supervision - discussion about system services, daemon supervision, init, runlevel management, and tools such as s6 and runit
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From: Gerrit Pape <pape@smarden.org>
Subject: Re: svwaitup != sv start
Date: Thu, 4 May 2006 07:10:44 +0000	[thread overview]
Message-ID: <20060504071044.20938.qmail@c76e844cce5dae.315fe32.mid.smarden.org> (raw)
In-Reply-To: <20060406201647.GB19589@home.power>

On Thu, Apr 06, 2006 at 11:16:47PM +0300, Alex Efros wrote:
> I found some differences between `svwaitup` logic and `sv start`:
> 
> 1)  I don't see a way how to "wait until service will be up and running
>     for at least X seconds". This lead to race condition error, for example
>     if we have this in /service/getty-tty5/run:
>         #!/bin/sh
> 	/etc/setfont tty5
> 	exit
> 	exec /sbin/agetty 38400 tty5 linux
>     and then will run `sv start getty-tty5` a couple of times we will see
>     some success and some failures.

The sv program utilizes the ./check script in service directories for
this purpose.  After all it's always a race condition, the service
daemon can terminate just at the time it is considered to be up and
running, and reported so.

> 2)  If ./finish is running now, `sv start` will report service as running,
>     but this is wrong. (I've "sleep 3" in ./finish for XWindow service, to
>     prevent X from restarting too fast.)

I've fixed that in 1.5.0.

> Any ideas how to use `sv start` to make it as reliable as `svwaitup` was?

I suggest to try to provide an appropriate ./check script for this
service.

Thanks, Gerrit.


      reply	other threads:[~2006-05-04  7:10 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-04-06 20:16 Alex Efros
2006-05-04  7:10 ` Gerrit Pape [this message]

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