked together

A way to link up different networks together

Web

• WWW: just one service available

• The Web: collection of interconnected documents and other resources, linked by hyperlinks

• HTTP: structures the communication between browser and website

• HTML: file type that a browser understands

• Uniform resource locator (URL): every webpage has a unique address