Re: initialization vs supervision

From: Alex Efros <powerman_at_powerman.name>
Date: Thu, 24 Jul 2014 04:49:48 +0300

Hi!

On Thu, Jul 24, 2014 at 01:42:19AM +0100, Laurent Bercot wrote:
> > Now granted some things are not able to be supervised such as udev on
> > my end. But honestly, does udev really require supervision?
> Yes, it does - why wouldn't it ? Or, if it doesn't, why would any
> other service ?

Any other service needed to keep system running and doing it's work, so I
didn't wanna wake up in the middle of the night just to start WEB or SQL
or EMAIL or DNS or CRON services if they've crashed. And I don't wanna lose
access to server if SSH or GETTY services crash and won't restart
automatically. But what's the point in bothering so much about udev?

udevd is only service started from /etc/runit/1. And, honestly, I think
it's much simpler to just kill it at end of /etc/runit/1 and (re-)start it
as a normal service when /etc/runit/2 will be executed, than try to
fork/delay parts of /etc/runit/1 - because most of other normal services
expect all parts of /etc/runit/1 already done before they'll start.

And I'll implement this right after udevd will crash for the first time.
Not because I think it's special and don't need supervision, but just
because I'm usually have other, more important things to do, than forcing
supervising to all and every service.

At a glance at pstree output there a lot of other things which isn't run
under runsv:

- mount.ntfs-3g
  * this one uses FUSE and it's started by mount command - is it makes
    sense or even possible to supervise it?

- usbhid-ups
  * not sure what's this - I'm running upsmon and upsd services, both
    live under runsv, probably someone of them has forked this process

- console-kit-daemon
- polkitd
  * I didn't run this crap, probably it was automatically started by dbus
    or some GUI apps

- gpg-agent
- ssh-agent
  * these was run from ~/.xinitrc because I needed to import ENV vars they
    provide - maybe it's possible to turn them into user-specific
    services, not sure

- dbus-launch
- dbus-daemon
- at-spi-bus-launcher
- at-spi2-registryd
  * I'm running dbus-daemon under runsv, and have no idea about these
    processes - probably they was either forked by supervised dbus-daemon
    or started by GUI apps

- gconfd-2
- xfconfd
  * I've no idea about these, also probably started by GUI apps

- compton
  * that's simple compositor for X11, started from ~/.xinitrc, probably
    can be supervised - but there are actually a lot of similar background
    apps started from ~/.xinitrc but didn't detached from their parent and
    thus didn't noticeable in pstree output - parcellite, xxkb, unclutter,
    conky, even goldendict or pidgin may be treat as "services" and run
    under supervision… if this makes any sense.

- pulseaudio
  * crap needed only for latest skype and started by it

So, how udevd is more important to supervise than all these apps/services?

-- 
			WBR, Alex.
Received on Thu Jul 24 2014 - 01:49:48 UTC

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