Re: How Unix manages processes in userland

[David Holland <dholland-tech%netbsd.org@localhost>]

On Sun, Dec 08, 2013 at 02:34:59PM -0800, John Nemeth wrote:
 > }  >      What infrastructure?  We don't do service management.  Our
 > }  > rc.d startup code does not count as service management.
 > } 
 > } It is what we have and it handles dependencies, starting and stopping;
 > } regardless of whether it's adequate as it is, bolting on something
 > } else that doesn't interoperate with it would be a serious mistake.
 > 
 >      A proper service management facility would replace it.  The
 > only real question is would things like rc.conf be kept (rc.d files
 > might be used for dependency information, but generally aren't
 > suitable for real service management).

Yes, and if the question is: rework it, or throw it out and replace it
with something totally different and incompatible; then I'd rather
rework it. This is not a NIH response so much as a recognition of the
difficulties associated with migrating deployed systems.

Also, while your attention is still on this, please describe what
you'd consider the properties of a "proper service management
facility" to be. I haven't seen this Solaris thing you referenced
(thankfully the last time I had to deal with administering Solaris was
more than ten years ago) but I have seen various other things, most of
which seem like badly conceived bolt-ons to sysvinit.

 >      On that score, I disagree with the idea that service management
 > should be a plug-in where one can drop in any number of different
 > service monitors.

If you're going to be monitoring whether a service is working, rather
than merely running, you need to be able to supply custom monitoring;
local problems and local configuration often cause local problems that
need this. But I don't see this as a problem.

However, what I think you mean is that the general monitoring scheme
and framework has to be designed in and not an afterthought -- that I
agree with and that was my point that Mouse misunderstood about
"bolted on".

-- 
David A. Holland
dholland%netbsd.org@localhost