New agent attribute: resources_synced

Agents supporting the guaranteed minimum bandwidth feature need to share
their resource view with neutron-server and in turn with Placement too.
The resource information is synchronized to neutron-server via the
periodic agent heartbeat therefore transient synchronization errors are
fixed by the next heartbeat. But synchronization to Placement is not
done periodically, but on a (mostly) on demand basis. Therefore to fix
transient errors of the synchronization to Placement we must remember
the success/failure of the last synchronization attempt.

This change implements the extension 'agent-resources-synced' and
therefore extends the agent db model and object with a new attribute:
'resources_synced'. This attribute in only meant to be updated
internally. But it can be read via the API for debugging purposes.

APIImpact: The agent resource has a new attribute: resources_synced.

Change-Id: I757d659cea63c8172ca3618d1f581d10236f5e71
Depends-On: https://review.openstack.org/626210
Partial-Bug: #1578989
See-Also: https://review.openstack.org/502306 (nova spec)
See-Also: https://review.openstack.org/508149 (neutron spec)

neutron/db/agents_db.py

@@ -261,6 +261,7 @@ class AgentDbMixin(ext_agent.AgentPluginBase, AgentAvailabilityZoneMixin):
         res['resource_versions'] = self._get_dict(agent, 'resource_versions',
                                                   ignore_missing=True)
         res['availability_zone'] = agent['availability_zone']
+        res['resources_synced'] = agent['resources_synced']
         return db_utils.resource_fields(res, fields)
 
     @db_api.retry_if_session_inactive()

neutron/db/migration/alembic_migrations/versions/EXPAND_HEAD

@@ -1 +1 @@
-195176fb410d
+fb0167bd9639

neutron/db/migration/alembic_migrations/versions/stein/expand/fb0167bd9639_agent_resources_synced.py

@@ -0,0 +1,36 @@
+# Copyright 2019 OpenStack Foundation
+#
+#    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.
+#
+
+from alembic import op
+import sqlalchemy as sa
+
+
+"""agent_resources_synced
+
+Revision ID: fb0167bd9639
+Revises: 195176fb410d
+Create Date: 2019-01-04 12:34:44.563725
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'fb0167bd9639'
+down_revision = '195176fb410d'
+
+
+def upgrade():
+    op.add_column(
+        'agents',
+        sa.Column('resources_synced', sa.Boolean(), server_default=None))

neutron/db/models/agent.py

@@ -53,6 +53,9 @@ class Agent(model_base.BASEV2, model_base.HasId):
     resource_versions = sa.Column(sa.String(8191))
     # load - number of resources hosted by the agent
     load = sa.Column(sa.Integer, server_default='0', nullable=False)
+    # resources_synced: nullable boolean, success of last sync to Placement
+    resources_synced = sa.Column(
+        sa.Boolean, default=None, server_default=None, nullable=True)
 
     @property
     def is_active(self):

neutron/extensions/agent_resources_synced.py

@@ -0,0 +1,20 @@
+# Copyright (c) 2019 Ericsson
+#
+# 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.
+
+from neutron_lib.api.definitions import agent_resources_synced as apidef
+from neutron_lib.api import extensions
+
+
+class Agent_resources_synced(extensions.APIExtensionDescriptor):
+    api_definition = apidef

neutron/objects/agent.py

@@ -14,6 +14,7 @@
 
 from neutron_lib import constants as const
 from neutron_lib.objects import utils as obj_utils
+from oslo_utils import versionutils
 from oslo_versionedobjects import fields as obj_fields
 from sqlalchemy import func
 
@@ -29,7 +30,8 @@ from neutron.objects import common_types
 @base.NeutronObjectRegistry.register
 class Agent(base.NeutronDbObject):
     # Version 1.0: Initial version
-    VERSION = '1.0'
+    # Version 1.1: Added resources_synced
+    VERSION = '1.1'
 
     db_model = agent_model.Agent
 
@@ -48,6 +50,7 @@ class Agent(base.NeutronDbObject):
         'configurations': common_types.DictOfMiscValuesField(),
         'resource_versions': common_types.DictOfMiscValuesField(nullable=True),
         'load': obj_fields.IntegerField(default=0),
+        'resources_synced': obj_fields.BooleanField(nullable=True),
     }
 
     @classmethod
@@ -80,6 +83,12 @@ class Agent(base.NeutronDbObject):
                 cls.load_json_from_str(fields['resource_versions']))
         return fields
 
+    def obj_make_compatible(self, primitive, target_version):
+        super(Agent, self).obj_make_compatible(primitive, target_version)
+        _target_version = versionutils.convert_version_to_tuple(target_version)
+        if _target_version < (1, 1):
+            primitive.pop('resources_synced', None)
+
     @property
     def is_active(self):
         return not utils.is_agent_down(self.heartbeat_timestamp)

neutron/plugins/ml2/plugin.py

@@ -18,6 +18,7 @@ from neutron_lib.agent import constants as agent_consts
 from neutron_lib.agent import topics
 from neutron_lib.api.definitions import address_scope
 from neutron_lib.api.definitions import agent as agent_apidef
+from neutron_lib.api.definitions import agent_resources_synced
 from neutron_lib.api.definitions import allowedaddresspairs as addr_apidef
 from neutron_lib.api.definitions import availability_zone as az_def
 from neutron_lib.api.definitions import availability_zone_filter
@@ -191,7 +192,8 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                                     empty_string_filtering.ALIAS,
                                     filter_apidef.ALIAS,
                                     port_mac_address_regenerate.ALIAS,
-                                    pbe_ext.ALIAS]
+                                    pbe_ext.ALIAS,
+                                    agent_resources_synced.ALIAS]
 
     # List of agent types for which all binding_failed ports should try to be
     # rebound when agent revive

neutron/tests/unit/objects/test_agent.py

@@ -73,3 +73,9 @@ class AgentDbObjectTestCase(obj_test_base.BaseDbObjectTestCase,
 
         db_fields = obj.modify_fields_to_db(obj)
         self.assertIsNone(db_fields['resource_versions'])
+
+    def test_resources_synced_10(self):
+        obj = agent.Agent()
+        primitive = obj.obj_to_primitive(target_version='1.0')
+        self.assertNotIn(
+            'resources_synced', primitive['versioned_object.data'])

neutron/tests/unit/objects/test_objects.py

@@ -27,7 +27,7 @@ from neutron.tests import base as test_base
 # alphabetic order.
 object_data = {
     'AddressScope': '1.0-dd0dfdb67775892d3adc090e28e43bd8',
-    'Agent': '1.0-7106cb40117a8d1f042545796ed8787d',
+    'Agent': '1.1-64b670752d57b3c7602cb136e0338507',
     'AllowedAddressPair': '1.0-9f9186b6f952fbf31d257b0458b852c0',
     'AutoAllocatedTopology': '1.0-74642e58c53bf3610dc224c59f81b242',
     'DefaultSecurityGroup': '1.0-971520cb2e0ec06d747885a0cf78347f',