Comment 15 for bug 1662626

Reviewed: https://review.openstack.org/470387
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=017e853b950ddc10dab4ebab37e64cece40f274f
Submitter: Jenkins
Branch: stable/newton

commit 017e853b950ddc10dab4ebab37e64cece40f274f
Author: John Garbutt <email address hidden>
Date: Tue Feb 7 19:12:50 2017 +0000

    Stop failed live-migrates getting stuck migrating

    When there are failures in driver.cleanup, we are seeing live-migrations
    that get stuck in the live-migrating state. While there has been a patch
    to stop the cause listed in the bug this closes, there are other
    failures (such as a token timeout when talking to cinder or neutron)
    that could trigger this same failure mode.

    When we hit an error this late in live-migration, it should be a very
    rare event, so its best to just put the instance and migration into an
    error state, and help alert both the operator and API user to the
    failure that has occurred.

    For backport into Newton, 'migrate_instance_start' had to be patched
    in the unit test (nova/tests/unit/compute/test_compute.py).

    Closes-Bug: #1662626

    Change-Id: Idfdce9e7dd8106af01db0358ada15737cb846395
    (cherry picked from commit b56f8fc2d1392f4675a5baae0977e4817a362159)
    (cherry picked from commit 012fa9353ff18d3d52120fd42a2ec25dbc5a02b7)