arclog archives the log files monthly. It strips off log entries that
belongs to previous months, and then compresses and saves them to archived
files named logfile.yyyymm.gz.

Currently, arclog supports Apache access log, Syslog, NTP, Apache 1 SSL
engine log and my own bracketed, modified ISO date/time log file formats,
and gzip and bzip2 compression methods. Several software projects log (or
can log) in a format compatible with the Apache access log, like CUPS,
ProFTPD, Pure-FTPd... etc., and arclog can archive their Apache-like log
files, too.

WWW: http://search.cpan.org/dist/arclog/