Merge "Don't throw exception when missing metrics"

watcher/decision_engine/datasources/base.py

@@ -19,8 +19,6 @@ import time
 from oslo_config import cfg
 from oslo_log import log
 
-from watcher.common import exception
-
 CONF = cfg.CONF
 LOG = log.getLogger(__name__)
 
@@ -79,7 +77,6 @@ class DataSourceBase(object):
                 LOG.warning("Retry {0} of {1} while retrieving metrics retry "
                             "in {2} seconds".format(i+1, num_retries, timeout))
                 time.sleep(timeout)
-        raise exception.DataSourceNotAvailable(datasource=self.NAME)
 
     @abc.abstractmethod
     def query_retry_reset(self, exception_instance):

watcher/decision_engine/datasources/ceilometer.py

@@ -136,19 +136,18 @@ class CeilometerHelper(base.DataSourceBase):
 
     def list_metrics(self):
         """List the user's meters."""
-        try:
-            meters = self.query_retry(f=self.ceilometer.meters.list)
-        except Exception:
+        meters = self.query_retry(f=self.ceilometer.meters.list)
+        if not meters:
             return set()
         else:
             return meters
 
     def check_availability(self):
-        try:
-            self.query_retry(self.ceilometer.resources.list)
-        except Exception:
+        status = self.query_retry(self.ceilometer.resources.list)
+        if status:
+            return 'available'
+        else:
             return 'not available'
-        return 'available'
 
     def query_sample(self, meter_name, query, limit=1):
         return self.query_retry(f=self.ceilometer.samples.list,

watcher/decision_engine/datasources/gnocchi.py

@@ -52,17 +52,16 @@ class GnocchiHelper(base.DataSourceBase):
         self.gnocchi = self.osc.gnocchi()
 
     def check_availability(self):
-        try:
-            self.query_retry(self.gnocchi.status.get)
-        except Exception:
+        status = self.query_retry(self.gnocchi.status.get)
+        if status:
+            return 'available'
+        else:
             return 'not available'
-        return 'available'
 
     def list_metrics(self):
         """List the user's meters."""
-        try:
-            response = self.query_retry(f=self.gnocchi.metric.list)
-        except Exception:
+        response = self.query_retry(f=self.gnocchi.metric.list)
+        if not response:
             return set()
         else:
             return set([metric['name'] for metric in response])
@@ -91,8 +90,9 @@ class GnocchiHelper(base.DataSourceBase):
                 f=self.gnocchi.resource.search, **kwargs)
 
             if not resources:
-                raise exception.ResourceNotFound(name='gnocchi',
-                                                 id=resource_id)
+                LOG.warning("The {0} resource {1} could not be "
+                            "found".format(self.NAME, resource_id))
+                return
 
             resource_id = resources[0]['id']
 
@@ -110,6 +110,7 @@ class GnocchiHelper(base.DataSourceBase):
         statistics = self.query_retry(
             f=self.gnocchi.metric.get_measures, **kwargs)
 
+        return_value = None
         if statistics:
             # return value of latest measure
             # measure has structure [time, granularity, value]
@@ -120,7 +121,7 @@ class GnocchiHelper(base.DataSourceBase):
                 # 1/10 th of actual CFM
                 return_value *= 10
 
-            return return_value
+        return return_value
 
     def get_host_cpu_usage(self, resource, period, aggregate,
                            granularity=300):

watcher/decision_engine/datasources/grafana.py

@@ -179,6 +179,9 @@ class GrafanaHelper(base.DataSourceBase):
         kwargs = {k: v for k, v in raw_kwargs.items() if k and v}
 
         resp = self.query_retry(self._request, **kwargs)
+        if not resp:
+            LOG.warning("Datasource {0} is not available.".format(self.NAME))
+            return
 
         result = translator.extract_result(resp.content)
 

watcher/decision_engine/datasources/monasca.py

@@ -73,11 +73,11 @@ class MonascaHelper(base.DataSourceBase):
             self.monasca = self.osc.monasca()
 
     def check_availability(self):
-        try:
-            self.query_retry(self.monasca.metrics.list)
-        except Exception:
+        result = self.query_retry(self.monasca.metrics.list)
+        if result:
+            return 'available'
+        else:
             return 'not available'
-        return 'available'
 
     def list_metrics(self):
         # TODO(alexchadin): this method should be implemented in accordance to

watcher/tests/decision_engine/datasources/test_base.py

@@ -19,7 +19,6 @@
 import mock
 from oslo_config import cfg
 
-from watcher.common import exception
 from watcher.decision_engine.datasources import base as datasource
 from watcher.tests import base
 
@@ -61,9 +60,8 @@ class TestBaseDatasourceHelper(base.BaseTestCase):
         helper = datasource.DataSourceBase()
         helper.query_retry_reset = mock.Mock()
 
-        # Maximum number of retries exceeded query_retry should raise error
-        self.assertRaises(exception.DataSourceNotAvailable,
-                          helper.query_retry, f=method)
+        # Maximum number of retries exceeded query_retry should return None
+        self.assertIsNone(helper.query_retry(f=method))
         # query_retry_reset should be called twice
         helper.query_retry_reset.assert_has_calls(
             [mock.call(exc), mock.call(exc)])

watcher/tests/decision_engine/datasources/test_grafana_helper.py

@@ -132,11 +132,7 @@ class TestGrafana(base.BaseTestCase):
 
         t_grafana = grafana.GrafanaHelper(osc=mock.Mock())
 
-        self.assertRaises(
-            exception.DataSourceNotAvailable,
-            t_grafana.get_host_cpu_usage,
-            self.m_compute_node
-        )
+        self.assertIsNone(t_grafana.get_host_cpu_usage(self.m_compute_node))
 
     def test_no_metric_raise_error(self):
         """Test raising error when specified meter does not exist"""