Merge "Make host_manager use scatter-gather and ignore down cells"

nova/scheduler/host_manager.py

@@ -612,24 +612,29 @@ def _get_computes_for_cells(self, context, cells, compute_uuids=None):
          - services is a dict of services indexed by hostname
         """
 
+        def targeted_operation(cctxt):
+            services = objects.ServiceList.get_by_binary(
+                cctxt, 'nova-compute', include_disabled=True)
+            if compute_uuids is None:
+                return services, objects.ComputeNodeList.get_all(cctxt)
+            else:
+                return services, objects.ComputeNodeList.get_all_by_uuids(
+                    cctxt, compute_uuids)
+
+        results = context_module.scatter_gather_cells(context, cells, 60,
+                                                      targeted_operation)
         compute_nodes = collections.defaultdict(list)
         services = {}
-        for cell in cells:
-            LOG.debug('Getting compute nodes and services for cell %(cell)s',
-                      {'cell': cell.identity})
-            with context_module.target_cell(context, cell) as cctxt:
-                if compute_uuids is None:
-                    compute_nodes[cell.uuid].extend(
-                        objects.ComputeNodeList.get_all(cctxt))
-                else:
-                    compute_nodes[cell.uuid].extend(
-                        objects.ComputeNodeList.get_all_by_uuids(
-                            cctxt, compute_uuids))
-                services.update(
-                    {service.host: service
-                     for service in objects.ServiceList.get_by_binary(
-                             cctxt, 'nova-compute',
-                             include_disabled=True)})
+        for cell_uuid, result in results.items():
+            if result is context_module.raised_exception_sentinel:
+                LOG.warning('Failed to get computes for cell %s', cell_uuid)
+            elif result is context_module.did_not_respond_sentinel:
+                LOG.warning('Timeout getting computes for cell %s', cell_uuid)
+            else:
+                _services, _compute_nodes = result
+                compute_nodes[cell_uuid].extend(_compute_nodes)
+                services.update({service.host: service
+                                 for service in _services})
         return compute_nodes, services
 
     def refresh_cells_caches(self):

nova/tests/unit/scheduler/test_host_manager.py

@@ -1038,6 +1038,21 @@ def fake_set_target(context, cell):
         mock_sl.assert_called_once_with(mock.sentinel.cctxt, 'nova-compute',
                                         include_disabled=True)
 
+    @mock.patch('nova.context.scatter_gather_cells')
+    def test_get_computes_for_cells_failures(self, mock_sg):
+        mock_sg.return_value = {
+            uuids.cell1: ([mock.MagicMock(host='a'), mock.MagicMock(host='b')],
+                          [mock.sentinel.c1n1, mock.sentinel.c1n2]),
+            uuids.cell2: nova_context.did_not_respond_sentinel,
+            uuids.cell3: nova_context.raised_exception_sentinel,
+        }
+        context = nova_context.RequestContext('fake', 'fake')
+        cns, srv = self.host_manager._get_computes_for_cells(context, [])
+
+        self.assertEqual({uuids.cell1: [mock.sentinel.c1n1,
+                                        mock.sentinel.c1n2]}, cns)
+        self.assertEqual(['a', 'b'], sorted(srv.keys()))
+
 
 class HostManagerChangedNodesTestCase(test.NoDBTestCase):
     """Test case for HostManager class."""