Chapter 6: The Cloud

The cloud

"elastic" leasing of "pooled" computer resources "over the internet"

How can organizations use cloud services securely?

* Virtual Private Network * Using a Private Cloud * Using a Virtual Private Cloud

SOA for three-tier architecture

- Commerce server application formally defines services that browsers can request, the data they must provide with the request and the data that each will receive in response to the request - Java script is used to invoke services - Servers tier can consist of any number of servers at any time and those servers can move around the world - Nothing needs to change in the browser as servers are adjusted - Load balancing program receives requests and sends them to an available server, it also maintains data about the speed and health of the web server it is assigned to allocate work to maximize throughout. - SOA services are defined between web servers and database servers - Cloud is used for multiple other applications across the Internet - Need standard ways of formatting and processing service requests and data

Benefits of CDN

- Decreased, even guaranteed load time - Reduced load on origin server - Increased reliability - Protection from DoS attacks - Reduced delivery costs for mobile users - Pay-as-you-go

Formats of IP Addresses

- IPv4 4 decimal dotted notation 137.190.8.10 only 4 Billion IPv4 addresses for 7 Billion people -IPv6 Longer format 0:0:0:0:0:ffff:89be:80a 340 undecillion addresses On entering the IP address in a browser it connects to the device associated with the IP address on the public internet

When does the cloud not make sense?

- When law or standard industry practice require physical control or possession of the data - Financial institutions might be legally required to maintain physical control over their data Even in this case, benefits of cloud computing can be gained using private clouds and virtual private clouds.

The Internet and internets

- networks of networks -connects LANs, WANs and other internets - Lowercase-i internet is a private network of networks - Uppercase-i internet is the public collection of networks used for transmitting data worldwide

Functions of ISP

- provides legitimate internet address - gateway to the internet - communication channel between the internet and personal computer

choice of cloud service depends on

-Competitive environment -Business Strategy -Technical Resources (Right fit for organization's needs)

Why was the client-server architecture more appealing to organizations than mainframes?

-Less expensive -Servers more scalable as incremental cost was lower -Allowed users access from anywhere in the world as long as they had Internet Connection

Features of the Cloud

-Resource Elasticity -Pooled Resources -Over the Internet

Using Web Services Internally

-build internal info systems using web services -not technically cloud computing = does not have elasticity or pooled resources -advantageously uses cloud standards

Negatives of Cloud

-dependency on vendor -loss of control over data location -little visibility into true security and disaster preparedness capabilities

Why are organizations moving to the cloud?

-lower and known costs -ubiquitous access -improved scalability -elasticity -risk of obsolescence taken by cloud vendor -best of breed security and disaster recovery if large reputable organizations are involved -economies of scale to cloud vendor (selling to entire industry) -outsourcing computing infrastructure helped focus on activities that give a competitive advantage.

The Internet and the US postal system

1. Assemble package (Packets) - Formatted message passes through networks to the web server requesting certain data 2. Domain name (worldwide unique name affiliated with a IP address) - Not necessary for packets to contain domain name 3. Look up address (IP Address) - Number that identifies a particular device Public IP Addresses identify a particular device on the public internet - DNS (Domain name system) is similar to a phone book and assigns domain names to IP addresses - Domain name must be unique worldwide - controlled by a centralized organization named ICANN ( Internet Corporation for assigned names and numbers ) - Org/ Individual can go to a company that applies to an ICANN approved agency to register their domain name. Eg: www.GoDaddy.com - 2016 - US Department of Commerce gave up oversight of ICANN to a diverse group of governments and companies 4. Put address on package (IP Address) - When we enter a domain name into the browser, it sends a request to a DNS server asking for the IP address which it then puts on packets sent to the site - Several Domain names can point to the same IP address ( like family sharing a mailing address) - Affiliation of domain names with IP addresses is dynamic, owner can change IP address associated at its discretion - URL = Uniform resource locator commonly consists of a protocol (http:// or ftp://) followed by domain name or public IP address 5. Put Registered mail stickers on package (TCP) - Transmission Control Protocol (TCP) core Internet Protocol that guarantees delivery by requiring the receiver to send back an acknowledgement that the packet was received. 6. Ship Packages (Packets transported by carriers) - Like packages go through various postal facilities before reaching destination, packets travel through networks - hop is the movement from one network to another - Private IP addresses identify particular device on a private network - All traffic leaving the LAN uses a single shared public IP address (family living in a house share mail address) - All private IP Addresses are managed by a LAN device - Routers (airports) = devices that connect different networks together - Carriers = Owners of routers and networks (Verizon) - Internet Exchange Points = physical locations where internet traffic is exchanged freely - peering agreements = Carriers exchange traffic without charging each other, collect revenue from end users in form of subscription fees) - Some people use more bandwidth than others, carriers argue that they should be able to charge varying rates based on content, application and the user requesting the data

Service-oriented architecture (SOA)

A design philosophy that dictates that all interactions among computing devices are defined as services in a formal, standardized way. SOA makes the cloud possible. Each department would formally state the data it expects to receive with the request and the data it promises to return in response. Every interaction is done in the exact same way, there is no personal contact. Each department is free to change personnel task assignments and to change the way it performs its services, no other department needs to know that a change occurred. work of the department is ENCAPSULATED in the department

JSON (JavaScript Object Notation)

A markup language (such as html) used for transmitting documents. Contains little metadata and is preferred for transmitting volumes of data between servers and browsers. While the notation is the format of JavaScript objects, JSON documents can be processed by any language. preferred for the transmission of voluminous application data

XML (Extensible Markup Language)

A markup language used for transmitting documents. Contains much metadata that can be used to validate the format and completeness of the document, but includes considerable overhead contain as much metadata as application data to ensure that the document is complete and properly formatted used when relatively few messages are transmitted and when ensuring a complete and correct document is crucial WSDLs and SOAP msgs are coded in XML

DoS attack (Denial of Service attack)

A network attack in which an attacker disables systems that provide network services by consuming a network link's available bandwidth, consuming a single system's available resources, or exploiting programming flaws in an application or operating system.

Virtual Private Network (VPN)

A private data network that creates secure connections, or "tunnels," over regular Internet lines Tunnel - virtual private pathway over a public or shared network from the VPN client to the VPN server (IP Address(Encrypts(Msg)Decrypts)IP Address) Original address inside LAN

TCP/IP protocol architecture

A protocol architecture having five layers and one or more protocols defined at each layer. Programs are written by data communications and software vendors to implement the rules of a particular protocol.

FTP (File Transfer Protocol)

A protocol used to move files and folders over a network or the Internet Google drive and Microsoft OneDrive

WSDL (Web Services Description Language)

A standard for describing the services, inputs and outputs, and other data supported by a Web service. Documents coded according to this standard are machine readable and can be used by developer tools for creating programs to access the service.

Three-tier architecture

Architecture used by most e-commerce server applications. The tiers refer to three different classes of computers. The user tier consists of users' computers that have browsers that request and process Web pages. The server tier consists of computers that run Web servers and in the process generate Web pages and other data in response to requests from browsers. Web servers also process application programs. The third tier is the database tier, which runs the DBMS that processes the database.

cloud computing architecture

Computing architecture that allows employees and customers to access organizational data and applications located in the cloud. Applications, data and processing power can be used remotely with a variety of devices without org having to purchase, configure and maintain expensive computing infrastructure

mainframe architecture

Computing architecture that supports connections between a central mainframe and numerous thin clients/computer terminals. -all applications, data, and processing power were located on the mainframe.

Alternatives for connecting to the Internet / Types of WAN connections

Connected to ISP through -DSL -Cable TV line -Wireless phone like connection

Elasticity vs scalability

E- where leased resources can be increased or decreased in a short amount of time S- where resources can be grown over a longer time scale

Internet started taking off

Early 1990s users were connecting their personal computers(stand alone clients) to the internet and organizations were buying servers to host their websites and data (In-house hosting)

layered protocol

Elaborate scheme that provides seamless flow of communication Protocol is a set of rules and data structures for organizing communication

Mainframes

Large-scale high-speed centralized computers used for internal data processing needs. -early 1960s to late 1980s

Traditional on Premises model

Must provide all services internally

How do organizations use the cloud?

Obtain cloud services from cloud service vendors Cloud services are used by different. organizations to different extents -Traditional on Premises -IaaS -PaaS -SaaS -CDNs -Web Service use Internally Depending on the choice of cloud services, org manage less of their infrastructure, platform and software functions

Web servers

Programs that run on a server-tier computer and that manage http traffic by sending and receiving Web pages to and from clients and by processing client requests.

Internet Protocol (IP)

Set of rules and data structures for organizing communication Cloud's web services use the Internet and so the protocols that run the Internet also support Cloud processing

Interorganisational processing

Used to be based on meetings of developers and was long, slow, expensive and prone to failure Now the computer industry has settled on a set of standard ways of requesting and receiving services over the internet which takes only fractions of seconds

Software as a Service (SaaS)

Vendor provides not only hardware infrastructure and an operating system but also applications programs and databases Buying hardware, loading an operating system, setting up a database and installing software all done by vendor

Four Standards

WSDL SOAP XML JSON

Over the internet

When applied to cloud computing, the provisioning of worldwide servers over the Internet. resources are accessed over the internet Reduces cost as physically managing own computing infrastructure is costly.

Connecting LAN to Internet

When we connect to internet we are actually connecting to a WAN through ISP

Private Cloud

a cloud that is owned and operated by an organization for its own benefit can use elastic load balancing complexity of managing multiple database servers security within the org but no secure access from outside the infrastructure - prefer VPN to access the private cloud from outside advantages of elasticity but questionable benefit as they cannot use the idle servers when they don't need them Could be useful to companies with processing loads across subsidiary business units or across different geographical regions

Computer Network

a collection of computers that communicate with one another over transmission lines or wirelessly

Internet Service Provider (ISP)

a company that provides access to the internet for a monthly fee they then pay internet access fees on our behalf

web page

a document coded in, usually, html

Web Farm

a facility that runs multiple web servers

Intranet

a private internet that is used exclusively within an organization

Thin clients/computer terminals

a screen, a keyboard, and a network connection

Virtual Private Cloud (VPC)

a subset of a public cloud that has highly restricted, secure access can store sensitive data on its own infrastructure and less sensitive data on the VPC can gain the benefit of cloud storage and processing fro the part of data which does not need physical control

Content Delivery Network (CDN)

a system of hardware and software that stores user data in many different geographical locations and makes those data available on demand Real time decisions are made to provide fastest content delivery. Request is transmitted to a routing server that determines which CDN server will deliver the data needed fastest.

client/server architecture

allows clients to send requests across the internet to servers. Servers respond by sending back data top clients. Applications and data can be stored on both clients and servers or either Processing power is shared between clients and servers 1990s - 2000s

SMTP (Simple Mail Transfer Protocol)

application layer protocol used for email transmissions

Commerce server

application program that runs on a server-tier computer

Wide Area Network (WAN)

connects computers at different geographic locations

Local Area Network (LAN)

connects computers that reside in a single geographic location on the premises of the company that operates the LAN can be 2 or several hundred

Personal Area Network (PAN)

connects devices located around a single person most PAN devices connect wirelessly to other devices located within 10 m

SOHO (Small office/home office)

fewer than a dozen or so computers and printers

WAN wireless connection

how iPhone, iPad, and Kindle connect to internet -slower than LAN counterpart

Elastic

leased computing resources can be increased or decreased dynamically, programmatically, in a short span of time and that organizations pay for only the resources they use Cloud based hosting offers considerable elasticity at a fraction of cost of purchasing the server capacity.

What are the components of LAN? (half-mile radar)

located on property controlled by the organization that operates the LAN, can run cables to connect -Small office/Home office (SOHO LAN) -Wired connectivity -Wireless connections

SOAP

protocol for requesting web services and for sending responses to web service requests uses http to send and receive SOAP messages

HTTP (Hypertext Transfer Protocol)

protocol used between browsers and web servers Communication possible between browser and server as they both follow rules of http https is the secure version of http

Cable Line

provide high-speed data transmission using cable television lines cable company installs high capacity optical fiber cable to a distribution center in each neighborhood - connects to regular cable lines Cable signals do not interfere with TV signals Performance varies, usually downloads at 50Mbps and uploads at 512 Kbps (typically lower) In most cases the download speeds of cable lines and DSL is same use their own protocol

Digital Subscriber Line (DSL)

provides high-speed digital data transmission over standard telephone lines using broadband modem technology, allowing both Internet and telephone services to work over the same phone lines device at the telephone company separates phone signals from computer signals and sends the latter to the ISP use their own protocol for data transmission

Institute for Electrical and Electronics Engineers (IEEE)

sponsors committees that create and publish protocol and other standards for LAN = IEEE 802 Committee IEEE 802.3 protocol = wired LAN connections/ Ethernet 10/100/1000 (Mbps) Ethernet is the most common switches detect speed of a given device and can handle and communicate with it at that speed. Today speeds of up to 1 Gbps are possible (wired) Communications speed units (bits) =/= computer memory units (bytes) One byte = 8 bits IEEE 802.11 protocol = wireless LAN connections Latest version is 802.11 ac , speeds of up to 1.3 Gbps Bluetooth = common wireless protocol to connect PAN devices transmission of data over short distances, replacing cables

Infrastructure as a Service (IaaS)

the cloud hosting of a bare server computer, data storage, network, and virtualization cost savings of IaaS over traditional on premises hosting can be substantial

Net Neutrality

the principle that all Internet traffic should be treated equally by Internet Service Providers 2015 - Federal Communications Commission (FCC) approved new regulations that ensured ISPs could not discriminate between different types of internet traffic (like a utility) 2017 - reversed ruling - classified Internet services as Information service - ISPs could discriminate

Pooled

the situation in which many different organizations use the same physical hardware through virtualization Virtualization enables rapid creation of new virtual machines. Increases scalability and reduces costs as cost of physical server is spread over multiple virtual servers.

Platform as a Service (PaaS)

vendors provide hosted computers with an operating system, runtime environment, and a middleware like a web server or a DBMS Org add their own applications to the host