F15 Feature - convert as many service init files as possible to the native SystemD services

[Marcela Mašláňová]

On 11/26/2010 01:27 AM, Lennart Poettering wrote:
> On Thu, 25.11.10 17:33, Tomas Mraz (tmraz at redhat.com) wrote:
>
>>> Actually it's true, but in the near future all standard cron jobs
>>> might be runned by systemd
>>>
>>> http://0pointer.de/public/systemd-man/systemd.timer.html
>>>
>>> It's not 100 % cron replacement now, but who knows what the future holds :)
>> To add some argument to my previous sarcasm. I do not think that it
>> makes any sense to replicate cron functionality in systemd. Either you
>> replicate half of it and then you still need to run crond for the rest
>> or you replicate it completely. But in that case what is the saving over
>> the separate daemon? I'm sorry but I do not think that crond is anything
>> that "optimized out" by inclusion can improve performance of Linux
>> desktop/server/whatever. I do not say that cronie code cannot be
>> improved - it definitely can - but it does not make any sense to
>> reimplement it from scratch.
> crond is not particularly complex. And providing similar functionality
> in systemd is relatively easy as the more complicated stuff cron does is
> actually spawning the processes, and systemd is vastly more powerful
> with that. i.e. you can set IO/CPU schedulers, get sane logging, get all
> the cgroups niftyness, you can pull in extra deps, yadda yadda.
>
> Also, what's particularly interesting is that you can combine various
> triggers if you do this in systemd: i.e. have one timer-based trigger,
> and one inotify trigger (i.e. .path unit), and they start the same job,
> and you don't end up with duplicates and need locking. 
>
> And also, cron does a couple of really nasty things. For example it
> wakes up in regular intervals to check if a job is ready to run. It does
> so to deal with wallclock time changes/suspends. In systemd we are
> working on a different way to solve this, so that we can actually sleep
> as long as possible, and don't have to wake up in regular
> intervals. Also, this means we can have much more accurate time
> specifications, and we don't have to pay a price for it, due to
> this. This different design will even allow us to do amazing stuff that
> hasn't existed so far, for example, mark cron jobs so that they wake up
> the machine from suspend, and similar.
>
Cronie is using inotify, so it doesn't wake every minute as it used to.

I'm just curious, how many programmes would stay in Fedora after
you finish systemd ;-) </sarcasm>.

Marcela

-- 
Marcela Mašláňová
BaseOS team Brno