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Re: upstart: please update to latest upstream version



On Sun, Feb 26, 2012 at 17:24, Goswin von Brederlow <goswin-v-b@web.de> wrote:
> Maybe the solution isn't event base or dependency based. Maybe the
> right solution is event based and dependency based.

In one sense this is obviously right.  Any solution has to respond to
various kinds of events and has to be able to serialize multiple
activities that need to be serialized.

Both Upstart and systemd do both of these things.

Upstart provides event-oriented plumbing which can be used to do very
many interesting things, almost all of which are wrong. The right ones
are listed in the Upstart Intro, Cookbook and Best Practises.

It looks as if systemd takes the approach of hard-coding "all" the
right ones so that the user only has to choose which thing is right
for his program.  Systemd hides the event handling so the user doesn't
have to think about them; she only has to think about the states.  She
has to think about states because dependencies are between states,
e.g., her web application Foo's reqiurement that database Bar be
running.

If either Upstart or systemd (but not both) turns out to have a
fundamental design flaw such that it cannot fulfill some important
process management requirement, then that will make it easy for us to
choose between them.

But I haven't seen evidence that either one has such a flaw.  So, the
choice will be difficult because it has to be made by weighing many
different and almost incommensurable pros and cons.
-- 
Thomas


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