[hiAndrewQuinn]

Systemd is a pretty neat little thing. It's what keeps me running Ubuntu and Debian servers instead of switching to Alpine, at least in those situations where I can't containerize what I want to do.

The thing that got me into it was systemd timers. I really like being able to split up what should run from when should it run. `cron` works best if you desire simplicity above all else, and Slack used `cron` for a very long time before moving to something more custom. But I ultimately don't feel like the learning curve for systemd timers is that bad, and the benefits it can bring (like writing all your echo statements to journalctl instead of some random hard coded logfile in a script) feel very worth it to me.

[charcircuit]

>`cron` works best if you desire simplicity above all else

It may be simple, but it's config file is hard to comprehend compared to a systemd timer. Being able to just use "Friday 17:00" or "hourly" is so much more readable.

[lloeki]

Debugging and tracability is just nuts too. With a timer and a run-once service it's easy to see what happens, happened, and will happen:

systemctl status foo.timer tells you when it has last triggered and when it will triggered next, if it is still enabled.

systemctl status foo.service tells you if it has been triggered from the timer and when, or ran manually with start

I get the conceptual utter simplicity of cron in place of timer + a script in place of service but in practice systemd is much simpler and more consistent to manage.

[pnutjam]

Exactly, and there are still alot of old school "cron" users who don't touch the better "anacron" processes. I hate managing that stuff. Systemd > Anacron > Cron

[arminiusreturns]

Even worse, when I was finding "crons" run from Java apps with cron4j. I hated on SystemD a lot in the early days, and there are still many legit criticisms that don't have good answers, but I have come to appreciate it's power and usefulness very much. Writing your own units seems so much cleaner than the old way, and I say that as a everyday bash script writer/user. (example, systemd-nspawn for containerization)

PS: mcron is what I have been tinkering with and think will probably replace my systemd timers for most purposes.

https://www.gnu.org/software/mcron/manual/mcron.html#Introdu...

[lloeki]

> a lot of old school "cron" users who don't touch the better "anacron" processes

You're touching on something subtle where, like markdown, all cron look the same until they differ.

[hiAndrewQuinn]

I started writing a "oh, I never found it that difficult" comment. Then I thought to test my own belief and tried to type out a cron schedule for "run this every hour", and... Well...

https://crontab.guru/#*_0/1_*_*_*

Oops. Point taken :)

[Karellen]

As well as the already-mentioned `n * * * *` solution, there's also dropping a symlink in /etc/cron.hourly to the program to run. Or a 2-line shell script if you need to add command-line params. (The other line is the shebang.)

[js2]

The cron.hourly directory is a non-standard Linux concept provided by run-parts. The FreeBSD equivalent is periodic, but that's really for system tasks and doesn't have anything more granular than daily.

[Karellen]

Yeah, but the comparison was specifically comparing to systemd timers, so I'm pretty sure the GP wasn't considering non-Linux compatibility anyway.

[js2]

Run this every hour is:

  0 * * * * this

Adjust the leading digit to whichever minute of the hour you wish to run this.

[hashworks]

While I support systemd timers over cron, AFAIK cron has stuff like @hourly.

[caiusdurling]

Some cron implementations do, it's not portable.

[bheadmaster]

Neither are systemd timers. I don't think there's a single system out there implementing the systemd timer interface.

[dale_glass]

What do you mean? There's a single implementation as far as I know, deployed on many distributions and working identically.

[bheadmaster]

> There's a single implementation as far as I know

That's exactly what I mean.

Systemd itself, including timers, is deeply coupled with the Linux API, and cannot be (easily) ported on any other system. Cron, on the other hand, exists on almost every UNIX-like system.

[cuu508]

systemd also has shorthands like "hourly": https://www.man7.org/linux/man-pages/man7/systemd.time.7.htm...

The man page lists: minutely, hourly, daily, monthly, weekly, yearly, quarterly, semiannually (and "annually" further down in examples).

It doesn't have a "hourly" directory where you can drop in scripts though, AFAIK.

[dmd]

And SLURM's scrontab has @fika, @teatime, and - as of yesterday - @elevenses.

[mrweasel]

I also enjoy that you can ask systemd to validate your timer/cron, in case you struggle with the syntax:

    systemd-analyze calendar "Mon,Tue *-*-01..04 12:00:00"

[jamesponddotco]

As a sysadmin, sandboxing and the general ease of use is what really sold systemd to me.

[girvo]

journalctl alone makes it so good IMO