1 / 31

The Internet Database Environment

The Internet Database Environment. Chapter 10. Objectives. Describe environment for Internet database connectivity Describe Internet-based business environment Use and define Internet-related terminology Explain purpose of client-side and server-side extensions

guy
Download Presentation

The Internet Database Environment

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. The InternetDatabase Environment Chapter 10

  2. Objectives • Describe environment for Internet database connectivity • Describe Internet-based business environment • Use and define Internet-related terminology • Explain purpose of client-side and server-side extensions • Describe web services and their use for e-commerce • Describe issues for Web-site management • Discuss Web security and privacy issues

  3. Business on the Internet • Electronic Business (e-business) • Development of integrated relationship with customers and suppliers via the Internet • Business-to-Consumer (B2C) – retail • Business-to-Business (B2B) – interaction with suppliers and vendors • Electronic Commerce (e-commerce) • Business transactions, including: • Order processing/fulfillment • Customer relations (CRM) • Electronic data interchange (EDI) • Bill payments

  4. Web-Related Terms • World Wide Web (WWW) • The total set of interlinked hypertext documents residing on Web servers worldwide • Browser • Software that displays HTML documents and allows users to access files and software related to HTML documents • Web Server • Software that responds to requests from browsers and transmits HTML documents to browsers • Web pages – HTML documents • Static Web pages – content established at development time • Dynamic Web pages – content dynamically generated, usually by obtaining data from database

  5. Figure 10-1: Database-enabled Intranet-internet Environment

  6. Some Common Protocols • TCP/IP (Internet Protocol) • TCP (Transport Control Protocol) - used to break apart and rebuild information that travels over the Internet • IP (Internet Protocol) - the main delivery system for info over the Internet • HTTP (Hyper Text Transfer Protocol) • Used for Web pages • Communication protocol used to transfer pages from Web server to browser • HTTPS is a more secure version

  7. Commonly Used Protocols • https • Using an https: URL indicates that HTTP is to be used, but with a different default port and an additional encryption/authentication layer between HTTP and TCP. • Invented by Netscape • Provide authentication and encrypted communication • Widely used on the Web for security-sensitive communication, such as payment transactions

  8. Some Common Protocols • FTP (File Transfer Protocol) • Used to download and upload files • SMTP (Simple Mail Transport Protocol) • Used to send text-based information (e-mail) • Telnet • Used to perform commands on a remote computer

  9. Communications Technology • IP Address • An IP (Internet Protocol) address is a unique identifier for a node or host connection on a network. • An IP address is a 32 bit binary number usually represented as 4 decimal values, each in the range 0 to 255 separated by decimal points (periods/dots) Example: 140.179.220.200 • Every IP address consists of two parts: • One part identifying the network (network address) • One part identifying the node

  10. Figure 10-2: Typical URL Communications Technology • DNS -Domain Name Service • Makes it possible to attach easy-to-remember domain names (such as "wikipedia.org") to hard-to-remember IP addresses (such as 207.142.131.206). • Uniform Resource Locator (URL) • Mnemonic Web address corresponding with IP address • Can include folder location and html file name

  11. Markup Language • Combines text and extra information about the text such as the structure or presentation. <b> Hello </b> <u> World </u> HelloWorld • HTML (HyperText Markup Language) is one of best-known markup languages • Used in the publishing industry in the communication of printed work between authors, editors, and printers.

  12. Internet-Related Languages Standards and Web conventions established by World Wide Web Consortium (W3C) • HTML: Hypertext Markup Language • Markup language specifically for Web pages • SGML: Standard Generalized Markup Language • Markup language standard • XML: Extensible Markup Language • Simplified subset of SGML • Markup language allowing customized tags • XHTML • XML-compliant extension of HTML

  13. Internet Related Languages • SGML is used to write the electronic version of the Oxford English Dictionary. • Sophisticated queries can be performed, as well as easy translation into HTML.

  14. Internet-Related Languages • Java • Object-oriented programming language for applets • JavaScript / VBScript • Scripting languages that enable interactivity in HTML documents

  15. JavaScript Code in a Web Page • Use the <script> tag and set the language attribute to “javascript.” • Your browser retrieves and reads the page from top to bottom, displaying the results of the HTML code and executing JavaScript statements as it goes. (javascript.htm) <h1 align=”center”> Scripting </h1> This is text before the script <br> <script language=”javascript”> <!-- // Writing text on a Web Page document.write (“Welcome”) // Displaying an alert dialog box alert(“You are creating your first script”) // --> </ script> This is text after the script<br>

  16. Internet-Related Languages • Style Sheets • Cascading Style Sheets (CSS) • Control appearance of Web elements in an HTML document • XSL and XSLT • XSL style sheet for XML documents • XSLT used to create HTML documents from XML documents

  17. p { font-family: "Garamond", serif; } • h2 { font-size: 110%; color: red; background: white; } CSS <p> This is a segment of html code</p> <h2> Header. This header appears in red </h2> HTML Internet Related Languages • Cascading Style Sheets • Used to define colors, fonts, layout, and other aspects of document presentation. • Enables the separation of document content (written in HTML) from document presentation (written in CSS) • They are called cascading because more than one can be applied to a Web page

  18. Web Servers • Provide HTTP service to many clients at once • Load balancing approaches: • Domain Name Server (DNS) balancing • One DNS = multiple IP addresses • Place copies of the website on multiple physical servers • DNS returns either a different IP address for each DNS request or a collection of IP addresses • Software/hardware balancing • Only one IP address is published for site • Request at one IP address is distributed to multiple servers • Reverse proxy • All connections coming from the Internet addressed to one of the web servers are routed through the proxy server, • Either processes request locally pass the request to web server. • Store frequently used responses. • Intercept client request - use cached response instead of contacting server

  19. Figure 10-3: Web-to-database middleware Server-Side Extensions • Programs that interact directly with Web servers to handle requests • e.g. database-request handling middleware

  20. Web Server Interfaces • Common Gateway Interface (CGI) • Specify transfer of information between Web server and CGI program • Performance not very good • Security risks • Application Program Interface (API) • More efficient than CGI • Shared as dynamic link libraries (DLLs) • Java Servlets • Like applets, but stored at server • Cross-platform compatible • More efficient than CGI

  21. Client-Side Extensions • Add functionality to the browser • Plug-ins • hardware./software modules that extend browser capabilities by adding features (e.g. encryption, animation, wireless access) • ActiveX • Microsoft COM/OLE components that allow data manipulation inside the browser • Cookies • Block of data stored at client by Web server for later use

  22. Web-to-Database Tools • Active Server Pages (ASP) • Microsoft server-side scripting language • Generates dynamic Web pages • Interfaces to databases in MS Windows-based Web servers • Cold-Fusion • Uses special server-side markup language CFML • Modeled after HTML • Interfaces to databases • Embedded SQL • SQL embedded in 3GL programs • Provides flexible interface • Improves performance • Improves database security

  23. Managing Website Data • Web Security Issues • Prevent unauthorized access and malicious destruction • Privacy Issues • Protect users’ privacy rights • Internet Technology Rate-of-Change Issues • Deal with rapid advances in technology

  24. Web Security • Planning for Web Security • Risk assessment: nature, likelihood, impact, and motivation of security risks • Network Level Security • Web server and DB server on separate LAN from other business systems • Minimize sharing of hard disks among network servers • Regular monitoring of network and firewall logs • Install probe-monitor software

  25. Web Security (continued) • Operating System Level Security • Patch all known OS vulnerabilities • Install anti-virus software with boot-time, file download time, and email reception time virus detection • Monitor server logs for unauthorized activity • Disable services not required to reduce risk of unauthorized access

  26. Web Security (continued) • Web Server Security • Restrict number of users on Web server • Restrict access (minimize number of open ports) • http and https only, if possible • Remove unneeded programs • Restrict CGI scripts to one subdirectory • For Unix, only install minimum software for Web server

  27. Web Security (continued) • Firewall – hardware/software security component that limits external access to company’s data • Proxy server – firewall component that manages Internet traffic to and from a LAN • Router – intermediate device that transmits message packets to correct destination over most efficient pathway • Intrusion Detection System (IDS) – system that identifies attempt to hack or break into a system

  28. Routers to transmit message packets to correct destination Firewall to limit external access to data IDS to monitor and recognize security breach attempts Figure 10-11: Establishing Internet Security

  29. Firewall • A program or hardware device that filters the information coming through the Internet connection into your private network. • Incoming packets of information flagged by the filters are not allowed through. • A company can place a firewall at every connection to the Internet • At every T1 line coming into the company) • Can implement security rules and encryption

  30. Firewalls • Methods to control traffic flowing in and out of the network: • Packet filtering • Packets (small chunks of data) are analyzed against a set of filters. • Proxy service • Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa. • Stateful inspection • Anewer method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information.

  31. Routers • Routers are specialized computers that send your messages and those of every other Internet user to their destinations along thousands of pathways. • Let messages flow between networks, rather than within networks. • A router essentially has two separate but related jobs: • Ensure that information doesn't go where it's not needed -- crucial for keeping large volumes of data from clogging the bandwidth. • Ensure that information does make it to the intended destination.

More Related