I have been researching log rotation for my server which hosts ~5 fairly high traffic sites. From what I can tell, my options are to use logrotate or to use piped logging with either rotatelogs or chronolog.
logrotate requires a restart of apache and both SIGHUP and SIGUSR1 restarts are less than ideal on high traffic sites, because either you drop a bunch of connections or you need to delay compressing the old log until all child processes have died naturally. Also, downtime can be quite significant if compression is enabled. Would using logrotate - without compression and with graceful restart - and compressing old logs after the fact be the best way to minimize downtime?
chronolog and rotatelogs sound promising, but are not well documented. I couldn't find examples of using either in combination with vhost specific logs. The chronolog website says, "when the expanded filename changes, the current file is closed and a new one opened". Is this globally? Or is that per AccessLog, CustomLog or ErrorLog directive?
Is there a significant difference between chronolog and rotatelogs?