Merge "gnocchi: percent_of_overlap=0 for agg. alarms"

aodh/api/controllers/v2/alarm_rules/gnocchi.py

@@ -123,7 +123,10 @@ class AggregationMetricByResourcesLookupRule(AlarmGnocchiThresholdRule):
     "The name of the metric"
 
     query = wsme.wsattr(wtypes.text, mandatory=True)
-    "The query to filter the metric"
+    ('The query to filter the metric, Don\'t forget to filter out '
+     'deleted resources (example: {"and": [{"=": {"ended_at": null}}, ...]}), '
+     'Otherwise Gnocchi will try to create the aggregate against obsolete '
+     'resources')
 
     resource_type = wsme.wsattr(wtypes.text, mandatory=True)
     "The resource type"

aodh/evaluator/gnocchi.py

@@ -60,6 +60,14 @@ class GnocchiThresholdEvaluator(threshold.ThresholdEvaluator):
             req['url'] += "/aggregation/resource/%s/metric/%s" % (
                 alarm.rule['resource_type'], alarm.rule['metric'])
             req['data'] = alarm.rule['query']
+            # FIXME(sileht): In case of a heat autoscaling stack decide to
+            # delete an instance, the gnocchi metrics associated to this
+            # instance will be no more updated and when the alarm will ask
+            # for the aggregation, gnocchi will raise a 'No overlap' exception.
+            # So temporary set 'percent_of_overlap' to 0 to disable the
+            # gnocchi checks about missing points. For more detail see:
+            #   https://bugs.launchpad.net/gnocchi/+bug/1479429
+            req['params']['percent_of_overlap'] = 0
 
         elif alarm.type == 'gnocchi_aggregation_by_metrics_threshold':
             req['url'] += "/aggregation/metric"

aodh/tests/evaluator/test_gnocchi.py

@@ -227,7 +227,8 @@ class TestGnocchiThresholdEvaluate(base.TestEvaluatorBase):
             mock.call(url='http://localhost:8041/v1/aggregation/resource/'
                       'instance/metric/cpu_util',
                       params={'aggregation': 'mean',
-                              'start': start_alarm3, 'end': end},
+                              'start': start_alarm3, 'end': end,
+                              'percent_of_overlap': 0},
                       data='{"=": {"server_group": "my_autoscaling_group"}}',
                       headers=expected_headers),
             ],