From 012fa9353ff18d3d52120fd42a2ec25dbc5a02b7 Mon Sep 17 00:00:00 2001 From: John Garbutt Date: Tue, 7 Feb 2017 19:12:50 +0000 Subject: [PATCH] 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. Closes-Bug: #1662626 Change-Id: Idfdce9e7dd8106af01db0358ada15737cb846395 (cherry picked from commit b56f8fc2d1392f4675a5baae0977e4817a362159) --- nova/compute/manager.py | 10 ++++-- nova/tests/unit/compute/test_compute.py | 43 +++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 3 deletions(-) diff --git a/nova/compute/manager.py b/nova/compute/manager.py index c019715903a4..ed58725df3c7 100644 --- a/nova/compute/manager.py +++ b/nova/compute/manager.py @@ -5396,12 +5396,16 @@ class ComputeManager(manager.Manager): self._rollback_live_migration, block_migration, migrate_data) except Exception: - # Executing live migration - # live_migration might raises exceptions, but - # nothing must be recovered in this version. LOG.exception(_LE('Live migration failed.'), instance=instance) with excutils.save_and_reraise_exception(): + # Put instance and migration into error state, + # as its almost certainly too late to rollback self._set_migration_status(migration, 'error') + # first refresh instance as it may have got updated by + # post_live_migration_at_destination + instance.refresh() + self._set_instance_obj_error_state(context, instance, + clean_task_state=True) @wrap_exception() @wrap_instance_event(prefix='compute') diff --git a/nova/tests/unit/compute/test_compute.py b/nova/tests/unit/compute/test_compute.py index daffcf199fac..7db8964f423f 100644 --- a/nova/tests/unit/compute/test_compute.py +++ b/nova/tests/unit/compute/test_compute.py @@ -5961,6 +5961,49 @@ class ComputeTestCase(BaseTestCase): mock_post.assert_called_once_with(c, instance, False, dest) mock_clear.assert_called_once_with(mock.ANY) + @mock.patch.object(compute_rpcapi.ComputeAPI, 'pre_live_migration') + @mock.patch.object(compute_rpcapi.ComputeAPI, + 'post_live_migration_at_destination') + @mock.patch.object(compute_manager.InstanceEvents, + 'clear_events_for_instance') + @mock.patch.object(compute_utils, 'EventReporter') + @mock.patch('nova.objects.Migration.save') + def test_live_migration_handles_errors_correctly(self, mock_save, + mock_event, mock_clear, mock_post, mock_pre): + # Confirm live_migration() works as expected correctly. + # creating instance testdata + c = context.get_admin_context() + instance = self._create_fake_instance_obj(context=c) + instance.host = self.compute.host + dest = 'desthost' + + migrate_data = migrate_data_obj.LibvirtLiveMigrateData( + is_shared_instance_path=False, + is_shared_block_storage=False) + mock_pre.return_value = migrate_data + + # start test + migration = objects.Migration() + with mock.patch.object(self.compute.driver, + 'cleanup') as mock_cleanup: + mock_cleanup.side_effect = test.TestingException + + self.assertRaises(test.TestingException, + self.compute.live_migration, + c, dest, instance, False, migration, migrate_data) + + # ensure we have updated the instance and migration objects + self.assertEqual(vm_states.ERROR, instance.vm_state) + self.assertIsNone(instance.task_state) + self.assertEqual("error", migration.status) + + mock_pre.assert_called_once_with(c, instance, False, None, + dest, migrate_data) + self.assertEqual(0, mock_clear.call_count) + + # cleanup + instance.destroy() + @mock.patch.object(fake.FakeDriver, 'unfilter_instance') @mock.patch.object(compute_rpcapi.ComputeAPI, 'post_live_migration_at_destination')