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Merge "compute: refactor volume bdm rollback error handling" into stable/stein

tags/19.3.1
Zuul 3 weeks ago
committed by Gerrit Code Review
parent
commit
ad99aa5164
2 changed files with 178 additions and 27 deletions
  1. +54
    -27
      nova/compute/manager.py
  2. +124
    -0
      nova/tests/unit/compute/test_compute_mgr.py

+ 54
- 27
nova/compute/manager.py View File

@@ -7323,6 +7323,50 @@ class ComputeManager(manager.Manager):
action=fields.NotificationAction.LIVE_MIGRATION_POST_DEST,
phase=fields.NotificationPhase.END)

def _remove_remote_volume_connections(self, context, dest, bdms, instance):
"""Rollback remote volume connections on the dest"""
for bdm in bdms:
try:
# remove the connection on the destination host
# NOTE(lyarwood): This actually calls the cinderv2
# os-terminate_connection API if required.
self.compute_rpcapi.remove_volume_connection(
context, instance, bdm.volume_id, dest)
except Exception:
LOG.warning("Ignoring exception while attempting "
"to rollback volume connections for "
"volume %s on host %s.", bdm.volume_id,
dest, instance=instance)

def _rollback_volume_bdms(self, context, bdms, original_bdms, instance):
"""Rollback the connection_info and attachment_id for each bdm"""
original_bdms_by_volid = {bdm.volume_id: bdm for bdm in original_bdms
if bdm.is_volume}
for bdm in bdms:
try:
original_bdm = original_bdms_by_volid[bdm.volume_id]
if bdm.attachment_id and original_bdm.attachment_id:
# NOTE(lyarwood): 3.44 cinder api flow. Delete the
# attachment used by the bdm and reset it to that of
# the original bdm.
self.volume_api.attachment_delete(context,
bdm.attachment_id)
bdm.attachment_id = original_bdm.attachment_id
# NOTE(lyarwood): Reset the connection_info to the original
bdm.connection_info = original_bdm.connection_info
bdm.save()
except cinder_exception.ClientException:
LOG.warning("Ignoring cinderclient exception when "
"attempting to delete attachment %s for volume"
"%s while rolling back volume bdms.",
bdm.attachment_id, bdm.volume_id,
instance=instance)
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception("Exception while attempting to rollback "
"BDM for volume %s.", bdm.volume_id,
instance=instance)

@wrap_exception()
@wrap_instance_fault
def _rollback_live_migration(self, context, instance,
@@ -7371,35 +7415,18 @@ class ComputeManager(manager.Manager):
# NOTE(mriedem): This is a no-op for neutron.
self.network_api.setup_networks_on_host(context, instance, self.host)

source_bdms_by_volid = {bdm.volume_id: bdm for bdm in source_bdms
if bdm.is_volume}

# NOTE(lyarwood): Fetch the current list of BDMs and delete any volume
# attachments used by the destination host before rolling back to the
# original and still valid source host volume attachments.
# NOTE(lyarwood): Fetch the current list of BDMs, disconnect any
# connected volumes from the dest and delete any volume attachments
# used by the destination host before rolling back to the original
# still valid source host volume attachments.
bdms = objects.BlockDeviceMappingList.get_by_instance_uuid(
context, instance.uuid)
for bdm in bdms:
if bdm.is_volume:
# remove the connection on the destination host
# NOTE(lyarwood): This actually calls the cinderv2
# os-terminate_connection API if required.
self.compute_rpcapi.remove_volume_connection(
context, instance, bdm.volume_id, dest)

source_bdm = source_bdms_by_volid[bdm.volume_id]
if bdm.attachment_id and source_bdm.attachment_id:
# NOTE(lyarwood): 3.44 cinder api flow. Delete the
# attachment used by the destination and reset the bdm
# attachment_id to the old attachment of the source host.
self.volume_api.attachment_delete(context,
bdm.attachment_id)
bdm.attachment_id = source_bdm.attachment_id

# NOTE(lyarwood): Rollback the connection_info stored within
# the BDM to that used by the source and not the destination.
bdm.connection_info = source_bdm.connection_info
bdm.save()
# TODO(lyarwood): Turn the following into a lookup method within
# BlockDeviceMappingList.
vol_bdms = [bdm for bdm in bdms if bdm.is_volume]
self._remove_remote_volume_connections(context, dest, vol_bdms,
instance)
self._rollback_volume_bdms(context, vol_bdms, source_bdms, instance)

self._notify_about_instance_usage(context, instance,
"live_migration._rollback.start")


+ 124
- 0
nova/tests/unit/compute/test_compute_mgr.py View File

@@ -8809,6 +8809,130 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase,

_test()

def _generate_volume_bdm_list(self, instance, original=False):
# TODO(lyarwood): There are various methods generating fake bdms within
# this class, we should really look at writing a small number of
# generic reusable methods somewhere to replace all of these.
connection_info = "{'data': {'host': 'dest'}}"
if original:
connection_info = "{'data': {'host': 'original'}}"

vol1_bdm = fake_block_device.fake_bdm_object(
self.context,
{'source_type': 'volume', 'destination_type': 'volume',
'volume_id': uuids.vol1, 'device_name': '/dev/vdb',
'instance_uuid': instance.uuid,
'connection_info': connection_info})
vol1_bdm.save = mock.Mock()
vol2_bdm = fake_block_device.fake_bdm_object(
self.context,
{'source_type': 'volume', 'destination_type': 'volume',
'volume_id': uuids.vol2, 'device_name': '/dev/vdc',
'instance_uuid': instance.uuid,
'connection_info': connection_info})
vol2_bdm.save = mock.Mock()

if original:
vol1_bdm.attachment_id = uuids.vol1_attach_original
vol2_bdm.attachment_id = uuids.vol2_attach_original
else:
vol1_bdm.attachment_id = uuids.vol1_attach
vol2_bdm.attachment_id = uuids.vol2_attach
return objects.BlockDeviceMappingList(objects=[vol1_bdm, vol2_bdm])

@mock.patch('nova.compute.rpcapi.ComputeAPI.remove_volume_connection')
def test_remove_remote_volume_connections(self, mock_remove_vol_conn):
instance = fake_instance.fake_instance_obj(self.context,
uuid=uuids.instance)
bdms = self._generate_volume_bdm_list(instance)

self.compute._remove_remote_volume_connections(self.context, 'fake',
bdms, instance)
mock_remove_vol_conn.assert_has_calls = [
mock.call(self.context, instance, bdm.volume_id, 'fake') for
bdm in bdms]

@mock.patch('nova.compute.rpcapi.ComputeAPI.remove_volume_connection')
def test_remove_remote_volume_connections_exc(self, mock_remove_vol_conn):
instance = fake_instance.fake_instance_obj(self.context,
uuid=uuids.instance)
bdms = self._generate_volume_bdm_list(instance)

# Raise an exception for the second call to remove_volume_connections
mock_remove_vol_conn.side_effect = [None, test.TestingException]

# Assert that errors are ignored
self.compute._remove_remote_volume_connections(self.context,
'fake', bdms, instance)

@mock.patch('nova.volume.cinder.API.attachment_delete')
def test_rollback_volume_bdms(self, mock_delete_attachment):
instance = fake_instance.fake_instance_obj(self.context,
uuid=uuids.instance)
bdms = self._generate_volume_bdm_list(instance)
original_bdms = self._generate_volume_bdm_list(instance,
original=True)

self.compute._rollback_volume_bdms(self.context, bdms,
original_bdms, instance)

# Assert that we delete the current attachments
mock_delete_attachment.assert_has_calls = [
mock.call(self.context, uuids.vol1_attach),
mock.call(self.context, uuids.vol2_attach)]
# Assert that we switch the attachment ids and connection_info for each
# bdm back to their original values
self.assertEqual(uuids.vol1_attach_original,
bdms[0].attachment_id)
self.assertEqual("{'data': {'host': 'original'}}",
bdms[0].connection_info)
self.assertEqual(uuids.vol2_attach_original,
bdms[1].attachment_id)
self.assertEqual("{'data': {'host': 'original'}}",
bdms[1].connection_info)
# Assert that save is called for each bdm
bdms[0].save.assert_called_once()
bdms[1].save.assert_called_once()

@mock.patch('nova.compute.manager.LOG')
@mock.patch('nova.volume.cinder.API.attachment_delete')
def test_rollback_volume_bdms_exc(self, mock_delete_attachment, mock_log):
instance = fake_instance.fake_instance_obj(self.context,
uuid=uuids.instance)
bdms = self._generate_volume_bdm_list(instance)
original_bdms = self._generate_volume_bdm_list(instance,
original=True)

# Assert that we ignore cinderclient exceptions and continue to attempt
# to rollback any remaining bdms.
mock_delete_attachment.side_effect = [
cinder_exception.ClientException(code=9001), None]
self.compute._rollback_volume_bdms(self.context, bdms,
original_bdms, instance)
self.assertEqual(uuids.vol2_attach_original,
bdms[1].attachment_id)
self.assertEqual("{'data': {'host': 'original'}}",
bdms[1].connection_info)
bdms[0].save.assert_not_called()
bdms[1].save.assert_called_once()
mock_log.warning.assert_called_once()
self.assertIn('Ignoring cinderclient exception',
mock_log.warning.call_args[0][0])

# Assert that we raise unknown Exceptions
mock_log.reset_mock()
bdms[0].save.reset_mock()
bdms[1].save.reset_mock()
mock_delete_attachment.side_effect = test.TestingException
self.assertRaises(test.TestingException,
self.compute._rollback_volume_bdms, self.context,
bdms, original_bdms, instance)
bdms[0].save.assert_not_called()
bdms[1].save.assert_not_called()
mock_log.exception.assert_called_once()
self.assertIn('Exception while attempting to rollback',
mock_log.exception.call_args[0][0])

@mock.patch.object(objects.ComputeNode,
'get_first_node_by_host_for_old_compat')
@mock.patch('nova.scheduler.client.report.SchedulerReportClient.'


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