Merge "CG creation should be scheduled on backend level"

cinder/scheduler/filter_scheduler.py

@@ -397,7 +397,10 @@ class FilterScheduler(driver.Scheduler):
                 new_weighed_hosts = []
                 for host1 in weighed_hosts:
                     for host2 in temp_weighed_hosts:
-                        if host1.obj.host == host2.obj.host:
+                        # Should schedule creation of CG on backend level,
+                        # not pool level.
+                        if (utils.extract_host(host1.obj.host) ==
+                                utils.extract_host(host2.obj.host)):
                             new_weighed_hosts.append(host1)
                 weighed_hosts = new_weighed_hosts
                 if not weighed_hosts:
@@ -410,6 +413,16 @@ class FilterScheduler(driver.Scheduler):
     def _schedule(self, context, request_spec, filter_properties=None):
         weighed_hosts = self._get_weighted_candidates(context, request_spec,
                                                       filter_properties)
+        # When we get the weighed_hosts, we clear those hosts whose backend
+        # is not same as consistencygroup's backend.
+        CG_backend = request_spec.get('CG_backend')
+        if weighed_hosts and CG_backend:
+            # Get host name including host@backend#pool info from
+            # weighed_hosts.
+            for host in weighed_hosts[::-1]:
+                backend = utils.extract_host(host.obj.host)
+                if backend != CG_backend:
+                    weighed_hosts.remove(host)
         if not weighed_hosts:
             LOG.warning(_LW('No weighed hosts found for volume '
                             'with properties: %s'),

cinder/tests/unit/scheduler/test_filter_scheduler.py

@@ -192,6 +192,37 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase):
         self.assertIsNotNone(weighed_host.obj)
         self.assertTrue(_mock_service_get_all_by_topic.called)
 
+    @mock.patch('cinder.db.service_get_all_by_topic')
+    def test_create_volume_clear_host_different_with_cg(self,
+                                                        _mock_service_get_all):
+        # Ensure we clear those hosts whose backend is not same as
+        # consistencygroup's backend.
+        sched = fakes.FakeFilterScheduler()
+        sched.host_manager = fakes.FakeHostManager()
+        fakes.mock_host_manager_db_calls(_mock_service_get_all)
+        fake_context = context.RequestContext('user', 'project')
+        request_spec = {'volume_properties': {'project_id': 1,
+                                              'size': 1},
+                        'volume_type': {'name': 'LVM_iSCSI'},
+                        'CG_backend': 'host@lvmdriver'}
+        weighed_host = sched._schedule(fake_context, request_spec, {})
+        self.assertIsNone(weighed_host)
+
+    @mock.patch('cinder.db.service_get_all_by_topic')
+    def test_create_volume_host_same_as_cg(self, _mock_service_get_all):
+        # Ensure we don't clear the host whose backend is same as
+        # consistencygroup's backend.
+        sched = fakes.FakeFilterScheduler()
+        sched.host_manager = fakes.FakeHostManager()
+        fakes.mock_host_manager_db_calls(_mock_service_get_all)
+        fake_context = context.RequestContext('user', 'project')
+        request_spec = {'volume_properties': {'project_id': 1,
+                                              'size': 1},
+                        'volume_type': {'name': 'LVM_iSCSI'},
+                        'CG_backend': 'host1'}
+        weighed_host = sched._schedule(fake_context, request_spec, {})
+        self.assertEqual('host1#lvm1', weighed_host.obj.host)
+
     def test_max_attempts(self):
         self.flags(scheduler_max_attempts=4)
 

cinder/tests/unit/volume/flows/test_create_volume_flow.py

@@ -50,14 +50,16 @@ class CreateVolumeFlowTestCase(test.TestCase):
         # called to avoid div by zero errors.
         self.counter = float(0)
 
+    @mock.patch('cinder.volume.utils.extract_host')
     @mock.patch('time.time', side_effect=time_inc)
     @mock.patch('cinder.objects.ConsistencyGroup.get_by_id')
-    def test_cast_create_volume(self, consistencygroup_get_by_id, mock_time):
+    def test_cast_create_volume(self, consistencygroup_get_by_id, mock_time,
+                                mock_extract_host):
         props = {}
-        consistencygroup_obj = \
-            fake_consistencygroup.fake_consistencyobject_obj(
-                self.ctxt, consistencygroup_id=1, host=None)
-        consistencygroup_get_by_id.return_value = consistencygroup_obj
+        cg_obj = (fake_consistencygroup.
+                  fake_consistencyobject_obj(self.ctxt, consistencygroup_id=1,
+                                             host='host@backend#pool'))
+        consistencygroup_get_by_id.return_value = cg_obj
         spec = {'volume_id': None,
                 'source_volid': None,
                 'snapshot_id': None,
@@ -90,6 +92,7 @@ class CreateVolumeFlowTestCase(test.TestCase):
 
         task._cast_create_volume(self.ctxt, spec, props)
         consistencygroup_get_by_id.assert_called_once_with(self.ctxt, 5)
+        mock_extract_host.assert_called_once_with('host@backend#pool')
 
     @mock.patch('cinder.volume.volume_types.is_encrypted')
     @mock.patch('cinder.volume.flows.api.create_volume.'

cinder/volume/flows/api/create_volume.py

@@ -27,6 +27,7 @@ from cinder import policy
 from cinder import quota
 from cinder import utils
 from cinder.volume.flows import common
+from cinder.volume import utils as vol_utils
 from cinder.volume import volume_types
 
 LOG = logging.getLogger(__name__)
@@ -697,8 +698,14 @@ class VolumeCastTask(flow_utils.CinderTask):
         cgsnapshot_id = request_spec['cgsnapshot_id']
 
         if cgroup_id:
+            # If cgroup_id existed, we should cast volume to the scheduler
+            # to choose a proper pool whose backend is same as CG's backend.
             cgroup = objects.ConsistencyGroup.get_by_id(context, cgroup_id)
-            host = cgroup.host
+            # FIXME(wanghao): CG_backend got added before request_spec was
+            # converted to versioned objects. We should make sure that this
+            # will be handled by object version translations once we add
+            # RequestSpec object.
+            request_spec['CG_backend'] = vol_utils.extract_host(cgroup.host)
         elif snapshot_id and CONF.snapshot_same_host:
             # NOTE(Rongze Zhu): A simple solution for bug 1008866.
             #