Re: runsvdir killed

[Gerrit Pape <pape@smarden.org>]

On Sat, Nov 06, 2004 at 08:42:16PM +0200, Alex Efros wrote:
> Sometimes when I check `ps axf` I see no runsvdir process, and all `runsv`
> processes has no parent (or their parent is process N1: runit-init).
> 
> I think I know what happens - kernel has killed runsvdir because of 'out of
> memory' error (a lot of complex perl scripts earn all memory). Of course,
> kernel has killed not only runsvdir, but also it try to kill that perl
> scripts, mysql, etc. But this isn't a problem - perl scripts will be
> restarted by cron, mysql will be restarted by runsv, etc... but who will
> restart runsv if runsvdir is killed and runsv reparented (I not sure is this
> a correct english term) by runit-init?

The runit program running as process 1 monitors the stage 2 which by
default is the runsvdir process.  If runsvdir, and so /etc/runit/2,
crashes or exits 111, runit restarts /etc/runit/2.  If it exits 0, runit
enters stage 3 and runs /etc/runit/3; see the runit(8) man page.  Either
of them should happen on your system if /etc/runit/2 is terminated.

> So, the question is: how to restore killed runsvdir without reboot?  And the
> second question: I suppose killing runsvdir mean exiting stage2 and entering
> stage3 for reboot/halt... is this correct? And if this correct why this may
> not happens in my case?

You can send the runsvdir process a HUP signal to have stage 2
restarted, but this should almost never be needed.

> P.S. Yeah, I know, perl scripts eating all memory and kernel starting
> killing processes isn't correct behaviour for server. But for now I've no
> idea why this happens, so I can't fix it. On that server I got kernel
> oops/panic every 12-72 hours, and I've not found any information about these
[...]
This sounds really broken.

Regards, Gerrit.