openstack
/
nova
Code Issues Proposed changes

enginefacade: 'migration' 

Use enginefacade in 'migration' section.

New 'select_db_reader_mode' decorator was introduced.
It is needed to select and set synchronous or asynchronous
reader mode to object's functions. The transaction mode
will be passed to sqlalchemy layer and correctly supported
there by enginefacade allow_async property. New decorator
uses 'use_slave' parameter which is now removed from db and
sqlalchemy layers.

Implements: blueprint new-oslodb-enginefacade

Co-Authored-By: Sergey Nikitin <snikitin@mirantis.com>

Change-Id: I339a50e53652e5690ece33ee711fbea2cca61f65
This commit is contained in:
Pavel Kholkin 2015-11-30 18:04:53 +03:00
parent 997bec1bb9
commit 6eb1c0e1bc
5 changed files with 120 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
nova/db/api.py
View File

@ -89,6 +89,18 @@ def not_equal(*values):
###################
def select_db_reader_mode(f):
"""Decorator to select synchronous or asynchronous reader mode.
The kwarg argument 'use_slave' defines reader mode. Asynchronous reader
will be used if 'use_slave' is True and synchronous reader otherwise.
"""
return IMPL.select_db_reader_mode(f)
###################
def service_destroy(context, service_id):
"""Destroy the service or raise if it does not exist."""
return IMPL.service_destroy(context, service_id)
@ -470,12 +482,12 @@ def migration_get_by_instance_and_status(context, instance_uuid, status):
def migration_get_unconfirmed_by_dest_compute(context, confirm_window,
dest_compute, use_slave=False):
dest_compute):
"""Finds all unconfirmed migrations within the confirmation window for
a specific destination compute host.
"""
return IMPL.migration_get_unconfirmed_by_dest_compute(context,
confirm_window, dest_compute, use_slave=use_slave)
confirm_window, dest_compute)
def migration_get_in_progress_by_host_and_node(context, host, node):

59
nova/db/sqlalchemy/api.py
View File

@ -21,6 +21,7 @@ import collections
import copy
import datetime
import functools
import inspect
import sys
import uuid
@ -64,6 +65,7 @@ from nova.db.sqlalchemy import models
from nova import exception
from nova.i18n import _, _LI, _LE, _LW
from nova import quota
from nova import safe_utils
db_opts = [
cfg.StrOpt('osapi_compute_unique_server_name_scope',
@ -232,6 +234,34 @@ def require_aggregate_exists(f):
return wrapper
def select_db_reader_mode(f):
"""Decorator to select synchronous or asynchronous reader mode.
The kwarg argument 'use_slave' defines reader mode. Asynchronous reader
will be used if 'use_slave' is True and synchronous reader otherwise.
If 'use_slave' is not specified default value 'False' will be used.
Wrapped function must have a context in the arguments.
"""
@functools.wraps(f)
def wrapper(*args, **kwargs):
wrapped_func = safe_utils.get_wrapped_function(f)
keyed_args = inspect.getcallargs(wrapped_func, *args, **kwargs)
context = keyed_args['context']
use_slave = keyed_args.get('use_slave', False)
if use_slave:
reader_mode = main_context_manager.async
else:
reader_mode = main_context_manager.reader
with reader_mode.using(context):
return f(*args, **kwargs)
return wrapper
def model_query(context, model,
args=None,
session=None,
@ -4441,25 +4471,25 @@ def project_get_networks(context, project_id, associate=True):
###################
@main_context_manager.writer
def migration_create(context, values):
migration = models.Migration()
migration.update(values)
migration.save()
migration.save(context.session)
return migration
@main_context_manager.writer
def migration_update(context, id, values):
session = get_session()
with session.begin():
migration = _migration_get(context, id, session=session)
migration.update(values)
migration = migration_get(context, id)
migration.update(values)
return migration
def _migration_get(context, id, session=None):
result = model_query(context, models.Migration, session=session,
read_deleted="yes").\
@main_context_manager.reader
def migration_get(context, id):
result = model_query(context, models.Migration, read_deleted="yes").\
filter_by(id=id).\
first()
@ -4469,10 +4499,7 @@ def _migration_get(context, id, session=None):
return result
def migration_get(context, id):
return _migration_get(context, id)
@main_context_manager.reader
def migration_get_by_instance_and_status(context, instance_uuid, status):
result = model_query(context, models.Migration, read_deleted="yes").\
filter_by(instance_uuid=instance_uuid).\
@ -4486,19 +4513,20 @@ def migration_get_by_instance_and_status(context, instance_uuid, status):
return result
@main_context_manager.reader.allow_async
def migration_get_unconfirmed_by_dest_compute(context, confirm_window,
dest_compute, use_slave=False):
dest_compute):
confirm_window = (timeutils.utcnow() -
datetime.timedelta(seconds=confirm_window))
return model_query(context, models.Migration, read_deleted="yes",
use_slave=use_slave).\
return model_query(context, models.Migration, read_deleted="yes").\
filter(models.Migration.updated_at <= confirm_window).\
filter_by(status="finished").\
filter_by(dest_compute=dest_compute).\
all()
@main_context_manager.reader
def migration_get_in_progress_by_host_and_node(context, host, node):
return model_query(context, models.Migration).\
@ -4512,6 +4540,7 @@ def migration_get_in_progress_by_host_and_node(context, host, node):
all()
@main_context_manager.reader
def migration_get_all_by_filters(context, filters):
query = model_query(context, models.Migration)
if "status" in filters:

9
nova/objects/migration.py
View File

@ -134,10 +134,17 @@ class MigrationList(base.ObjectListBase, base.NovaObject):
'objects': fields.ListOfObjectsField('Migration'),
}
@staticmethod
@db.select_db_reader_mode
def _db_migration_get_unconfirmed_by_dest_compute(
context, confirm_window, dest_compute, use_slave=False):
return db.migration_get_unconfirmed_by_dest_compute(
context, confirm_window, dest_compute)
@base.remotable_classmethod
def get_unconfirmed_by_dest_compute(cls, context, confirm_window,
dest_compute, use_slave=False):
db_migrations = db.migration_get_unconfirmed_by_dest_compute(
db_migrations = cls._db_migration_get_unconfirmed_by_dest_compute(
context, confirm_window, dest_compute, use_slave=use_slave)
return base.obj_make_list(context, cls(context), objects.Migration,
db_migrations)

53
nova/tests/unit/db/test_db_api.py
View File

@ -28,6 +28,7 @@ import netaddr
from oslo_config import cfg
from oslo_db import api as oslo_db_api
from oslo_db import exception as db_exc
from oslo_db.sqlalchemy import enginefacade
from oslo_db.sqlalchemy import test_base
from oslo_db.sqlalchemy import update_match
from oslo_db.sqlalchemy import utils as sqlalchemyutils
@ -180,6 +181,58 @@ class DecoratorTestCase(test.TestCase):
self._test_decorator_wraps_helper(
oslo_db_api.wrap_db_retry(max_retries=5, retry_on_deadlock=True))
@mock.patch.object(enginefacade._TransactionContextManager, 'using')
@mock.patch.object(enginefacade._TransactionContextManager, '_clone')
def test_select_db_reader_mode_select_sync(self, mock_clone, mock_using):
@db.select_db_reader_mode
def func(self, context, value, use_slave=False):
pass
mock_clone.return_value = enginefacade._TransactionContextManager(
mode=enginefacade._READER)
ctxt = context.get_admin_context()
value = 'some_value'
func(self, ctxt, value)
mock_clone.assert_called_once_with(mode=enginefacade._READER)
mock_using.assert_called_once_with(ctxt)
@mock.patch.object(enginefacade._TransactionContextManager, 'using')
@mock.patch.object(enginefacade._TransactionContextManager, '_clone')
def test_select_db_reader_mode_select_async(self, mock_clone, mock_using):
@db.select_db_reader_mode
def func(self, context, value, use_slave=False):
pass
mock_clone.return_value = enginefacade._TransactionContextManager(
mode=enginefacade._ASYNC_READER)
ctxt = context.get_admin_context()
value = 'some_value'
func(self, ctxt, value, use_slave=True)
mock_clone.assert_called_once_with(mode=enginefacade._ASYNC_READER)
mock_using.assert_called_once_with(ctxt)
@mock.patch.object(enginefacade._TransactionContextManager, 'using')
@mock.patch.object(enginefacade._TransactionContextManager, '_clone')
def test_select_db_reader_mode_no_use_slave_select_sync(self, mock_clone,
mock_using):
@db.select_db_reader_mode
def func(self, context, value):
pass
mock_clone.return_value = enginefacade._TransactionContextManager(
mode=enginefacade._READER)
ctxt = context.get_admin_context()
value = 'some_value'
func(self, ctxt, value)
mock_clone.assert_called_once_with(mode=enginefacade._READER)
mock_using.assert_called_once_with(ctxt)
def _get_fake_aggr_values():
return {'name': 'fake_aggregate'}

3
nova/tests/unit/objects/test_migration.py
View File

@ -150,8 +150,7 @@ class _TestMigrationObject(object):
self.mox.StubOutWithMock(
db, 'migration_get_unconfirmed_by_dest_compute')
db.migration_get_unconfirmed_by_dest_compute(
ctxt, 'window', 'foo',
use_slave=False).AndReturn(db_migrations)
ctxt, 'window', 'foo').AndReturn(db_migrations)
self.mox.ReplayAll()
migrations = (
migration.MigrationList.get_unconfirmed_by_dest_compute(