Question

I have an application generating a really heavy big log file every days (~800MB a day), thus I need to compress them but since the compression takes time, I want that logrotate compress the file after reloading/sending HUP signal to the application.

/var/log/myapp.log {
    rotate 7
    size 500M
    compress
    weekly
    postrotate
        /bin/kill -HUP `cat /var/run/myapp.pid 2>/dev/null` 2>/dev/null || true
    endscript
}

Is it already the case that the compression takes place after the postrotate (which would be counter-intuitive)?
If not Can anyone tell me if it’s possible to do that without an extra command script (an option or some trick)?

Thanks
Thomas

Answer 1

The postrotate script does run before compression occurs: from the man page for logrotate

The next section of the config files defined how to handle the log file
/var/log/messages. The log will go through five weekly rotations before
being removed. After the log file has been rotated (but before the old
version of the log has been compressed), the command /sbin/killall -HUP
syslogd will be executed.

In any case, you can use the delaycompress option to defer compression to the next rotation.