on-delete cascade rule for resource_data

During deleting of resource, the resource_data is also loaded in memory
and then deleted. This is not performant. The passive_delete option in
relationship deletes the relation without loading the children. This
patch configures the resource to have a passive-delete relationship with
resource_data and configures ondelete CASCADE so that the DB takes care
of deleting the resource_data when a resource is deleted.

This patch proposes the following changes:
- When deleting a resource do not load resource_data.
- When a resource is deleted, DB takes care of deleting resource_data.

The resource data remains intact when the FK constraints are deleted and
added to reflect on-delete cascade.

Change-Id: I4162e6f9ad9582fcb304887e5d3718de220231ec
Closes-Bug: #1573585
This commit is contained in:
Rakesh H S 2016-04-21 18:47:12 +05:30 committed by Anant Patil
parent 3b7731ddce
commit ed8a086556
3 changed files with 64 additions and 5 deletions

View File

@ -0,0 +1,44 @@
#
# 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.
# This is a placeholder for Liberty backports.
# Do not use this number for new Mitaka work. New Mitaka work starts after
# all the placeholders.
import sqlalchemy
from migrate import ForeignKeyConstraint
def upgrade(migrate_engine):
meta = sqlalchemy.MetaData()
meta.bind = migrate_engine
resource_data = sqlalchemy.Table('resource_data', meta, autoload=True)
resource = sqlalchemy.Table('resource', meta, autoload=True)
for fk in resource_data.foreign_keys:
if fk.column == resource.c.id:
# delete the existing fk
# and create with ondelete cascade and a proper name
existing_fkey = ForeignKeyConstraint(
columns=[resource_data.c.resource_id],
refcolumns=[resource.c.id], name=fk.name)
existing_fkey.drop()
fkey = ForeignKeyConstraint(
columns=[resource_data.c.resource_id],
refcolumns=[resource.c.id],
name="fk_resource_id", ondelete='CASCADE')
fkey.create()
break

View File

@ -276,10 +276,11 @@ class ResourceData(BASE, HeatBase):
value = sqlalchemy.Column('value', sqlalchemy.Text)
redact = sqlalchemy.Column('redact', sqlalchemy.Boolean)
decrypt_method = sqlalchemy.Column(sqlalchemy.String(64))
resource_id = sqlalchemy.Column('resource_id',
sqlalchemy.Integer,
sqlalchemy.ForeignKey('resource.id'),
nullable=False)
resource_id = sqlalchemy.Column(
'resource_id', sqlalchemy.Integer,
sqlalchemy.ForeignKey(column='resource.id', name='fk_resource_id',
ondelete='CASCADE'),
nullable=False)
class Resource(BASE, HeatBase, StateAware):
@ -303,7 +304,8 @@ class Resource(BASE, HeatBase, StateAware):
stack = relationship(Stack, backref=backref('resources'))
root_stack_id = sqlalchemy.Column(sqlalchemy.String(36), index=True)
data = relationship(ResourceData,
cascade="all,delete",
cascade="all",
passive_deletes=True,
backref=backref('resource'))
# Override timestamp column to store the correct value: it should be the

View File

@ -747,6 +747,19 @@ class HeatMigrationsCheckers(test_migrations.WalkVersionsMixin,
self.assertIndexMembers(engine, 'stack', 'ix_stack_owner_id',
['owner_id'])
def _check_073(self, engine, data):
# check if column still exists and is not nullable.
self.assertColumnIsNotNullable(engine, 'resource_data', 'resource_id')
# Ensure that only one foreign key exists and is created as expected.
inspector = sqlalchemy.engine.reflection.Inspector.from_engine(engine)
resource_data_fkeys = inspector.get_foreign_keys('resource_data')
self.assertEqual(1, len(resource_data_fkeys))
fk = resource_data_fkeys[0]
self.assertEqual('fk_resource_id', fk['name'])
self.assertEqual(['resource_id'], fk['constrained_columns'])
self.assertEqual('resource', fk['referred_table'])
self.assertEqual(['id'], fk['referred_columns'])
class TestHeatMigrationsMySQL(HeatMigrationsCheckers,
test_base.MySQLOpportunisticTestCase):