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Replacing the Aging Init Procedure on Linux
SmellsLikeTeenGarlic writes "Seth Nickell (of Storage and Gnome HIG fame) has started a new project which aims to replace the aging Init system on Linux. OSNews has more details on the project, directly from Seth. The new Python-based approach will make booting faster and it will talk to the D-BUS daemon, freedesktop.org's leading project. And speaking of freedesktop.org, it is important to mention the release of HAL 0.1, an implementation of a hardware abstraction layer for KDE, XFce and Gnome, based on a proposal by freedesktop.org's founder Havoc Pennington and being implemented by David Zeuthen. It is innovative projects like Storage, SystemServices and HAL that can bring the kind of integration to the underlying system that current X11 desktop environments lack."
I like python a lot, but why make it a requirement for init ? Just means more stuff has to be installed fort he default system to work. I prefer to sue the base shell.
SystemServices is not at all tied to Gnome. It will probably not require much more than the kernel and Python. His goal is partly to make a nice set of APIs callable from a desktop like Gnome to ease with management and error reporting. This project is not tightly integrated with Gnome just because someone from Gnome has started it.
Developers: We can use your help.
As far as "most" sysadmins not understanding run levels, he's out of his mind. Maybe he doesn't get it, but it's a long standing thing that works well. In fact, it works SO well, that Linux adopted it from System V after using the older monolithic rc scripts for a long while.
7 November 2006: The day Americans realized corruption and incompetence weren't addressing 11 September 2001
His approach isn't very *nix-ish, it is very Windows-ish. It assumes you have a GUI. It relies on a large complex framework of interfaces. It assumes you have Python scripting. This may work very well for many desktop distros, but it can't become some great unifying thing like he wants, since he chose dependencies that are not the least common denominator. I believe that his goals can all be achieved with minor changes to the existing init system, rather than a megalithic rewrite.
This approach sounds like he is trying to push some specific technologies he is interested in, and so he decided a new init system that uses them would be a nice PR way to push them.
So I skimmed through the D-BUS spec and, as I expected, they are simply reinventing CORBA.
When will Open Source developers figure out that just because the OS community didn't come up with a technology, doesn't mean it has to be re-written with fewer features?
I gaurantee that whatever aspects of CORBA the D-BUS developers found unnacceptable - complexity, overhead - will be reintroduced into D-BUS by the time it reaches maturity. That's just how these things go - someone decides that Standard X is "cool, but too complicated", and then five years later they realize that their solution has become just as complicated as Standard X because, lo and behold, all that complexity was there for a reason. Real-world solutions never stay simple, because real-world problems aren't simple.
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CPAN rules. - Guido van Rossum
If someone comes up with a whizbang new boot system. great. Just make sure that if something goes wrong, or something needs to be changed, it's:
I don't want some horrific equivalent of the Windows Registry lurking in the background. There should be no mysteries about what gets started and when. I'm not a Windows guru, so maybe this stuff is easy to determine in XP or Server 2003, but I've always found plain ol' text files to be much easier to deal with than fancy-dancy databases. Or at least compile the databases from plain ol' text files.
I think Seth's idea is a good one. Of course, there are some things to refine: the dependency shouldn't be external (e.g. SystemService knowing the dependancy tree) but dynamic (e.g. GDM sees that its config requires network login, so it asks SystemService to start network), etc.
But overall rethinking the init is a good thing. Even just opening the debate is a very good thing. The mess of shell scripts is more a giant hack than a well-thought bootstrap system.
As an old school programner let me say I do not hate Python. I just do not know it. So far I have found noting about Python that makes me want to take the time to learn it.
I do tell people just learning to program that it sounds like a good first language.
For internal programming that requires a GUI I tend to use Java. Netbeans is just too good of an IDDE to give up.
For non-gui internal programs I tend to use Perl. Why perl over Python? I know Perl.
For programs that end up in the hands of our customers I use C++.
I really doubt that Python sucks. I have seen too many really good programs written in it.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Unices are being deployed across more and more diverse kinds of systems, and dependencies on python and d-bus, both of which projects I support in themselves, are not going to be welcome in the init of the majority of unix systems today, especially in servers or embedded systems.
This still won't stop the GNU folks from fucking it up, though, because more dependencies ensure GPL-lock-in (you didn't think it could happen to us, too, did you?). This isn't a troll, but a very serious issue, where lots of software is becoming very GNU-specific rather than UNIX-specific (I hope everyone can see this distinction).
Healthcare article at Kuro5hin
Apparently freedesktop.org has devolved from a desktop standards initiative to a home of pointless wheel-reinvention. Here's a list of the projects listed above, followed by their existing, more mature counterparts:
Init Replacements: simpleinit, minit, jinit, runit, daemontools, serel. Progeny also has their own system based on Gooch's need/provide architecture.
D-BUS: CORBA
HAL: Discover
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CPAN rules. - Guido van Rossum
SystemServices: Hardly wheel re-invention. If you read the linked-to article you'll find that none of the listed "init replacements" address any of my four major goals. They addressed their own goals, which are nice ones I'm sure, but not things that the desktop needs. In fact, the only thing they really add over init that's interesting to me is a dependency system + parallelization. And RH's internal work on init scripts has suggested this results in only small improvements (neighborhood of 30% I believe) in boot time... which is better but not dramatic. Dependency systems are pretty trivial to implement and a dime a dozen, in any case.
DBus: yeah, its a lot like CORBA. Its even more like KDE's DCOP. In fact, its a lot like DCOP. You could even think of it as a major iteration of DCOP. So look, GNOME has been using CORBA for IPC for several years and its still something people avoid using whenever possible. KDE used CORBA for a while, and even with the comparatively nice CORBA/C++ bindings found KDE devs avoided it when possible. CORBA is a freaking PITA to use for lightweight desktop-style stuff. DCOP was the solution (its a good solution, GNOME should have done this ages ago): make it easy enough to use that developers will actually readily communicate over DCOP. Communication protocols have no inherent value on their own. They acquire value when there's things to talk to. Developers won't use the API unless its simple. You can write very simple comm layers for KDE and GNOME around DBUS. Even if we GNOME folk wanted to use CORBA (we don't), KDE wouldn't, and a requirement for DBus being truly useful is that KDE+GNOME have to be willing to use it. End of story.
HAL: I'm not really familiar with discover, so I'm not going to shoot my mouth off (much *grin*). From ransacking the web page you linked to, it doesn't look like discover really supports the sort of "central daemon with notification signals" model that we need to provide good hardware support on the desktop side. Without that... its sort of useless to us. It looks a lot like Kudzu, which is a good thing (and trust me, Havoc who proposed HAL in the first place knows about Kudzu, and probably discover) but it simply isn't what those of us who are in the ditches writing this desktop code need.
Moral of the story: a superficially similar "solution" does not necessarily address the issues that we as desktop developers face. We propose these things because we have concrete problems to solve. Sometimes the problems are not obvious until you try to do something and end up butting into them. We're lazy people, just like anyone, and we don't like :-)
This is what is great about Open Source - people can innovate, create new systems, and if they prove to be good, they can be widely deployed. That's how progress happens, and the heart of a developer rejoices on seeing things like this. In the end, superior technology will triumph, and seeing that he is using Python, he is already well on his way :-).
And as for all of you sticking to the old stuff, because it's good enough: are you sure you are not just getting old? The time I start to whine about progress ("the old way was good enough") will be a sad day indeed. Or perhaps this is the difference between sysadmin-types and programmer-type: sysadmins like to stick to old shell script based system because it's uniquity, while developers see the opportunities of new technologies and have a certain inborn respect for technological superiority.
Linux will evolve, live with it. If the old system is indeed better, it will be used indefinitely, but unless we try something different, we will never know. Having some distros doing the thing in an alternative way is a good way to hash this out.
I for one welcome our new freedesktop.org overlords. I'm really liking the direction that Havoc Pennington and other Gnome-related people are taking as far as desktop things go. We need more dynamic & motivated people like them on powerful positions.
Save your wrists today - switch to Dvorak
Reminds me of an old story of somebody hired to improve the elevator waiting time that people had been complaining about. Instead of tinkering with elevator algorithms or making it run faster, he simply installed mirrors by the elevator. Nobody complained anymore.
It makes a difference, because it's something I'm waiting for. It's one more minute before I can read email, or search for something on Google, or whatever I turned on the computer to do.
An extra three minutes shutting down, on the other hand, isn't that important for a desktop, because I would probably have walked away to do something else. It might be for a laptop, however, because the user might be waiting to unplug it, etc.
The point is, it's not the amount of time, but whether I'm waiting for it or not. This means that one solution to the problem may simply be downloading Slashdot headlines and showing them while the system boots.
Ok, so I'm not the best person to say this because anyone who looks for my publishing credits will immediately realize that I'm a "Perl guy" and thus, I must hate Python (I'm not really a Perl guy, and I don't hate Python, but that's beside the point). I'll go on anyway because this is important, and folks who don't do sysadmin for a living may not have had to think about this.
init itself is so lightweight and small that it rarely, if ever, fails. This is a good thing, since it's init's job to start a ton of very heavy-weight services.
That said, I see the logic in bloating init with some of the features that are almost always implemented in a distribution built around it. For example, it would be nice to see init perform some service tracking such that it could be told directly to kill a service, and it could do so.
Keep in mind that every time you increase the size of init, you remove a class of systems that can now no longer use it because of it's footprint. This matters a lot for some kinds of embeded systems that have just enough brains (that is, RAM and installed libraries/software) that it makes sense to have init today.
You certainly could not achieve this minimal-growth by re-coding init in Python, Java, Perl, Lisp or any other high-level language. That's not a slam against high-level languages, it's a simple fact of life that their flexibility comes with costs.
As for the shell-script init-scripts, I certainly feel that all of that should be moved out of init's domain. Each application should have a control program (like apachectl) which knows how to start it, stop it, get status, reload configs, etc. That program can be written in C for speed; a high-level, general purpose language for ease of maintenance; or even in shell. But, the point is that that should not be a constraint of init.
init, might well provide a library and/or command-line tools to make writing those controlers easier and more modular, but I don't think there should be any REQUIREMENT that your program know anything more than the calling conventions of an "init controler". The more constraints you heap on, the less software is going to ship ready to integrate with your init system, and that way lies far too much integration work to create a workable OS (and thus MORE variants between distributions, not less).
Once you've done all of that, THEN you can think about the high-level glue so that things like a desktop integrate better.
Whoa an AC with some insight. Windows 2000 had a single-threaded boot, kind of like Linux. Load things one by one and in order. Win XP came out with a multithreaded boot process, which brings the system up faster. However it only appears to be ready sooner, it takes the same amount of time to get into a usable state.
Can I get an eye poke?
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