A Look at Facebook's Use of Systemd (phoronix.com)

At an event this month (you can find the video of it here), Davide Cavalca, a production engineer at Facebook, spoke about the growing adoption of systemd at the data centers of the company. From a report: Facebook continues making use of systemd's many features inside their data centers. Some of their highlights for systemd use in 2018 includes: Facebook's servers have been relying on systemd for about the past two years. Facebook is using CentOS 7 everywhere from hosts to containers. While relying on CentOS 7, Facebook backports a lot of packages including new systemd releases, Meson, other dependencies, and of course new Linux kernel releases. Facebook is working on "pystemd" as a Python (Cython) wrapper on top of SD-BUS.

Comments

Re:Ugh

[Tailhook]

Amazon Linux — the image used on most AWS EC2 Linux instances — has also changed over to systemd with Amazon Linux 2, released last Jun 26. Amazon Linux was an important sysvinit holdout; if your users expected to use your work on EC2 with Amazon's distro you needed to care about sysvinit. Now that Amazon Linux has moved on there are no important distributions based on sysvinit remaining and it may be safely ignored.

Re:systemd has logged your complaint

[Xenolith0]

But the logging issue is a bigger problem. I miss SysV scripts where even if something didn't get logged, you could at least see it on the console.

Yeah, I know what you mean! Typing "journalctl -u sshd" is impossible to remember! Much easier to just jump on the systemd-hate bandwagon and use strace.

It's SO-FUCKING-ANNOYING that systemd logs all stdout and stderr to the journal! I mean ugh! having to type journalctl. I can't even.

Re:Only one good use-case

[thegarbz]

all of which worked fine here for years

Seriously you realise that systemd was build precisely because the things you listed didn't work fine for years.

shares didn't mount because they tried and failed before there was an IP address

Fix your startup order in the unit file.

things like conky get started in an endless timeout loop

Fix the start conditions in the unit file.

and LP says "just don't do that, EWONTFIX".

He was being polite. He should just tell people to RTFM.

And his clan call us haters.

No. Ignorant maybe, but not haters.

Shades of lost productivity, near windows-like.

Yeah that's what happens when you adopt a system and spend more effort complaining than simply reading the manual.

It was really fun trying to figure out why a system with a failed mount wouldn't shut down clean without a hard power off - because it couldn't unmount what it had failed to mount.

It never ceases to amaze me how people can get their system in that kind of a state.

it caused me a ton of unnecessary unpaid work

Systemd can't help you with a poorly worded employment contract.

Re:Only one good use-case

[DCFusor]

What order, I did an NFS mount in /etc/fstab, which is the documented way that worked for years, and not only did systemd fail to mount it, it failed to respect the bg (backgrounding try again) flag, and then refused to let the system shut down since it couldn't unmount what it had failed to mount - which I verified by mounting manally at the CLI - and then it would unmount it and shutdown normally.
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There was no fine manual to read that I'm aware of when this happened. Just oddball notes all over if you googled about how to fix just this particular bug - which workarounds worked until the next update. You might not have been paying attention.
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Got my system in such a state? What a jerk, you're proving my point. Systemd got it into that state, I did zero, nada, nothing but allow an update to happen.
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I don't have an employment contract - I work for my own outfit, which is a physics lab. It needs a lot of fairly custom machines from little to huge and fast for data aq and control - which is needed as the fusion reactor I'm developing works well enough to make too many neutrons to be safe near....
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If it wasn't a bug that affected a lot of people, why did they complain and get the snotty remark - and then list workarounds findable on google?
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That lovely restart loop on slow starting things is well documented as well, and has a workaround involving setting a longer timeout, which is a nasty hack...
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Pretty sure it's not ignorant to trust "security" updates. I wouldn't have known systemd existed, much less have had time to retrain on hard to find or nonexistent documents that were changing daily...I'm REAL sure that something they broke isn't my fault, and people who tell me otherwise might be the problem.

Re:systemd has logged your complaint

[DCFusor]

Yeah, you're one of the ones who can't even, that's obvious. When this crap just gets added to your system, how are you even supposed to know there's such a thing as journalctl? Some of us, do, you know, real work on this stuff, and only do sysadmin if it's required to set something nifty up. Having to also fix things someone else broke is extra work that isn't needed. The pushback isn't for no reason - systemd really screwed up a lot of people's day. If it just worked...probably would have been another story, despite the terrible architecture.