Re: interesting claims

["Laurent Bercot" <ska-supervision@skarnet.org>]

>So Laurent's words from http://skarnet.org/software/s6/ were just part
>of a very minor family quarrel, not a big deal, and nothing to get
>worked up over.

  This very minor family quarrel is the whole difference between having
and not having a 100% reliable system, which is the whole point of
supervision.

  Yes, obviously sinit and ewontfix init are greatly superior to
systemd, sysvinit or what have you. That is a low bar to clear. And
the day we're happy with low bars is the day we start getting
complacent and writing mediocre software.

  Also, you are misrepresenting my position - this is not the first
time, and it's not the first time I'm asking you to do better.
I've never said that the supervision had to be done by pid 1, actually
I insist on the exact opposite: the supervisor *does not* have to
be pid 1. What I am saying, however, is that pid 1 must supervise
*at least one process*, which is a very different thing.

  s6-svscan is not a supervisor. It can supervise s6-supervise
processes, yes - that's a part of being suitable as pid 1 - but it's
not the same as being able to supervise any daemon, which is much
harder because "any daemon" is not a known quantity.
  Supervising a process you control is simple; supervising a process
you don't know the behaviour of, which is what the job of a
"supervisor" is, is more complex.

  In future presentations, I will make sure to pinpoint the difference.
Yes, that is a detail, but this detail is what allows us to make
pid 1 both simple (not having the whole supervision logic in pid 1)
and correct (covering the case where all processes die).

--
  Laurent