Comment 6 for bug 1821058

Reviewed: https://review.opendev.org/645173
Committed: https://git.openstack.org/cgit/openstack/neutron-specs/commit/?id=fde298d0a179987a4195c8e12a66a2aa968ddfb6
Submitter: Zuul
Branch: master

commit fde298d0a179987a4195c8e12a66a2aa968ddfb6
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Thu Mar 21 13:39:13 2019 +0000

    Port binding event extended information for Nova

    There are several cases in the Nova/Neutron/os-vif interaction
    where the knowledge of the neutron core plugin or ML2 driver
    would be useful to facilitate a more robust handling of guest
    networking.

    For example, in Icehouse, a external event mechanism was
    introduced to allow neutron to notify Nova of network changes
    and VIF plugging. As the occasion on which these events are
    emitted is dependent on the driver that bound the port and Nova
    does not have knowledge of that. Therefore, Nova cannot rely on
    the event to synchronize the operation between Nova and neutron,
    which has lead to a race condition in the past.

    Change-Id: I57f4df31bee83b818f2c0123577d11a8e07c0191
    Related-Bug: #1821058