1. CIS 451: Servers, CGI and Log Files Dr. Ralph D. Westfall January, 2009

2. Server Functions deliver files to users manage files that users are requesting example: " could not be found." could not be found server side processing run ASP, PHP and CGI scripts write and/or read databases search engines shopping carts customer services e.g., for credit card accounts

3. Server Functions-2 security owner: can write or delete files on server user has: read access to html files execute access to "script" files maybe password-protected access to files tracking activity "log files"

4. Server Options your own server at your location phone DSL, T1, cable connection, etc.DSLT1cable colocation: your server at their location colocation: high speed access to nearby Internet node you are responsible for technical issues hosting: their server at their location host takes care of most technical issues

5. Popular Server Software Windows Server 2008 (humor) Windows Server 2008humor Apache has some technical advantages is free (open source like Linux)open source has largest share of market (52%)share of market is the server on Cal Poly Intranet LAMP: Linux, Apache, MySQL, PHP LAMPLinux

6. CGI Common Gateway Interface (CGI)CGI is a standard for interfacing applications with servers is what people used before ASP CGI applications are triggered by users' inputs from browsers provides capabilities that HTML doesn't database read and write complex calculations/data manipulation security

7. CGI "Scripting" Languages interpreted UNIX shell scripts (like DOS bat files) Perl, Python and PHP Perl other scripting languages compiled C/C++ programs other executables

8. CGI on a Search Engine browser requests URL from server http://www.google.com/search?q=free server runs the requested script script calls program to access database database returns data to a script script writes data into a web page server sends this page to browser

9. Passing Information to CGI essentially same as for HTML form sending data to ASP.NET "get" appends data to URL (URL encoding).pl is common extension for Perl files

10. Using CGI Scripts server must allow you to run scripts poorly written scripts vulnerable to hackers load script in appropriate directory usually /cgi-bin set permissions (Cal Poly) so file is executable set permissions (Cal Poly) chmod 755 (read and execute) in UNIX (right click on file or directory in WS_FTP) chmod 755 may also need to set write permissions for data files (put them in a different directory)

11. ASP vs. CGI Scripts ASP much easier to use (.NET less so) ASP is growing faster ASP is less powerful (.NET better) not all ISPs offer ASP capabilities UNIX servers need additional software to run ASP or ASP.NET market pressures on ISPs to offer ASP (almost always through IIS, not Apache)

12. Server Log Files HTTP offers extensive capabilities for tracking users/site visitors HTTP logging stores information when file requested browser name/version referring URL (where user came from) search engine key words to find your site user's IP address

13. Logging Terminology hits (# of files requested) vs. visitors impressions (CPM) how many visitors possibly adjusted for length of visit ("stickiness" of site) click-throughs CTR (click-through rate) average "click rate" is less than 0.5%less than 0.5%

14. Log File Analysis Reports how long visitor stayed on page and site most popular visit times referring URL which page on your web site visited first page that went to from your web site country (2 characters ending on IP address).ca=Canada,.fr=France,.kr=Korea

15. Free Log File Analysis Services Webstat (free), Webstat cut and paste JavaScript into your site adds a small logo provides extensive statistics current month historical GoStats eXTReMe Tracking most popular free? eXTReMe Tracking

16. Implications of Log Data? page design good pages, bad pages types of customers keywords to emphasize in page content marketing techniques referring pages

17. Exercise 1a search for log file analysis software or services post discussion list report on findings number of free, cost range for not free? free vs. not free reports available? other useful features? web-based or need to install on own server?

18. Exercise 1b sign up for free hit counter/log analysis and install it on one of your web pages post discussion list report ease of use information requested (# of boxes to fill in, # of pages to complete sign-up) how good were the installation instructions any other issues

19. Income from Web Advertising impressions CPM (cost per 1000) CPM typical rates $10 - $30/1000 visitors need to have at least 10,000 visitors/month click-throughs commissions on sales, e.g. AmazonAmazon up to 15% on sales of specified items other "affiliate programs" (link)link web income calculatorcalculator

20. Exercise 2 search for information on affiliate programsaffiliate programs find one that looks either very bad or very good look for: rip-offs, outrageous scams, etc. post discussion list report reason it was bad or good product, payment scheme other issues

21. Exercise 3 find a map that shows locations of major Internet nodes needs to show in relation to an understandable map or find a list of names of cities that have major Internet nodes are these hard to find? why?