Chapter 6: The Cloud

Why Is  the Cloud the Future for Most Organizations?

• The Cloud
• Elastic leasing of pooled computer resources via Internet
• Elastic
• Automatically adjusts for unpredictable demand
• Limits financial risks
• Pooled
• Same physical hardware
• Economies of scale
• Average cost decreases as size of operation increases
• Major cloud vendors operate enormous data centers (web farms).

Why Now?

1. Cheap processors, essentially free data communication and storage.
2. Virtualization technology
3. Internet-based standards enable flexible, standardized processing capabilities.

Cloud does not make sense when:

• When law or standard industry practice require physical control or possession of the data.
• Financial institutions legally required to maintain physical control over its data.

What Network Technology Supports the Cloud?

Most computers today support 10/100/100 Ethernet

Abbreviations used for communications and computer memory speeds

• Communications equipment,
• Kilo = 1000
• Mega = 1,000,000
• Giga = 1,000,000,000
• 100 Mbps = 100,000,000 bits per second.
• Communication speeds expressed in bits, memory sizes in bytes.

Important ISP functions:

1. Provide legitimate Internet address
2. Provide gateway to Internet
3. Pay access fees and other charges to telecoms.

• WAN wireless average performance 1 Mbps, with peaks of up to 3.0 Mbps.
• Typical wireless LAN 50 Mbps.

How Does the Cloud Work?

Carriers and Net Neutrality

• Messages, broken into packets.
• Packets move across Internet, passing through networks owned by telecom carriers.
• Peering agreements - Carriers freely exchange traffic amongst themselves without paying access fees.
• Net neutrality principle
• All data treated equally
• Problem: some people use more bandwidth than others

Internet Addressing

• Public IP addresses
• Identifies a unique device on Internet
• Assigned by ICANN (Internet Corporation for Assigned Names and Numbers).
• Private IP addresses
• Identifies a device on a private network, usually a LAN.
• Assignment LAN controlled.

IP Addressing: Major Benefits

• Public IP addresses conserved
• One public IP address per LAN
• Using private IP addresses
• Eliminates registering public IP address with ICANN-approved agencies.
• Protects against direct attack.

Public IP Addresses and Domain Names

• IPv4
• 165.193.123.253
• Domain name
• Unique name affiliated with a public IP address
• Dynamic affiliation of domain names with IP addresses
• Multiple domain names for same IP address
• URL (Uniform Resource Locator)
• Internet address protocol, such as http:// or ftp://

Domain Registry Company

Go Daddy, or a similar agency, will first determine if desired name is unique worldwide. If so, it will apply to register that name.

Almost all e-commerce applications use a three-tier architecture

1. User tier consists of computers, phones, other devices with browsers that request and process Web pages.
2. Server tier consists of computers running Web servers and application programs.
3. Data tier consists of computers running a DBMS that processes a SQL requests to retrieve and store data.

Commerce server - application program that runs on server-tier computer. Receives requests from users via Web server, takes some action, and returns a response to users. Typical commerce server functions are to obtain product data from a database, manage items in a shopping cart, and coordinate checkout process.

Protocols Supporting Web Services

WSDL, SOAP, XML, and JSON

WSDL (Web Services Description Language) - Standard for describing services, inputs, outputs, other data supported by a Web service. Documents coded machine readable and used by developer tools for creating programs to access the service.

SOAP (no longer an acronym) - Protocol for requesting Web services and for sending responses to Web service requests.

XML (eXtensible Markup Language) - Used for transmitting documents. Contains metadata to validate format and completeness of a document, includes considerable overhead (see Figure 6-15a).

JSON (JavaScript Object Notation) - Markup language used for transmitting documents. Contains little metadata. Preferred for transmitting volumes of data between servers and browsers. While notation in format of JavaScript objects, JSON documents can be processed by any language (see Figure 6-15b).

How Organizations Use the Cloud

How can organizations use Cloud services securely?