vmware-nsx/neutron/plugins/bigswitch/db/consistency_db.py
Kevin Benton 095aa20e3e BigSwitch: Auto re-sync on backend inconsistencies
If the controller supports it, pass a hash to the
controller indicating the expected state that a
REST transaction is updating. If the state is
inconsistent, the controller will return an error
indicating a conflict and the plugin/driver will
trigger a full synchronization.

For controllers that don't support the consistency
hash, trigger a full background synchronization
if the plugin tries to create a port and receives
a 404 error due to the parent network not existing.

Implements: blueprint bsn-auto-resync
Change-Id: I07c92b011453f6bf81b8ee12661170817287cdd7
2014-03-05 15:08:39 -05:00

57 lines
1.8 KiB
Python

# Copyright 2014, Big Switch Networks
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import sqlalchemy as sa
from neutron.db import api as db
from neutron.db import model_base
from neutron.openstack.common import log as logging
LOG = logging.getLogger(__name__)
'''
A simple table to store the latest consistency hash
received from a server in case neutron gets restarted.
'''
class ConsistencyHash(model_base.BASEV2):
'''
For now we only support one global state so the
hash_id will always be '1'
'''
__tablename__ = 'consistencyhashes'
hash_id = sa.Column(sa.String(255),
primary_key=True)
hash = sa.Column(sa.String(255), nullable=False)
def get_consistency_hash(hash_id='1'):
session = db.get_session()
with session.begin(subtransactions=True):
query = session.query(ConsistencyHash)
res = query.filter_by(hash_id=hash_id).first()
if not res:
return False
return res.hash
def put_consistency_hash(hash, hash_id='1'):
session = db.get_session()
with session.begin(subtransactions=True):
conhash = ConsistencyHash(hash_id=hash_id, hash=hash)
session.merge(conhash)
LOG.debug(_("Consistency hash for group %(hash_id)s updated "
"to %(hash)s"), {'hash_id': hash_id, 'hash': hash})