diff --git a/nova/conductor/manager.py b/nova/conductor/manager.py
index 8e9cf9c49aaf..39cbf428e541 100644
--- a/nova/conductor/manager.py
+++ b/nova/conductor/manager.py
@@ -20,6 +20,7 @@ import functools
 import sys
 
 from oslo_config import cfg
+from oslo_db import exception as db_exc
 from oslo_log import log as logging
 import oslo_messaging as messaging
 from oslo_serialization import jsonutils
@@ -77,7 +78,12 @@ def targets_cell(fn):
         except exception.InstanceMappingNotFound:
             LOG.error('InstanceMapping not found, unable to target cell',
                       instance=instance)
-            im = None
+        except db_exc.CantStartEngineError:
+            # Check to see if we can ignore API DB connection failures
+            # because we might already be in the cell conductor.
+            with excutils.save_and_reraise_exception() as err_ctxt:
+                if CONF.api_database.connection is None:
+                    err_ctxt.reraise = False
         else:
             LOG.debug('Targeting cell %(cell)s for conductor method %(meth)s',
                       {'cell': im.cell_mapping.identity,
diff --git a/nova/tests/unit/conductor/test_conductor.py b/nova/tests/unit/conductor/test_conductor.py
index 896f6ec3247b..e19d0b19da9a 100644
--- a/nova/tests/unit/conductor/test_conductor.py
+++ b/nova/tests/unit/conductor/test_conductor.py
@@ -18,6 +18,7 @@
 import copy
 
 import mock
+from oslo_db import exception as db_exc
 import oslo_messaging as messaging
 from oslo_serialization import jsonutils
 from oslo_utils.fixture import uuidsentinel as uuids
@@ -3315,6 +3316,41 @@ class ConductorTaskRPCAPITestCase(_BaseTaskTestCase,
                          test(None, ctxt, inst))
         mock_im.assert_called_once_with(ctxt, inst.uuid)
 
+    @mock.patch.object(objects.InstanceMapping, 'get_by_instance_uuid',
+                       side_effect=db_exc.CantStartEngineError)
+    def test_targets_cell_no_api_db_conn_noop(self, mock_im):
+        """Tests that targets_cell noops on CantStartEngineError if the API
+        DB is not configured because we assume we're in the cell conductor.
+        """
+        self.flags(connection=None, group='api_database')
+
+        @conductor_manager.targets_cell
+        def _test(self, context, instance):
+            return mock.sentinel.iransofaraway
+
+        ctxt = mock.MagicMock()
+        inst = mock.MagicMock()
+        self.assertEqual(mock.sentinel.iransofaraway,
+                         _test(None, ctxt, inst))
+        mock_im.assert_called_once_with(ctxt, inst.uuid)
+
+    @mock.patch.object(objects.InstanceMapping, 'get_by_instance_uuid',
+                       side_effect=db_exc.CantStartEngineError)
+    def test_targets_cell_no_api_db_conn_reraise(self, mock_im):
+        """Tests that targets_cell reraises CantStartEngineError if the
+        API DB is configured.
+        """
+        self.flags(connection='mysql://dbhost?nova_api', group='api_database')
+
+        @conductor_manager.targets_cell
+        def _test(self, context, instance):
+            return mock.sentinel.iransofaraway
+
+        ctxt = mock.MagicMock()
+        inst = mock.MagicMock()
+        self.assertRaises(db_exc.CantStartEngineError, _test, None, ctxt, inst)
+        mock_im.assert_called_once_with(ctxt, inst.uuid)
+
     def test_schedule_and_build_instances_with_tags(self):
 
         build_request = fake_build_request.fake_req_obj(self.context)