Thursday 13 May 2021

Re: Packaging policy discussion: After=network-online.target

On Fri, May 14, 2021 at 10:07:39AM +1000, Christopher James Halse Rogers wrote:
> > However, I still have the same question - what if network connectivity
> > drops & gets re-established? Should we bounce the
> > network-online.target (aka restart it)? We can declare for units to be
> > restarted, when network-online.target is restarted, if they otherwise
> > themselves are incapable to dynamically detect networking loss &
> > networking resumption.

> Hah! I've actually received a reply off-list relevant to this. They found
> network-online.target to be unreliable for nfs & xdmcp. Apparently because
> of the spanning tree search by their network switches the interface would be
> briefly available, activating relevant systemd unit dependencies, then not
> work for about 25 seconds.

Unreliable for an NFS *server*? Because having the network be
intermittently unavailable after start should not prevent the nfs server
from talking to the local resolver, and for that resolver to try a few times
to contact the upstream DNS servers for a response. (If the network switch
was actually taking the port back down while doing STP, and therefore the
host lost its route because the interface was down, that would be a
problem... but er, that's a broken thing for a switch to do?)

--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
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