Comment 4 for bug 1333654

Reviewed: https://review.openstack.org/103865
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=4f8ccd7b95c27180a1cfe689e3c6f46bde5f803b
Submitter: Jenkins
Branch: master

commit 4f8ccd7b95c27180a1cfe689e3c6f46bde5f803b
Author: Salvatore Orlando <email address hidden>
Date: Mon Jun 30 16:29:32 2014 -0700

    Do not process events for instances without host

    In some cases Neutron might send events such as 'VIF unplugged'
    for instances which are either being deleted or shelved. When
    that happens there will be a failure in dispatching the event
    to the appropriate compute node - as there is no host for the
    instance.

    As multiple neutron events can be stashed in a single call
    it is important to avoid that this kind of errors will prevent
    processing of other events in the same call.

    This patch does not process events for instances without a host,
    marking them as failed.

    When the above condition occurs, the create event request will
    return a 207 response code. For specific events, a 422
    unprocessable entity code will be set.

    This patch also preserve the characteristic that events are
    returned in the response in the same order they were found in
    the request.

    Change-Id: I18062b81e50c722ec96b4296ac39384493683ae3
    Closes-Bug: #1333654