journald has become the new standard for logging in Linux. When systemd manages units, it uses journald for logging. This article from DigitalOcean provides useful commands for filtering logged information.
Computing Magazine
How To Use Journalctl to View and Manipulate Systemd Logs | DigitalOcean
Posted on the 15 February 2016 by Hean Hong Leong @hongster
How To Use Journalctl to View and Manipulate Systemd Logs | DigitalOcean: