1. 20-753: Fundamentals of Web Programming 1 Lecture 11: Web Server Case Study Fundamentals of Web Programming Lecture 11: Web Server Case Study

2. 20-753: Fundamentals of Web Programming 2 Lecture 11: Web Server Case Study Today’s Topics The Apache Web Server www.apache.org www.apache.org –Structure –Differentiators –Server Directories –Server Configuration –Server Control

3. 20-753: Fundamentals of Web Programming 3 Lecture 11: Web Server Case Study Structure Web server runs as a background (“demon”) process called httpd Listens for connection requests on port 80 (usually) Implements the HTTP protocol For a typical enterprise, runs on a Unix server and is started automatically at system boot time

4. 20-753: Fundamentals of Web Programming 4 Lecture 11: Web Server Case Study Differentiators Security features Flexibility in configuration Cost ($0!) Result: most commonly-used web server today Best bet for a reliable, inexpensive small-to-mid-size web site: a PC running Linux and Apache

5. 20-753: Fundamentals of Web Programming 5 Lecture 11: Web Server Case Study Server Directories The document root –“top level” of the server –subdirectories match URL path –e.g. /home/httpd/html/PowerPoint http://localhost/PowerPoint Scripts directory –usually, /home/httpd/cgi-bin –config. option: scripts anywhere

6. 20-753: Fundamentals of Web Programming 6 Lecture 11: Web Server Case Study Server Directories Log Directory –access_log: all the HTTP requests –error_log: requests which resulted in an error message to the user –Other: specialized logs for extra server modules; e.g., servlet_log

7. 20-753: Fundamentals of Web Programming 7 Lecture 11: Web Server Case Study Server Configuration httpd.conf –File which controls all aspects of server configuration –Found in /etc/httpd/conf/ subdirectory mime.types –Determines what HTTP headers the server returns for different filename extensions; can be customized

8. 20-753: Fundamentals of Web Programming 8 Lecture 11: Web Server Case Study Server Control Starting –apachectl start Stopping –apachectl stop Restarting –apachectl restart –useful when tweaking httpd.conf (tweak/restart, tweak/restart, … )

9. 20-753: Fundamentals of Web Programming 9 Lecture 11: Web Server Case Study Putting It Together Detailed Walkthrough –Server Directories –Server Logs –Server Configuration Files –Server Control Commands