The HTTP server logs an entry for every file retrieved via HTTP. This log, written to /etc/log/httpd.log, is stored in the "Common Log Format," which is used by many World-Wide Web servers.
Each entry in /etc/log/httpd.log consists of one line with seven fields. The fields are, in order:
The IP address of the HTTP client requesting the file.
This field is always "-".
This field is always "-".
The time and date the request was is reported in the format "[Day/Mon/Year:HH:MM:SS]", which is logged in universal time (GMT) rather than the local time zone.
A quoted string is recorded for the method (request type) and file involved in the request.
The status code for the request, as defined in RFC 1945, the HTTP protocol specification. (See below.)
The size of the file in bytes.
Possible values for result codes include:
Success: the requested file was transmitted.
Bad request.
Access to file prohibited.
File not found.
HTTP server disabled.
The size of the log file can be restricted by the option httpd.log.max_file_size.
Some Web servers report size statistics differently for result codes other than 200. For example, a file size of 0 is often reported for result code 304 (Not modified).
The log file grows automatically and is never reset. It is the responsibility of the filer adminstrator to rotate files and empty the log files on a regular basis or when the log file grows too large.