openstack/nova
Code Issues Proposed changes

Remove marker from nova-manage cells_v2 map_instances UI

Browse Source 
For a better user experience let's do the right thing. If no max-count
is passed in that means looping through all instances in batches, and if
max-count is used we store a marker to be used for later calls.

Because the marker is the last instance mapped there's already an entry
for that UUID in the instance_mappings table. In order to satisfy the
unique constraint on that column the marker UUID is modified by
replacing '-' with ' ' so that it can be transformed back when needed.

Change-Id: I921258d59e3054cbe874cab96cc8cc47c9a24845
This commit is contained in:
Andrew Laski 2016-04-05 14:03:00 -04:00
parent 6a39fad56c
commit 4679f185cf
2 changed files with 160 additions and 36 deletions
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106
nova/cmd/manage.py
View File

@ -1157,34 +1157,13 @@ class CellV2Commands(object):
database_connection=dbc)
cell_mapping.create()
@args('--cell_uuid', metavar='<cell_uuid>', required=True,
help='Unmigrated instances will be mapped to the cell with the '
'uuid provided.')
@args('--limit', metavar='<limit>',
help='Maximum number of instances to map')
@args('--marker', metavar='<marker',
help='The last updated instance UUID')
@args('--verbose', metavar='<verbose>',
help='Provide output for the registration')
def map_instances(self, cell_uuid, limit=None,
marker=None, verbose=0):
if limit is not None:
limit = int(limit)
if limit < 0:
print('Must supply a positive value for limit')
return(1)
ctxt = context.get_admin_context(read_deleted='yes')
# Validate the cell exists
cell_mapping = objects.CellMapping.get_by_uuid(ctxt, cell_uuid)
def _get_and_map_instances(self, ctxt, cell_mapping, limit, marker):
filters = {}
instances = objects.InstanceList.get_by_filters(
ctxt, filters, sort_key='created_at', sort_dir='asc',
limit=limit, marker=marker)
if verbose:
fmt = "%s instances retrieved to be mapped to cell %s"
print(fmt % (len(instances), cell_uuid))
ctxt.elevated(read_deleted='yes'), filters,
sort_key='created_at', sort_dir='asc', limit=limit,
marker=marker)
mapped = 0
for instance in instances:
try:
mapping = objects.InstanceMapping(ctxt)
@ -1193,16 +1172,77 @@ class CellV2Commands(object):
mapping.project_id = instance.project_id
mapping.create()
except db_exc.DBDuplicateEntry:
if verbose:
print("%s already mapped to cell" % instance.uuid)
continue
mapped += 1
fmt = "%s instances registered to cell %s"
print(fmt % (mapped, cell_mapping.uuid))
if instances:
instance = instances[-1]
print('Next marker: - %s' % instance.uuid)
if len(instances) == 0 or len(instances) < limit:
# We've hit the end of the instances table
marker = None
else:
marker = instances[-1].uuid
return marker
@args('--cell_uuid', metavar='<cell_uuid>', required=True,
help='Unmigrated instances will be mapped to the cell with the '
'uuid provided.')
@args('--max-count', metavar='<max_count>',
help='Maximum number of instances to map')
def map_instances(self, cell_uuid, max_count=None):
"""Map instances into the provided cell.
This assumes that Nova on this host is still configured to use the nova
database not just the nova-api database. Instances in the nova database
will be queried from oldest to newest and mapped to the provided cell.
A max-count can be set on the number of instance to map in a single
run. Repeated runs of the command will start from where the last run
finished so it is not necessary to increase max-count to finish. An
exit code of 0 indicates that all instances have been mapped.
"""
if max_count is not None:
try:
max_count = int(max_count)
except ValueError:
max_count = -1
map_all = False
if max_count < 1:
print(_('Must supply a positive value for max-count'))
return 127
else:
map_all = True
max_count = 50
ctxt = context.RequestContext()
marker_project_id = 'INSTANCE_MIGRATION_MARKER'
# Validate the cell exists, this will raise if not
cell_mapping = objects.CellMapping.get_by_uuid(ctxt, cell_uuid)
# Check for a marker from a previous run
marker_mapping = objects.InstanceMappingList.get_by_project_id(ctxt,
marker_project_id)
if len(marker_mapping) == 0:
marker = None
else:
# There should be only one here
marker = marker_mapping[0].instance_uuid.replace(' ', '-')
marker_mapping[0].destroy()
next_marker = True
while next_marker is not None:
next_marker = self._get_and_map_instances(ctxt, cell_mapping,
max_count, marker)
marker = next_marker
if not map_all:
break
if next_marker:
# Don't judge me. There's already an InstanceMapping with this UUID
# so the marker needs to be non destructively modified.
next_marker = next_marker.replace('-', ' ')
objects.InstanceMapping(ctxt, instance_uuid=next_marker,
project_id=marker_project_id).create()
return 1
return 0
# TODO(melwitt): Remove this when the oslo.messaging function
# for assembling a transport url from ConfigOpts is available

90
nova/tests/unit/test_nova_manage.py
View File

@ -876,10 +876,94 @@ class CellV2CommandsTestCase(test.TestCase):
instance_uuid=instance_uuids[0],
cell_mapping=cell_mapping).create()
self.commands.map_instances(cell_uuid, verbose=True)
output = sys.stdout.getvalue().strip()
self.commands.map_instances(cell_uuid)
self.assertIn('%s already mapped to cell' % instance_uuids[0], output)
for uuid in instance_uuids:
inst_mapping = objects.InstanceMapping.get_by_instance_uuid(ctxt,
uuid)
self.assertEqual(ctxt.project_id, inst_mapping.project_id)
mappings = objects.InstanceMappingList.get_by_project_id(ctxt,
ctxt.project_id)
self.assertEqual(3, len(mappings))
def test_map_instances_two_batches(self):
ctxt = context.RequestContext('fake-user', 'fake_project')
cell_uuid = uuidutils.generate_uuid()
cell_mapping = objects.CellMapping(
ctxt, uuid=cell_uuid, name='fake',
transport_url='fake://', database_connection='fake://')
cell_mapping.create()
instance_uuids = []
# Batch size is 50 in map_instances
for i in range(60):
uuid = uuidutils.generate_uuid()
instance_uuids.append(uuid)
objects.Instance(ctxt, project_id=ctxt.project_id,
uuid=uuid).create()
ret = self.commands.map_instances(cell_uuid)
self.assertEqual(0, ret)
for uuid in instance_uuids:
inst_mapping = objects.InstanceMapping.get_by_instance_uuid(ctxt,
uuid)
self.assertEqual(ctxt.project_id, inst_mapping.project_id)
def test_map_instances_max_count(self):
ctxt = context.RequestContext('fake-user', 'fake_project')
cell_uuid = uuidutils.generate_uuid()
cell_mapping = objects.CellMapping(
ctxt, uuid=cell_uuid, name='fake',
transport_url='fake://', database_connection='fake://')
cell_mapping.create()
instance_uuids = []
for i in range(6):
uuid = uuidutils.generate_uuid()
instance_uuids.append(uuid)
objects.Instance(ctxt, project_id=ctxt.project_id,
uuid=uuid).create()
ret = self.commands.map_instances(cell_uuid, max_count=3)
self.assertEqual(1, ret)
for uuid in instance_uuids[:3]:
# First three are mapped
inst_mapping = objects.InstanceMapping.get_by_instance_uuid(ctxt,
uuid)
self.assertEqual(ctxt.project_id, inst_mapping.project_id)
for uuid in instance_uuids[3:]:
# Last three are not
self.assertRaises(exception.InstanceMappingNotFound,
objects.InstanceMapping.get_by_instance_uuid, ctxt,
uuid)
def test_map_instances_marker_deleted(self):
ctxt = context.RequestContext('fake-user', 'fake_project')
cell_uuid = uuidutils.generate_uuid()
cell_mapping = objects.CellMapping(
ctxt, uuid=cell_uuid, name='fake',
transport_url='fake://', database_connection='fake://')
cell_mapping.create()
instance_uuids = []
for i in range(6):
uuid = uuidutils.generate_uuid()
instance_uuids.append(uuid)
objects.Instance(ctxt, project_id=ctxt.project_id,
uuid=uuid).create()
ret = self.commands.map_instances(cell_uuid, max_count=3)
self.assertEqual(1, ret)
# Instances are mapped in the order created so we know the marker is
# based off the third instance.
marker = instance_uuids[2].replace('-', ' ')
marker_mapping = objects.InstanceMapping.get_by_instance_uuid(ctxt,
marker)
marker_mapping.destroy()
ret = self.commands.map_instances(cell_uuid)
self.assertEqual(0, ret)
for uuid in instance_uuids:
inst_mapping = objects.InstanceMapping.get_by_instance_uuid(ctxt,