Lighttpd

I patched mod_accesslog to support the automatic rotation of log files based on a strftime-style format string. This patch has been running on my custom build of lighttpd for a number of years now and has always worked well. This method of log rotation avoids the extra processes that would otherwise be required by a cronolog approach.

The patch adds the following boolean configuration item to lighttpd.conf:

• accesslog.auto-rotate

If this value is set to true, then mod_accesslog will treat accesslog.filename as a strftime-style pattern for the purposes of opening (and creating) log files. For example, the following set of configuration options would create one log file for each month, with one directory for each year:

accesslog.auto-rotate = "enable" 
accesslog.filename = "/var/log/lighttpd/%Y/%Y%m.access.log" 

The following directory tree would eventually be created (assuming that lighttpd ran from November 2007 to March 2008):

/var/log/lighttpd/2007/200711.access.log
/var/log/lighttpd/2007/200712.access.log
/var/log/lighttpd/2008/200801.access.log
/var/log/lighttpd/2008/200802.access.log
/var/log/lighttpd/2008/200803.access.log

The patch will not check the filename pattern for a change more often than once a minute. In other words, you can rotate log files on a per-minute basis if you wish, but not on a per-second basis. The check happens each time a log file entry is about to be written, so the check could occur less frequently than once a minute if the server is not very busy.

The most recent version of this patch was based on lighttpd 1.4.15, although it appears to be compatible with 1.4.18 as well.