Don't update API cell on get_nwinfo

Every call to get_instance_nw_info() updates an instance's info_cache.
The purpose of this is to make sure we're constantly healing the
info_cache table.  However, this causes a lot of unneeded updates
traveling up to the API cell.  Cells has its own periodic task that
heals all instance data.

Fixes bug 1180304

Change-Id: I07774712a6358999fd1fdd0f5a90c6f05e3d8d6e

nova/cells/messaging.py

@@ -847,8 +847,8 @@ class _BroadcastMessageMethods(_BaseMessageMethods):
                 self.db.instance_create(message.ctxt, instance)
         if info_cache:
             try:
-                self.db.instance_info_cache_update(message.ctxt,
+                self.db.instance_info_cache_update(
-                        instance_uuid, info_cache, update_cells=False)
+                        message.ctxt, instance_uuid, info_cache)
             except exception.InstanceInfoCacheNotFound:
                 # Can happen if we try to update a deleted instance's
                 # network information.

nova/db/api.py

@@ -719,22 +719,13 @@ def instance_info_cache_get(context, instance_uuid):
     return IMPL.instance_info_cache_get(context, instance_uuid)
 
 
-def instance_info_cache_update(context, instance_uuid, values,
+def instance_info_cache_update(context, instance_uuid, values):
-        update_cells=True):
     """Update an instance info cache record in the table.
 
     :param instance_uuid: = uuid of info cache's instance
     :param values: = dict containing column values to update
     """
-    rv = IMPL.instance_info_cache_update(context, instance_uuid, values)
+    return IMPL.instance_info_cache_update(context, instance_uuid, values)
-    if update_cells:
-        try:
-            cells_rpcapi.CellsAPI().instance_info_cache_update_at_top(
-                    context, rv)
-        except Exception:
-            LOG.exception(_("Failed to notify cells of instance info "
-                            "cache update"))
-    return rv
 
 
 def instance_info_cache_delete(context, instance_uuid):

nova/network/api.py

@@ -21,6 +21,7 @@
 import functools
 import inspect
 
+from nova.cells import rpcapi as cells_rpcapi
 from nova.compute import flavors
 from nova.db import base
 from nova import exception
@@ -64,7 +65,8 @@ def refresh_cache(f):
 
 
 def update_instance_cache_with_nw_info(api, context, instance,
-                                       nw_info=None, conductor_api=None):
+                                       nw_info=None, conductor_api=None,
+                                       update_cells=True):
     try:
         if not isinstance(nw_info, network_model.NetworkInfo):
             nw_info = None
@@ -73,9 +75,20 @@ def update_instance_cache_with_nw_info(api, context, instance,
         # update cache
         cache = {'network_info': nw_info.json()}
         if conductor_api:
-            conductor_api.instance_info_cache_update(context, instance, cache)
+            rv = conductor_api.instance_info_cache_update(context,
+                                                          instance,
+                                                          cache)
         else:
-            api.db.instance_info_cache_update(context, instance['uuid'], cache)
+            rv = api.db.instance_info_cache_update(context,
+                                                   instance['uuid'],
+                                                   cache)
+        if update_cells:
+            cells_api = cells_rpcapi.CellsAPI()
+            try:
+                cells_api.instance_info_cache_update_at_top(context, rv)
+            except Exception:
+                LOG.exception(_("Failed to notify cells of instance info "
+                                "cache update"))
     except Exception:
         LOG.exception(_('Failed storing info cache'), instance=instance)
 
@@ -366,8 +379,13 @@ class API(base.Base):
     def get_instance_nw_info(self, context, instance, conductor_api=None):
         """Returns all network info related to an instance."""
         result = self._get_instance_nw_info(context, instance)
+        # NOTE(comstud): Don't update API cell with new info_cache every
+        # time we pull network info for an instance.  The periodic healing
+        # of info_cache causes too many cells messages.  Healing the API
+        # will happen separately.
         update_instance_cache_with_nw_info(self, context, instance,
-                                           result, conductor_api)
+                                           result, conductor_api,
+                                           update_cells=False)
         return result
 
     def _get_instance_nw_info(self, context, instance):

nova/tests/cells/test_cells_messaging.py

@@ -1033,8 +1033,7 @@ class CellsBroadcastMethodsTestCase(test.TestCase):
                                          expected_instance,
                                          update_cells=False)
         self.tgt_db_inst.instance_info_cache_update(self.ctxt, 'fake_uuid',
-                                                    expected_info_cache,
+                                                    expected_info_cache)
-                                                    update_cells=False)
         self.mox.ReplayAll()
 
         self.src_msg_runner.instance_update_at_top(self.ctxt, fake_instance)
@@ -1086,8 +1085,7 @@ class CellsBroadcastMethodsTestCase(test.TestCase):
                                          expected_instance,
                                          update_cells=False)
         self.tgt_db_inst.instance_info_cache_update(self.ctxt, 'fake_uuid',
-                                                    expected_info_cache,
+                                                    expected_info_cache)
-                                                    update_cells=False)
         self.mox.ReplayAll()
 
         self.src_msg_runner.instance_update_at_top(self.ctxt, fake_instance)