[systemd-devel] start / stop daemon

[Mantas Mikulėnas]

On Tue, Aug 19, 2014 at 5:44 PM, Bonno Bloksma <b.bloksma at tio.nl> wrote:
> Hi,
>
>>> I do not know whether this is something systemd should handle or if it is something that belongs to the kernel, so let me ask this first:
>>>
>>> Is starting and stopping a daemon part of something systemd is / becomes responsible for?
>>
>> Well, yes, starting & stopping daemons is pretty much the *primary
>> function* of systemd; it's part of the job of being an init system.
>> (Although the old SysVinit would rather delegate this to
>> shellscripts.)
>>
>> The kernel still manages individual processes (fork/exec/exit), of course; but it's not the kernel's job to care about what is a 'daemon'
>> nor what daemons should be started & when.
>
> In that case I would like to ask if the developers have already considered a development in the Windows world considering the stopping of services that may take a LOOONG time stopping, for instance some databases.
>
> I wonder if the people developing systemd are paying attention to a development in de Windows environment where the latest thing is that de service can report back that it is indeed still trying to stop and not just hung or not reporting back. Windows will now kill a service after a certain time when shutting down, in some cases it is killing a database that took A LONG TIME to shut down and cause the database to become inconsistent. The new development is to make sure that does not happen.
> If systemd is trying to become smart about stopping services it might be a good idea to have this built in. Also not just have the service report back "I am still busy" but also with a progress indicator which NEEDS to increase at each report so systemd can detect whether the service is indeed progressing towards a stopped state or hung in the getting there.
> From the past I have seen things go wrong in communication when the only thing reported back is "I am busy" while there was no progress being made toward the finish.
>
> Is this something the systemd team has already put on the todo list or am I the first to suggest it?

Possibly:

http://thread.gmane.org/gmane.comp.sysutils.systemd.devel/21419

http://article.gmane.org/gmane.comp.sysutils.systemd.devel/21997

"Introducing sd_notify() messages that can notify PID 1 about daemons
reloading or shutting down, has been on the TODO list for a while"

-- 
Mantas Mikulėnas <grawity at gmail.com>