[pkg-ntp-maintainers] Bug#683061: Bug#683061: ntp: diff for NMU version 1:4.2.6.p5+dfsg-2.1

[Kurt Roeckx]

severity 683061 normal
thanks

On Tue, Aug 28, 2012 at 08:34:46AM +0200, Helmut Grohne wrote:
> Control: severity 683061 serious

Please don't change the severity without my permission.

There are existing bugs to relevant software already about how
they misbehave where I know about it.

> On Sun, Aug 26, 2012 at 10:20:16PM +0200, Kurt Roeckx wrote:
> > Ntp should work correctly if nothing else is broken about
> > the dns setup.
> 
> Please clarify this. If the DNS server does not respond to queries,
> because it is only started after ntp, does that constitute a breakage in
> the DNS server?

Not responding is fine, responding with a temporary error is also
fine.  Responding with an error indicating the hostname does not
exist is not fine.  And I've seen way too many cases where ntpd
gets as answer that the hostname does not exist.

> If ntp then fails to resolve debian.pool.ntp.org and
> fails to repeat that atfer the DNS server is started thus failing to
> synchronize time at all, is that a bug in ntp?

Does ntpd report anything in the log files?

If ntpd gets back that the hostname does not exist, I think it shouldn't
keep trying for ever to try and resolv it.  I would argue that it
had a bug in that case.

> Another way to resolve this issue would be adding $named to Should-Start
> (instead of Required-Start). Would that be something you can live with?

Required-Start is fine.  But it won't solve your problem.  It
might just make it more likely or unlikely that someone sees a
problem.

I will make the change to put it in Required-Start, but that's
not what this bug is really about.

Note that dns happens over udp, it's expected that packets might
not reach the server and that you need to retry.

What does your /etc/nsswitch.conf say for hosts?

Can you reproduce this problem with the server normally started
but unbound stopped?

Can you strace ntpd and see what it gets from getaddrinfo()?


Kurt