On Thu, 07 Mar 2013 08:42:41 -0500
Stephen Gallagher <sgallagh(a)redhat.com> wrote:
>> So yes, we *could* build a scheduling provider, but I think
we
>> want to think very hard about what level of scheduling we want to
>> support. systemd's scheduler is a very large superset of what
>> cron is capable of, so I suppose we could build that first and
>> then extend it later to support the advanced systemd features.
>
> Starting with cron would also have the advantage of building the
> most portable code first; it would make sense to add the more
> version-specific options later.
>
While I agree with that in principal, I need to make the point that
I'm not sure we can build a CIM model for cron that will extend to the
systemd approach at all. They may ultimately need to be two separate
models, at which point we'll need to figure out how to manage the
transition (which is what OpenLMI is trying to avoid).
Cron might be an interesting modelling exercise... There are user crontabs,
scripts in /etc/cron.{hourly,weekly,monthly}, package-specific crontabs
in /etc/cron.d, system-wide /etc/crontab. And we might want to model and
monitor the running/finished jobs as well. I admit I don't know much about
systemd timer units. However I suppose systemd might make it easier to find
logs of a particular job run at least (and this would be a required feature I
assume).
I'm only afraid that both the cron and systemd are config-files driven and we
probably won't avoid parsing/editing the files. Which is ugly.
Regards,
--
Tomáš Smetana
Platform Engineering, Red Hat