Admin Digest: Setting Up Your Own Web Server - page 4
Why You Need Your Own Web Server
Once you start getting some traffic on your web site you will be asking yourself questions. What files are people getting? Which area of the site is the most popular? What are the total number of megabytes we transferred last month?
To answer questions of this type you need to look at your logfiles. The server generates at least two logfiles: you can tell it to split up the data into more. There is always an 'error' log and an 'access' log, which are located in the /var/log/httpd directory.
The error log records attempts to get files on the server that fail. For instance if a user makes a typing mistake then the misspelled URL will show up in the error log.
The access log is a list of the URLs that were successfully retrieved. Both logs contain dates, number of bytes transferred and some information on where the request was made from. There is a powerful program for doing this under Linux and other UNIX-derived systems. The program is called analog. The simplest way to use analog is to install it as a package and then type:
Look at report.html with a web browser, and then play around with analog. This program can be configured to extract information in every conceivable way from the server's log files.