An article detailing five lesser-known features of systemd timers, such as single-instance execution, second-resolution timing, monotonic events, manual triggering, and automatic reporting on failing services.
- **systemd Timers**: Modern replacement for cron with more control, flexibility, and higher resolution.
- **One Instance at a Time**: Automatically prevents multiple timer instances from running simultaneously to avoid resource conflicts.
- **Second-Resolution Timing**: Enables one-second resolution (vs. cron's one-minute) by setting `AccuracySec=1` in the timer file.
- **Monotonic Events**: Triggers timers based on system events like boot-up (`OnBootSec`) or clock changes (`OnClockChange`).
- **Manually Trigger Timed Tasks**: Launch timers and services manually for testing (`sudo systemctl start name-of-your.timer` or `name-of-your.service`).
- **Automatically Report on Failing Services**: Use `OnFailure` directive in service files to send notifications upon failure, supporting multiple notification methods (e.g., email, Slack).
- **systemd-analyze Calendar**: Normalizes dates and times for use in `OnCalendar` statements.