Re: `s6-svc -o -wD` doesn't wait for service to go down

From: Max Ivanov <ivanov.maxim_at_gmail.com>
Date: Fri, 20 May 2016 15:11:27 +0100

That is what I ended up doing, but without an `-wu` part, thanks for the tip.

What concerned me at first is that s6-svwait page explicitly states
that "s6-svwait only waits for notifications; it never polls.", which
might mean that if service went down before s6-svwait started, then it
can't wait forever for "down" notification. I then checked with two
consecutive `s6-svwait -D` calls and both detected that service
already down and exited, so s6-svwait is actually level-triggered, not
edge triggered.

On 20 May 2016 at 15:00, Laurent Bercot <ska-supervision_at_skarnet.org> wrote:
> On 20/05/2016 13:28, Max Ivanov wrote:
>>
>> Hi All,
>>
>> is it a bug or design decision that when requesting service to go up,
>> s6-svc can't wait for service to go down?
>
>
> Design decision. You can't wait for the service to go down at this
> point because it is *already* down, so the "wait for it to be down" part
> immediately succeeds. What you are trying to do is wait for the service
> to go down _after it has gone up_.
>
>
>> For instance `s6-svc -o -wD` exits without waiting for `finish`
>> script to execute.
>
>
> Try "s6-svc -o -wu service ; s6-svwait -D service". That should do what
> you want.
>
> --
> Laurent
Received on Fri May 20 2016 - 14:11:27 UTC