Comment 21 for bug 1662626

Reviewed: https://review.openstack.org/508640
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a0525f650af1fa763eb7e58185644f9e7fe1a3dd
Submitter: Zuul
Branch: stable/ocata

commit a0525f650af1fa763eb7e58185644f9e7fe1a3dd
Author: John Garbutt <email address hidden>
Date: Tue Feb 7 18:55:26 2017 +0000

    Stop _undefine_domain erroring if domain not found

    During live-migration stress testing we are seeing the following log:
    Error from libvirt during undefine. Code=42 Error=Domain not found

    There appears to be a race while trying to undefine the domain, and
    something else is possibly also doing some kind of clean up. While this
    does paper over that race, it stops otherwise completed live-migrations
    from failing. It also matches similar error handling done for when
    deleting the domain.

    The next part of the bug fix is to ensure if we have any similar
    unexpected errors during this later phase of the live-migration we don't
    leave the instance stuck in the migrating state, it should move to an
    ERROR state. This is covered in a follow on patch.

    Partial-Bug: #1662626

    Change-Id: I23ed9819061bfa436b12180110666c5b8c3e0f70
    (cherry picked from commit b706155888d740841d745c52aae543cf82fab0bc)