openstack/neutron
Code Issues Proposed changes

Merge "[OVN] Create a deterministic hash ring node UUID generator"

Browse Source
This commit is contained in:
Zuul
2025-02-14 17:30:43 +00:00
committed by Gerrit Code Review
parent 8985ba6117 9710673ff5
commit a3f3397706
7 changed files with 102 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
doc/source/eventlet_deprecation/index.rst
View File

@@ -105,6 +105,25 @@ The Neutron API consists of the following executables:
mechanism driver.
ML2/OVN
~~~~~~~
The mechanism driver ML2/OVN requires a synchronization method between all
nodes (controllers) and workers. The OVN database events will be received by
all workers in all nodes; however, only one worker should process this event.
The ``HashRingManager``, locally instantiated in each worker, is in charge of
hashing the event received and decide what worker will process the event.
The ``HashRingManager`` uses the information stored in the Neutron database to
determine how many workers are alive at this time. Each worker will register
itself in the Neutron database, creating a register in the table
``ovn_hash_ring``. The UUID of each register is created using a deterministic
method that depends on (1) the hash ring group (always "mechanism_driver" for
the API workers), (2) the host name and (3) the worker ID. If the worker is
restarted, this method will provide the same register UUID and the previous
register (if present in the database) will be overwritten.
.. note::
Right now, only the API server is running without eventlet.

12
neutron/common/wsgi_utils.py
View File

@@ -13,6 +13,8 @@
# License for the specific language governing permissions and limitations
# under the License.
import typing
from oslo_utils import timeutils
from neutron.common import utils
@@ -44,3 +46,13 @@ def get_start_time(default=None, current_time=False):
return int(start_time.decode(encoding='utf-8'))
except ImportError:
return default
def get_api_worker_id() -> typing.Union[int, None]:
"""Return the worker ID number provided by uWSGI"""
try:
# pylint: disable=import-outside-toplevel
import uwsgi
return uwsgi.worker_id()
except ImportError:
return None

17
neutron/db/ovn_hash_ring_db.py
View File

@@ -14,26 +14,33 @@
# under the License.
import datetime
import uuid
from neutron_lib.db import api as db_api
from oslo_config import cfg
from oslo_log import log
from oslo_utils import timeutils
from oslo_utils import uuidutils
from neutron.db.models import ovn as ovn_models
CONF = cfg.CONF
LOG = log.getLogger(__name__)
OVN_HASHRING_UUID_NAMESPACE = uuid.UUID('551ea055-1982-4295-8bc7-207a0d3c9231')
def get_node_uuid(
group_name: str,
host: str,
worker_id: int) -> str:
node_str = '%s%s%s' % (group_name, host, str(worker_id))
return uuid.uuid5(OVN_HASHRING_UUID_NAMESPACE, node_str).hex
# NOTE(ralonsoh): this was migrated from networking-ovn to neutron and should
# be refactored to be integrated in a OVO.
@db_api.retry_if_session_inactive()
def add_node(context, group_name, node_uuid=None, created_at=None):
if node_uuid is None:
node_uuid = uuidutils.generate_uuid()
def add_node(context, group_name, node_uuid, created_at=None):
with db_api.CONTEXT_WRITER.using(context):
kwargs = {'node_uuid': node_uuid,
'hostname': CONF.host,

30
neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
View File

@@ -43,6 +43,7 @@ from oslo_db import exception as os_db_exc
from oslo_log import log
from oslo_service import service as oslo_service
from oslo_utils import timeutils
from oslo_utils import uuidutils
from ovsdbapp.backend.ovs_idl import idlutils
from neutron._i18n import _
@@ -124,7 +125,7 @@ class OVNMechanismDriver(api.MechanismDriver):
self._maintenance_thread = None
self._hash_ring_thread = None
self._hash_ring_probe_event = multiprocessing.Event()
self.node_uuid = None
self._node_uuid = None
self.hash_ring_group = ovn_const.HASH_RING_ML2_GROUP
self.sg_enabled = ovn_acl.is_sg_enabled()
ovn_conf.register_opts()
@@ -203,6 +204,28 @@ class OVNMechanismDriver(api.MechanismDriver):
return self._start_time
@property
def node_uuid(self):
if self._node_uuid:
return self._node_uuid
worker_id = wsgi_utils.get_api_worker_id()
if worker_id is None:
# NOTE(ralonsoh): the hash ring node UUID should be based on the
# Neutron API worker ID. Right now only uWSGI mode is supported.
# The worker ID is provided via ``uwsgi`` library. If other loader
# is used, a random node UUID will be provided.
LOG.warning('uWSGI is the only supported loader for the Neutron '
'API; it provides, via ``uwsgi`` library, the worker '
'ID. If other loader is used, a random hash ring node '
'UUID will be provided')
self._node_uuid = uuidutils.generate_uuid()
else:
self._node_uuid = ovn_hash_ring_db.get_node_uuid(
self.hash_ring_group, cfg.CONF.host, worker_id)
return self._node_uuid
def get_supported_vif_types(self):
vif_types = set()
for ch in self.sb_ovn.chassis_list().execute(check_error=True):
@@ -372,8 +395,9 @@ class OVNMechanismDriver(api.MechanismDriver):
created_at = n_utils.ts_to_datetime(self.start_time)
ovn_hash_ring_db.remove_nodes_from_host(
context, self.hash_ring_group, created_at=created_at)
self.node_uuid = ovn_hash_ring_db.add_node(
context, self.hash_ring_group, created_at=created_at)
ovn_hash_ring_db.add_node(
context, self.hash_ring_group, self.node_uuid,
created_at=created_at)
newer_nodes = ovn_hash_ring_db.get_nodes(
context, self.hash_ring_group, created_at=created_at)
LOG.debug('Hash Ring setup, this worker has detected %s OVN hash '

13
neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
View File

@@ -72,10 +72,14 @@ class TestOVNMechanismDriver(base.TestOVNFunctionalBase):
# Create several OVN hash registers left by a previous execution.
created_at = timeutils.utcnow() - datetime.timedelta(1)
node_uuids = [uuidutils.generate_uuid(),
uuidutils.generate_uuid(),
uuidutils.generate_uuid()]
with db_api.CONTEXT_WRITER.using(self.context):
for _ in range(3):
self.node_uuid = ovn_hash_ring_db.add_node(
self.context, ring_group, created_at=created_at)
for idx in range(3):
ovn_hash_ring_db.add_node(
self.context, ring_group,
node_uuids[idx], created_at=created_at)
# Check the existing OVN hash ring registers.
ovn_hrs = ovn_hash_ring_db.get_nodes(self.context, ring_group)
@@ -83,7 +87,8 @@ class TestOVNMechanismDriver(base.TestOVNFunctionalBase):
start_time = timeutils.utcnow()
self.mech_driver._start_time = int(start_time.timestamp())
for _ in range(3):
for idx in range(3):
self.mech_driver._node_uuid = node_uuids[idx]
self.mech_driver._init_hash_ring(self.context)
ovn_hrs = ovn_hash_ring_db.get_nodes(self.context, ring_group)

10
neutron/tests/unit/db/test_ovn_hash_ring_db.py
View File

@@ -63,7 +63,9 @@ class TestHashRing(testlib_api.SqlTestCaseLight):
group_name=HASH_RING_TEST_GROUP):
nodes = []
for i in range(count):
node_uuid = ovn_hash_ring_db.add_node(self.admin_ctx, group_name)
node_uuid = uuidutils.generate_uuid()
ovn_hash_ring_db.add_node(self.admin_ctx, group_name,
node_uuid)
self.assertIsNotNone(self._get_node_row(node_uuid))
nodes.append(node_uuid)
return nodes
@@ -311,3 +313,9 @@ class TestHashRing(testlib_api.SqlTestCaseLight):
# Assert we only have 3 node entries after the clean up
self.assertEqual(3, ovn_hash_ring_db.count_nodes_from_host(
self.admin_ctx, HASH_RING_TEST_GROUP))
def test_get_node_uuid(self):
# Test get_node_uuid is idempotent
res1 = ovn_hash_ring_db.get_node_uuid('group1', 'host1', 1)
res2 = ovn_hash_ring_db.get_node_uuid('group1', 'host1', 1)
self.assertEqual(res1, res2)

14
neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
View File

@@ -55,9 +55,11 @@ from neutron.common.ovn import constants as ovn_const
from neutron.common.ovn import exceptions as ovn_exceptions
from neutron.common.ovn import hash_ring_manager
from neutron.common.ovn import utils as ovn_utils
from neutron.common import wsgi_utils
from neutron.conf.agent import ovs_conf
from neutron.conf.plugins.ml2.drivers.ovn import ovn_conf
from neutron.db import db_base_plugin_v2
from neutron.db import ovn_hash_ring_db
from neutron.db import ovn_revision_numbers_db
from neutron.db import provisioning_blocks
from neutron.db import securitygroups_db
@@ -3171,6 +3173,18 @@ class TestOVNMechanismDriver(TestOVNMechanismDriverBase):
tag=new_vlan_tag, if_exists=True)
self.nb_ovn.set_lswitch_port.assert_has_calls([expected_call])
@mock.patch.object(wsgi_utils, 'get_api_worker_id', return_value=1)
def test_node_uuid_worker_id(self, *args):
cfg.CONF.set_override('host', 'host1')
node_uuid = ovn_hash_ring_db.get_node_uuid(
self.mech_driver.hash_ring_group, 'host1', 1)
self.assertEqual(node_uuid, self.mech_driver.node_uuid)
@mock.patch.object(wsgi_utils, 'get_api_worker_id', return_value=None)
@mock.patch.object(uuidutils, 'generate_uuid', return_value=123456789)
def test_node_uuid_no_worker_id(self, *args):
self.assertEqual(123456789, self.mech_driver.node_uuid)
class OVNMechanismDriverTestCase(MechDriverSetupBase,
test_plugin.Ml2PluginV2TestCase):