Merge "Revert "Change transaction isolation so retry logic could work properly""

neutron/db/sqlalchemyutils.py

@@ -13,8 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import contextlib
-
 from six import moves
 import sqlalchemy
 from sqlalchemy.orm import properties
@@ -107,27 +105,3 @@ def paginate_query(query, model, limit, sorts, marker_obj=None):
         query = query.limit(limit)
 
     return query
-
-
-default_tx_isolation_level = None
-
-
-def get_default_tx_level(engine):
-    global default_tx_isolation_level
-    if not default_tx_isolation_level:
-        default_tx_isolation_level = engine.dialect.get_isolation_level(
-            engine.raw_connection())
-    return default_tx_isolation_level
-
-
-@contextlib.contextmanager
-def set_mysql_tx_isolation_level(session, level):
-    engine = session.connection().engine
-    if (engine.name == "mysql" and level != get_default_tx_level(engine)):
-        session.connection().execution_options(
-            isolation_level=level)
-    yield
-    engine = session.connection().engine
-    if engine.name == "mysql":
-        session.connection().execution_options(
-            isolation_level=get_default_tx_level(engine))

neutron/plugins/ml2/plugin.py

@@ -48,7 +48,6 @@ from neutron.db import extradhcpopt_db
 from neutron.db import models_v2
 from neutron.db import quota_db  # noqa
 from neutron.db import securitygroups_rpc_base as sg_db_rpc
-from neutron.db import sqlalchemyutils as sqla
 from neutron.extensions import allowedaddresspairs as addr_pair
 from neutron.extensions import extra_dhcp_opt as edo_ext
 from neutron.extensions import l3agentscheduler
@@ -539,10 +538,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         net_data = network[attributes.NETWORK]
         tenant_id = self._get_tenant_id_for_create(context, net_data)
         session = context.session
-        with contextlib.nested(
-            session.begin(subtransactions=True),
-            sqla.set_mysql_tx_isolation_level(session, "READ COMMITTED")
-        ):
+        with session.begin(subtransactions=True):
             self._ensure_default_security_group(context, tenant_id)
             result = super(Ml2Plugin, self).create_network(context, network)
             self.extension_manager.process_create_network(session, net_data,

neutron/tests/functional/db/test_sqla_utils.py

@@ -1,57 +0,0 @@
-# Copyright (c) 2014 OpenStack Foundation.
-# 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 contextlib
-
-from oslo.config import cfg
-from oslo.db.sqlalchemy import test_base
-
-from neutron import context
-from neutron.db import sqlalchemyutils
-from neutron.tests import base
-
-
-class TestSettingTXIsolationLevel(base.BaseTestCase,
-                                  test_base.MySQLOpportunisticTestCase):
-    """Check that transaction isolation level indeed changes."""
-
-    def setUp(self):
-        super(TestSettingTXIsolationLevel, self).setUp()
-        cfg.CONF.set_override('connection',
-                              self.engine.url,
-                              group='database')
-
-    def _get_session_tx_isolation(self, session):
-        sql = "SELECT @@tx_isolation;"
-        res = session.connection().execute(sql)
-        res = [r for r in res]
-        res = [r for r in res[0]]
-        return res[0]
-
-    def test_set_tx_iso_level_changes_back_and_forth_mysql(self):
-        ctx = context.get_admin_context()
-        default_level = sqlalchemyutils.get_default_tx_level(self.engine)
-        other_level = ("READ COMMITTED" if default_level == "REPEATABLE READ"
-                       else "REPEATABLE READ")
-        with contextlib.nested(
-            ctx.session.begin(subtransactions=True),
-            sqlalchemyutils.set_mysql_tx_isolation_level(
-                ctx.session, other_level)
-        ):
-            res = self._get_session_tx_isolation(ctx.session)
-            self.assertEqual(other_level.replace(' ', '-'), res)
-        #check that context manager changes tx isolation level back
-        res = self._get_session_tx_isolation(ctx.session)
-        self.assertEqual(default_level.replace(' ', '-'), res)