[openstack-dev] [Neutron] Question about bug 1314614

Sławek Kapłoński slawek at kaplonski.pl
Mon Mar 9 21:59:48 UTC 2015


Answears below

Dnia niedziela, 8 marca 2015 13:53:51 Ian Wells pisze:
> On 6 March 2015 at 13:16, Sławek Kapłoński <slawek at kaplonski.pl> wrote:
> > Hello,
> > 
> > Today I found bug https://bugs.launchpad.net/neutron/+bug/1314614 because
> > I
> > have such problem on my infra.
> (For reference, if you delete a port that a Nova is using - it just goes
> ahead and deletes the port from Neutron and leaves the VIF in an odd state,
> disconnected and referring to a port that no longer exists.)

I know and for me problem is that in such situation nova on some instance 
still have got some IP and neutron provide it to other vm because it is free 
in neutron's db.

> I saw that bug is "In progress" but change is abandoned quite long time
> > ago. I
> > was wondering is it possible that neutron will send notification to nova
> > that
> > such port was deleted in neutron? I know that in Juno neutron is sending
> > notifications to nova when port is UP on compute node so maybe same
> > mechanism
> > can be used to notify nova that port is no longer exists and nova should
> > delete it?
> What behaviour are you looking for?
I was thinking that maybe neutron can send notification to nova in such 
situation and nova can do "interface-detach" in that case.

> The patch associated with the bug falls attempts to stop deletion of used
> ports.  It falls far short of implementing consistent behaviour, which
> would have to take into account everything that used ports (including DHCP,
> L3, network services, etc.), it would probably need to add an 'in-use' flag
> to the port itself, and it changes the current API behaviour rather
> markedly.  We could go there but there's much more code to be written.

> Someone on the bug suggests removing the VIF from the instance if the port
> is deleted, but I don't think that's terribly practical - for some instance
> containers it would not be possible.
Ok, so if it is not possible for some containers, than I was wrong and idea 
about notification to nova is not good. I was using only kvm vms so for me 
such solution is possible I think.
> The current behaviour does seem to be consistent and logical, if perhaps
> unexpected and a bit rough around the edges.  I'm not sure orphaning and
> isolating a VIF is actually a bad thing if you know it's going to happen,
> though it needs to be clear from the non-Neutron side that the VIF is no
> longer bound to a port, which is where things seem to fall down right now.
I see only problem with IP assignment in such situation.

> I've also found no documentation about when delete should work and when it
> shouldn't, or what happens if the port is bound (the API and CLI document
> say that the operation 'deletes a port' and not much else).

Pozdrawiam / Best regards
Sławek Kapłoński
slawek at kaplonski.pl

More information about the OpenStack-dev mailing list