Merge "reset task_state after select_destinations failed."

nova/conductor/manager.py

@@ -318,7 +318,8 @@ class ComputeTaskManager(base.Base):
                 exception.HypervisorUnavailable,
                 exception.InstanceInvalidState,
                 exception.MigrationPreCheckError,
-                exception.LiveMigrationWithOldNovaNotSafe) as ex:
+                exception.LiveMigrationWithOldNovaNotSafe,
+                exception.MigrationSchedulerRPCError) as ex:
             with excutils.save_and_reraise_exception():
                 # TODO(johngarbutt) - eventually need instance actions here
                 _set_vm_state(context, instance, ex, instance.vm_state)

nova/conductor/tasks/live_migrate.py

@@ -13,6 +13,7 @@
 from oslo_config import cfg
 from oslo_log import log as logging
 import oslo_messaging as messaging
+import six
 
 from nova.compute import power_state
 from nova.conductor.tasks import base
@@ -177,8 +178,17 @@ class LiveMigrationTask(base.TaskBase):
             # scheduler.utils methods to directly use the RequestSpec object
             spec_obj = objects.RequestSpec.from_primitives(
                 self.context, request_spec, filter_properties)
-            host = self.scheduler_client.select_destinations(self.context,
-                            spec_obj)[0]['host']
+            try:
+                host = self.scheduler_client.select_destinations(self.context,
+                                spec_obj)[0]['host']
+            except messaging.RemoteError as ex:
+                # TODO(ShaoHe Feng) There maybe multi-scheduler, and the
+                # scheduling algorithm is R-R, we can let other scheduler try.
+                # Note(ShaoHe Feng) There are types of RemoteError, such as
+                # NoSuchMethod, UnsupportedVersion, we can distinguish it by
+                # ex.exc_type.
+                raise exception.MigrationSchedulerRPCError(
+                    reason=six.text_type(ex))
             try:
                 self._check_compatible_with_source_hypervisor(host)
                 self._call_livem_checks_on_host(host)

nova/exception.py

@@ -1321,6 +1321,10 @@ class MigrationPreCheckError(MigrationError):
     msg_fmt = _("Migration pre-check error: %(reason)s")
 
 
+class MigrationSchedulerRPCError(MigrationError):
+    msg_fmt = _("Migration select destinations error: %(reason)s")
+
+
 class MalformedRequestBody(NovaException):
     msg_fmt = _("Malformed message body: %(reason)s")
 

nova/tests/unit/conductor/tasks/test_live_migrate.py

@@ -16,6 +16,7 @@ import oslo_messaging as messaging
 
 from nova.compute import power_state
 from nova.compute import rpcapi as compute_rpcapi
+from nova.compute import vm_states
 from nova.conductor.tasks import live_migrate
 from nova import exception
 from nova import objects
@@ -38,6 +39,7 @@ class LiveMigrationTaskTestCase(test.NoDBTestCase):
                 host=self.instance_host,
                 uuid=self.instance_uuid,
                 power_state=power_state.RUNNING,
+                vm_state = vm_states.ACTIVE,
                 memory_mb=512,
                 image_ref=self.instance_image)
         self.instance = objects.Instance._from_db_object(
@@ -501,6 +503,24 @@ class LiveMigrationTaskTestCase(test.NoDBTestCase):
         self.mox.ReplayAll()
         self.assertRaises(exception.NoValidHost, self.task._find_destination)
 
+    @mock.patch("nova.utils.get_image_from_system_metadata")
+    @mock.patch("nova.scheduler.utils.build_request_spec")
+    @mock.patch("nova.scheduler.utils.setup_instance_group")
+    @mock.patch("nova.objects.RequestSpec.from_primitives")
+    def test_find_destination_with_remoteError(self,
+        m_from_primitives, m_setup_instance_group,
+        m_build_request_spec, m_get_image_from_system_metadata):
+        m_get_image_from_system_metadata.return_value = {'properties': {}}
+        m_build_request_spec.return_value = {}
+        fake_spec = objects.RequestSpec()
+        m_from_primitives.return_value = fake_spec
+        with mock.patch.object(self.task.scheduler_client,
+            'select_destinations') as m_select_destinations:
+            error = messaging.RemoteError()
+            m_select_destinations.side_effect = error
+            self.assertRaises(exception.MigrationSchedulerRPCError,
+                              self.task._find_destination)
+
     def test_call_livem_checks_on_host(self):
         with mock.patch.object(self.task.compute_rpcapi,
             'check_can_live_migrate_destination',

nova/tests/unit/conductor/test_conductor.py

@@ -1109,7 +1109,8 @@ class ConductorTaskTestCase(_BaseTaskTestCase, test_compute.BaseTestCase):
                exc.InvalidHypervisorType(),
                exc.InvalidCPUInfo(reason='dummy'),
                exc.UnableToMigrateToSelf(instance_id='dummy', host='dummy'),
-               exc.InvalidLocalStorage(path='dummy', reason='dummy')]
+               exc.InvalidLocalStorage(path='dummy', reason='dummy'),
+               exc.MigrationSchedulerRPCError(reason='dummy')]
         for ex in exs:
             self._test_migrate_server_deals_with_expected_exceptions(ex)