Rotate log files Whenever a browser downloads information from an Apache Web site, the server stores information about that access in a log file. You use these log files in conjunction with other scripts or software to analyze the traffic on your site. If you've got a busy Web site, that log file can grow quite large rather quickly and become too unwieldy for easy analysis. The answer is log rotation. Rotating your log files means periodically creating a new log file, so that the older one can be archived or sent to an analysis tool without disturbing the current log file. Apache makes it easy with a built-in log file rotation utility called rotatelogs. To use it, edit your httpd.conf file to include the TransferLog directive:

TransferLog "| /usr/local/apache/sbin/rotatelogs /usr/local/apache/var/log/access_log 86400"
 

The example above gives TransferLog the location of the rotatelogs program, as well as the location and name for the log file. The number at the end indicates how many seconds between each log rotation -- in this case 86,400 seconds, or one day.

Apache generates a log file with a base name of access_log followed by a long numeric extension. So you might have one called access_log.0904347600 and then a day later you'd have another one that's got an extension value that's higher by 86,400.