Open Stack

On Wed, Jan 27, 2016 at 4:10 PM, Sean M. Collins <sean at coreitpro.com> wrote:
> Hi,
>
> I started poking a bit at https://bugs.launchpad.net/devstack/+bug/1535661
>
> We have radvd processes that the l3 agent launches, and if the l3 agent
> is terminated these radvd processes continue to run. I think we should
> probably terminate them when the l3 agent is terminated, like if we are
> in DevStack and doing an unstack.sh[1]. There's a fix on the DevStack
> side but I'm waffling a bit on if it's the right thing to do or not[2].
>
> The only concern I have is if there are situations where the l3 agent
> terminates, but we don't want data plane disruption. For example, if
> something goes wrong and the L3 agent dies, if the OS will be sending a
> SIGABRT (which my WIP patch doesn't catch[3] and radvd would continue to run) or if a
> SIGTERM is issued, or worse, an OOM event occurs (I think thats a
> SIGTERM too?) and you get an outage.

RDO systemd init script for the L3 agent will send a signal 15 when
'systemctl restart neutron-l3-agent' is executed. I assume
Debian/Ubuntu do the same. It is imperative that agent restarts do not
cause data plane interruption. This has been the case for the L3 agent
for a while, and recently for the OVS agent. There's a difference
between an uninstallation (unstack.sh) and an agent restart/upgrade,
let's keep it that way :)

>
> [1]: https://github.com/openstack-dev/devstack/blob/master/lib/neutron-legacy#L767
>
> [2]: https://review.openstack.org/269560
>
> [3]: https://review.openstack.org/273228
> --
> Sean M. Collins
>
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev