<![CDATA[This is FASCINATING.]]>This is FASCINATING. Researchers were able to pin down the cause of measurable global 60 second power spikes to software that does regular checks on the minute mark. They found large scale battery installations as one major cause, but obviously this is true for any other computerized system that does cron jobs and has a synchronized clock. As weird as it sounds, adding random 0-59.999s delays to cron jobs in Linux distributions and other software would actually help the power grid.

https://www.fz-juelich.de/en/news/archive/press-release/2026/mystery-of-60-second-fluctuations-in-power-grids-solved

]]>https://forum.fedi.dk/topic/6ca10df4-b1bf-4af8-b14b-fc7a5aec506e/this-is-fascinating.RSS for NodeTue, 03 Nov 2026 12:37:56 GMTSat, 31 Oct 2026 10:53:50 GMT60<![CDATA[Reply to This is FASCINATING. on Mon, 02 Nov 2026 07:58:32 GMT]]>@SchwarzeLocke good for you. I readily admit that I didn't expect this effect to be visible on a global scale on the grid.

]]>https://forum.fedi.dk/post/https://infosec.exchange/users/hzulla/statuses/117545783277392389https://forum.fedi.dk/post/https://infosec.exchange/users/hzulla/statuses/117545783277392389Mon, 02 Nov 2026 07:58:32 GMT<![CDATA[Reply to This is FASCINATING. on Mon, 02 Nov 2026 01:06:36 GMT]]>@drwho @benjamineskola @jak2k

sounds about right 😩

]]>https://forum.fedi.dk/post/https://infosec.exchange/users/itgrrl/statuses/117544163487611226https://forum.fedi.dk/post/https://infosec.exchange/users/itgrrl/statuses/117544163487611226Mon, 02 Nov 2026 01:06:36 GMT<![CDATA[Reply to This is FASCINATING. on Mon, 02 Nov 2026 01:05:55 GMT]]>@drwho @hzulla 🀜πŸ’₯πŸ€›β€¬

]]>https://forum.fedi.dk/post/https://infosec.exchange/users/itgrrl/statuses/117544160791484247https://forum.fedi.dk/post/https://infosec.exchange/users/itgrrl/statuses/117544160791484247Mon, 02 Nov 2026 01:05:55 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 21:19:59 GMT]]>@brnrd @hzulla

according to the records, cron originally had only three command line options, -n, -M, and -x.

https://github.com/vixie/cron/blob/9cc8ab1087bb9ab861dd5595c41200683c9f6712/cron.c#L435-L457

]]>https://forum.fedi.dk/post/https://fosstodon.org/users/mibh/statuses/117543272416439790https://forum.fedi.dk/post/https://fosstodon.org/users/mibh/statuses/117543272416439790Sun, 01 Nov 2026 21:19:59 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 19:18:04 GMT]]>@knowprose @hzulla Sure. (I used to run a bunch of servers. I offset many job start times, for convenience.)

]]>https://forum.fedi.dk/post/https://mas.to/users/outer/statuses/117542793044056158https://forum.fedi.dk/post/https://mas.to/users/outer/statuses/117542793044056158Sun, 01 Nov 2026 19:18:04 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:26:33 GMT]]>@casandro @mattblaze @hzulla I don't think it'd be significant compared to what *could* be unleashed by a cron job starting but I agree, there would be something measurable and consistent. If you really wanted to, the wrapper could be a binary and load from RAM disk, I guess you still have the log to consider, there's no getting away from it. Then even checking the time has a small electrical cost, I suppose you can't remove granularity completely.

]]>https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542590460859234https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542590460859234Sun, 01 Nov 2026 18:26:33 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:25:45 GMT]]>@synx508 @mattblaze @hzulla Well most cron don't guarantee precision anyhow, they were not designed for that. It's some daemon running in the background, not a real-time process.

]]>https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542587299996317https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542587299996317Sun, 01 Nov 2026 18:25:45 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:25:32 GMT]]>@outer @hzulla the post is about a grid, not the apple devices people chose to buy. πŸ™ƒ

]]>https://forum.fedi.dk/post/https://mastodon.social/users/knowprose/statuses/117542586465662345https://forum.fedi.dk/post/https://mastodon.social/users/knowprose/statuses/117542586465662345Sun, 01 Nov 2026 18:25:32 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:22:22 GMT]]>@casandro @mattblaze @hzulla wrapping scripts or modifying scripts isn't what I'd call complex and is "self-declaring" and doesn't change the underlying behaviour of cron, which is something you mostly don't want because a lot of things it does *must* be done at exact times.
If you modified the syntax of crontab so particular lines had the time dither switch that would be potentially complex, if you change defaults so you had to specify "exact" that would be even worse. It's likely not complex in implementation within cron, it's complex in implementation in the real world where this stuff is old and established and making changes like that could be misconstrued etc.

]]>https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542574008412385https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542574008412385Sun, 01 Nov 2026 18:22:22 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:13:49 GMT]]>@synx508 @mattblaze @hzulla Yes, but that would still create the first spike, loading and executing that script.

]]>https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542540404798021https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542540404798021Sun, 01 Nov 2026 18:13:49 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:12:56 GMT]]>@casandro @mattblaze @hzulla You can do that by wrapping anything called by cron in a "sleep random number of seconds" script, it's trivial and it's not worth adding complexity to cron for in my opinion. Tools should be simple and easily understood.

]]>https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542536912314569https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542536912314569Sun, 01 Nov 2026 18:12:56 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:11:36 GMT]]>@oclsc @SteveBellovin @mattblaze @hzulla

ACK all around.

Reduce the size of the thundering herd to multiple discrete roaming packs of wild servers.

]]>https://forum.fedi.dk/post/https://oldbytes.space/users/drscriptt/statuses/117542531662096741https://forum.fedi.dk/post/https://oldbytes.space/users/drscriptt/statuses/117542531662096741Sun, 01 Nov 2026 18:11:36 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 18:10:21 GMT]]>@synx508 @mattblaze @hzulla Well unfortunately cron only allows one to set the minute, not the second. AFAIK it was always understood that this time was not supposed to be precise. Just adding some randomness probably isn't to hard to do.

]]>https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542526751037723https://forum.fedi.dk/post/https://f-ckendehoelle.de/users/casandro/statuses/117542526751037723Sun, 01 Nov 2026 18:10:21 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:53:58 GMT]]>@mattblaze @casandro @hzulla I was aware at the time, this was 20 years ago, I wondered about the effect on the data centre's power distribution back then as we did have metered power as well as data transfer. It wasn't my primary motivation, though. The British anecdote about TV viewers putting the kettle on during half-time of football matches or after a particular soap on TV was quite well known so that scaling effect was, too, but with a different cron engine - television schedules. We didn't have many channels to choose from before the 1980s so the effect was likely more pronounced then.

]]>https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542462351338510https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542462351338510Sun, 01 Nov 2026 17:53:58 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:46:06 GMT]]>@synx508 @casandro @hzulla yes, exactly. The software changes required to have cron behave in a way that’s more friendly to the power grid are relatively trivial here. The issue is (apparently) that no one realized (or cared) that synchronized surges in computation can now have a measurable impact at scale (which is an interesting effect).

]]>https://forum.fedi.dk/post/https://federate.social/users/mattblaze/statuses/117542431401295038https://forum.fedi.dk/post/https://federate.social/users/mattblaze/statuses/117542431401295038Sun, 01 Nov 2026 17:46:06 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:15:09 GMT]]>@mattblaze @casandro @hzulla This isn't really a problem that requires changes in the software but rather changes in the way it's used. There is no escaping the necessity of *some* tasks being scheduled at the exact times provided by the various crons. I used to run a fairly big website on meagre hardware and had to dither a lot of scripts to spread CPU load out, this included cron jobs. This also smoothes the power draw.

]]>https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542309661181640https://forum.fedi.dk/post/https://bsd.network/users/synx508/statuses/117542309661181640Sun, 01 Nov 2026 17:15:09 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:10:50 GMT]]>@DamonHD @notsoloud @maya_b it's also a major plot point in the wonderful animated movie "Flushed Away".

]]>https://forum.fedi.dk/post/https://infosec.exchange/users/hzulla/statuses/117542292704682842https://forum.fedi.dk/post/https://infosec.exchange/users/hzulla/statuses/117542292704682842Sun, 01 Nov 2026 17:10:50 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:02:30 GMT]]>@DamonHD

and also more channels to choose from - not everyone watching the same 3 or 4 things anymore

@notsoloud @hzulla

]]>https://forum.fedi.dk/post/https://hachyderm.io/users/maya_b/statuses/117542259945586584https://forum.fedi.dk/post/https://hachyderm.io/users/maya_b/statuses/117542259945586584Sun, 01 Nov 2026 17:02:30 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 17:01:35 GMT]]>@notsoloud @maya_b @hzulla This is called "TV pickup" in the UK. It is diminishing a bit as there are fewer intense shared moments now...

]]>https://forum.fedi.dk/post/https://mastodon.social/users/DamonHD/statuses/117542256348257374https://forum.fedi.dk/post/https://mastodon.social/users/DamonHD/statuses/117542256348257374Sun, 01 Nov 2026 17:01:35 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 16:45:45 GMT]]>@hzulla @knowprose Apple should do something. We wouldn't even know. They play games and lie about our batteries...

]]>https://forum.fedi.dk/post/https://mas.to/users/outer/statuses/117542194100375537https://forum.fedi.dk/post/https://mas.to/users/outer/statuses/117542194100375537Sun, 01 Nov 2026 16:45:45 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 16:16:39 GMT]]>@hzulla as someone who helps operate cloud infrastructure I can truly believe it. Please for th love of god please learn how to jitter

]]>https://forum.fedi.dk/post/https://mastodon.social/users/PsySal/statuses/117542079650251619https://forum.fedi.dk/post/https://mastodon.social/users/PsySal/statuses/117542079650251619Sun, 01 Nov 2026 16:16:39 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 15:56:13 GMT]]>@hzulla In fairness, devs sticking to the minute mark isn't really something you want to fix (because you can't). Instead you have to recognize what causes it and give devs the tools to avoid it by default. Because there's currently not a good way to express "once a minute, regardless of where in the period" on many platforms

]]>https://forum.fedi.dk/post/https://fosstodon.org/users/sehe/statuses/117541999292260218https://forum.fedi.dk/post/https://fosstodon.org/users/sehe/statuses/117541999292260218Sun, 01 Nov 2026 15:56:13 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 15:47:23 GMT]]>@hzulla Wow i've been doing this intuitively for ages without even realizing this. Never schedule exactly on the hour/minute alway stagger/randomize.

]]>https://forum.fedi.dk/post/https://hsnl.social/users/mickert/statuses/117541964601869271https://forum.fedi.dk/post/https://hsnl.social/users/mickert/statuses/117541964601869271Sun, 01 Nov 2026 15:47:23 GMT<![CDATA[Reply to This is FASCINATING. on Sun, 01 Nov 2026 15:22:39 GMT]]>@hzulla This is actually something that I think about!

Maybe not for thr grid exactly, but for anything with more than a couple of instances I want to be nice to services. A ticket at work someone got is because a client isn't staggering something so it absolutely hammers our product.

]]>https://forum.fedi.dk/post/https://hachyderm.io/users/gudenau/statuses/117541867307207047https://forum.fedi.dk/post/https://hachyderm.io/users/gudenau/statuses/117541867307207047Sun, 01 Nov 2026 15:22:39 GMT