1. Web Server Design Assignment #2: Conditionals & Persistence
Old Dominion University
Department of Computer Science
CS 495/595 Spring 2006
Michael L. Nelson

2. Grading
To be done by an automated program that will test most (all?) combinations
assignment is listed under the day it is to be demoed in class
each group will give a 3-4 minute status report the week before an assignment is due!
If you have a question:
the class list
mimic the behavior of a well known Apache server (e.g.,

3. Methods to Support
Same as assignment #1

4. Status Codes to Support
Same as assignment #1, plus:
301 Moved Permanently
304 Not Modified
412 Precondition Failed

5. Request Headers Same as assignment #1, but: and add:
optional: Connection: close
and add:
If-Modified-Since
If-Unmodified-Since
If-Match
If-None-Match

6. Response Headers
Same as assignment #1, plus:
ETag

7. MIME Types
Same as assignment #1

8. Further Guidance Only “strong” ETags need to be computed
Use a logical “AND” when combining:
If-Modified-Since
If-Unmodified-Since
If-Match
If-None-Match
be stingy: all conditions must be satisfied to send data
if conditionals would yield both 304 & 412, then send only the 304
Terminate connections after 15 idle seconds