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Ask Slashdot: Can You Say Something Nice About Systemd?
ewhac writes: "I'm probably going to deeply deeply regret this, but every time a story appears here mentioning systemd, a 700-comment thread of back-and-forth bickering breaks out which is about as informative as an old Bud Light commercial, and I don't really learn anything new about the subject. My gut reaction to systemd is (currently) a negative one, and it's very easy to find screeds decrying systemd on the net. However, said screeds haven't been enough to prevent its adoption by several distros, which leads me to suspect that maybe there's something worthwhile there that I haven't discovered yet. So I thought it might be instructive to turn the question around and ask the membership about what makes systemd good. However, before you stab at the "Post" button, there are some rules...
Bias Disclosure: I currently dislike systemd because — without diving very deeply into the documentation, mind — it looks and feels like a poorly-described, gigantic mess I know nothing about that seeks to replace other poorly-described, smaller messes which I know a little bit about. So you will be arguing in that environment."
Nice Things About systemd Rules:
Bias Disclosure: I currently dislike systemd because — without diving very deeply into the documentation, mind — it looks and feels like a poorly-described, gigantic mess I know nothing about that seeks to replace other poorly-described, smaller messes which I know a little bit about. So you will be arguing in that environment."
Nice Things About systemd Rules:
- Post each new Nice Thing as a new post, not as a reply to another post. This will let visitors skim the base level of comments for things that interest them, rather than have to dive through a fractally expanding tree of comments looking for things to support/oppose. It will also make it easier to follow the next rule:
- Avoid duplication; read the entire base-level of comments before adding a new Nice Thing. Someone may already have mentioned your Nice Thing. Add your support/opposition to that Nice Thing there, rather than as a new post.
- Only one concrete Nice Thing about systemd per base-level post. Keep the post focused on a single Nice Thing systemd does. If you know of multiple distinct things, write multiple distinct posts.
- Describe the Nice Thing in some detail. Don't assume, for example, that merely saying "Supports Linux cgroups" will be immediately persuasive.
- Describe how the Nice Thing is better than existing, less controversial solutions. systemd is allegedly better at some things than sysvinit or upstart or inetd. Why? Why is the Nice Thing possible in systemd, and impossible (or extremely difficult) with anything else? (In some cases, the Nice Thing will be a completely new thing that's never existed before; describe why it's good thing.)
We will assume out of the gate that systemd boots your system faster than ${SOMETHING_ELSE}, so no points for bringing that up. Bonus points are awarded for:
- Personal Experience. "I actually did this," counts for way more than, "The docs claim you can do this."
- Working Examples. Corollary to the above — if you did a Nice Thing with systemd, consider also posting the code/script/service file you wrote to accomplish it.
- Links to Supporting Documentation. If you leveraged a Nice Thing, furnish a link to the docs you used that describe the Nice Thing and its usage.
I've done migrational upgrades to System-d with Arch Linux with zero problems in addition to using it with new installations. It works fine, and I'm still really confused about the jihad-level hatred it seems to engender in some people.
AntiFA: An abbreviation for Anti First Amendment.
My problem with things like systemd is not that they have nice features - lots of things have nice features. Windows' Shadow Copies is a lovely feature that's a lot easier to configure that some alternative equivalents, etc.
It's that they put those nice features into some new paradigm of configuration when you could have just added them to the existing system.
'systemd' needs to stay optional, and I mean that explicitly. optional. Not "default", and not "optional, in the sense that you then have to do the maintainer's job for them because they are too lazy to consider people not using systemd, because systemd is the default, and the maintainer does not want to consider the people that dont want systemd, regardless of the reasons or circumstances." kind of way.
Systemd is potentially useful for only a subset of the linux ecosystem, and forcing this kind of change is a bad thing.
Please allow me to explain why:
Systemd seeks to be a "Be all, end all solution to system initialization", which ultimately means that it will itself try to cover every possible thing that its maintainers believe needs to or should happen during system init. That in and of itself means that it will be large and cumbersome; exactly the things that embedded linux should avoid, where ultra-minimalism is king. (We are talking systems that have just a few dozen megabytes of memory, and just a few hundred megahertz of processor power at the most. Having all that gobbled up by the init system as soon as power is applied is not going to win you any trophies, and boldly asserting that embedded devices need to obey a desktop paradigm is throwing the baby out with the bathwater.)
This is especially true with "reference distributions", like debian. Debian "console only" deployments with tools like debootstrap are reasonably common with embedded devices, as are deployments that make use of chroots for specific sandboxed services. A chroot does not need a full blown init like systemd. It is best served with a simple init script. Building a distro with the intention of killing simple init, and replacing it with a monolithic solution like systemd will make service daemons much more difficult to control in this way, and will actually rob core functionality away from the distro that goes that route--- exclusively in favor of desktop flavored deployments.
Linux is more than desktops.
Linux is routers.
Linux is home automation systems.
Linux is servers performing specialized functions.
Linux is so much more.
Please be more considerate about trying to force systemd into debian. Optional is OK. Optional like "gnome vs kde vs xfce vs $ManagerHere". Not "optional" like "unity on ubuntu". Debian is a reference distro, upon which many other distros are based. It has already found its niche in the linux ecosystem. Please dont try to reinvent it.
Maybe I'm unique in this regard, but as an admin, if something goes down on one of my servers, I want it to stay down until I intervene.
Firstly, if I'm properly monitoring the process, then I'll be alerted and can investigate.
Secondly, there may a *reason* the process goes down, and having it down may be a good thing. If someone's trying to fuzz our httpd process for exploitation, then it happily restarting will open up a wider attack window.
Autopilots on production servers seem like a bad idea to me.
Method of processing duck feet
In which case a nanny process restart is useless. Thanks for making my point, idiot.
Many hardware failures are transient, and a process restart is a very effective fix, at least in the short term. In the longer term, you'd better have monitoring in place so you know that the restarts are happening and can decide when to fix the hardware.
In addition, many process crashes are caused not by hardware failures, but by obscure software defects, and a process restart is not only effective at getting the production system back online, but arguably is a complete solution to the problem if the defect is sufficiently obscure that it's very rarely triggered, and hence not worth the large amount of effort required to identify and fix it.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
Maybe I'm unique in this regard, but as an admin, if something goes down on one of my servers, I want it to stay down until I intervene.
I have the opposite view. If something goes down:
1) I want to know about it. I want some monitoring system to send me an alert of some description.
2) I want it set up in a way that it won't clobber it's own log files. Preservation of the reason something failed is key.
3) I want it to automatically restart if possible. I say if possible because I want to avoid a re-start loop but if something goes down and comes back up then the end user is happy as uptime is maximised and providing criteria 1 and 2 are met I'm no worse off as an admin. Believe it or not random crashes may sometimes happen and may have nothing to do with the config or the system itself. I may be caused by some edge case that was hit by a user, and in those cases I am unlikely to find the problem quickly and in the interest of not limiting user access would be inclined to get the system up and running as quickly as possible and then sort through the log history into what the actual problem was afterwards anyway.
The reality is that before systemd showed up, there wasn't really any project with an active upstream that tried to solve the plumbing problem (I'm not talking about init in isolation here). Each distro had to invent their own hacks, some of them good, some of them not.
The fact is that the community that is beginning to form around systemd is much more healthy than the scattered bits and not-quite-fitting pieces we had before. Maybe that's sad, I don't know. I think that in the end, the unification around systemd will allow competitors to form (just implement the interesting subset of the systemd interface and you can integrate with all distros!). So long term we'll end up with a much more vibrant plumbing for Linux.