diff --git a/watcher/datasources/ceilometer.py b/watcher/datasources/ceilometer.py
index 913b4aff2..b04608bc9 100644
--- a/watcher/datasources/ceilometer.py
+++ b/watcher/datasources/ceilometer.py
@@ -164,7 +164,7 @@ class CeilometerHelper(base.DataSourceBase):
 
         meter = self.METRIC_MAP.get(meter_name)
         if meter is None:
-            raise exception.NoSuchMetric()
+            raise exception.MetricNotAvailable(metric=meter_name)
 
         if aggregate == 'mean':
             aggregate = 'avg'
diff --git a/watcher/datasources/gnocchi.py b/watcher/datasources/gnocchi.py
index 89615403d..02a7998a6 100644
--- a/watcher/datasources/gnocchi.py
+++ b/watcher/datasources/gnocchi.py
@@ -75,7 +75,7 @@ class GnocchiHelper(base.DataSourceBase):
 
         meter = self.METRIC_MAP.get(meter_name)
         if meter is None:
-            raise exception.NoSuchMetric()
+            raise exception.MetricNotAvailable(metric=meter_name)
 
         if aggregate == 'count':
             aggregate = 'mean'
diff --git a/watcher/datasources/monasca.py b/watcher/datasources/monasca.py
index c4818d8c7..a2f5b8917 100644
--- a/watcher/datasources/monasca.py
+++ b/watcher/datasources/monasca.py
@@ -92,7 +92,7 @@ class MonascaHelper(base.DataSourceBase):
 
         meter = self.METRIC_MAP.get(meter_name)
         if meter is None:
-            raise exception.NoSuchMetric()
+            raise exception.MetricNotAvailable(metric=meter_name)
 
         if aggregate == 'mean':
             aggregate = 'avg'
diff --git a/watcher/tests/datasources/test_ceilometer_helper.py b/watcher/tests/datasources/test_ceilometer_helper.py
index 75cbc1b41..9bebbebf8 100644
--- a/watcher/tests/datasources/test_ceilometer_helper.py
+++ b/watcher/tests/datasources/test_ceilometer_helper.py
@@ -20,6 +20,7 @@ from __future__ import unicode_literals
 import mock
 
 from watcher.common import clients
+from watcher.common import exception
 from watcher.datasources import ceilometer as ceilometer_helper
 from watcher.tests import base
 
@@ -70,6 +71,29 @@ class TestCeilometerHelper(base.BaseTestCase):
         )
         self.assertEqual(expected_result, val)
 
+    def test_statistic_aggregation_metric_unavailable(self, mock_ceilometer):
+        helper = ceilometer_helper.CeilometerHelper()
+
+        # invalidate instance_cpu_usage in metric map
+        original_metric_value = helper.METRIC_MAP.get('instance_cpu_usage')
+        helper.METRIC_MAP.update(
+            instance_cpu_usage=None
+        )
+
+        self.assertRaises(
+            exception.MetricNotAvailable,
+            helper.statistic_aggregation, resource=mock.Mock(id="INSTANCE_ID"),
+            resource_type='instance', meter_name="instance_cpu_usage",
+            period="7300",
+            granularity=None
+        )
+
+        # restore the metric map as it is a static attribute that does not get
+        # restored between unit tests!
+        helper.METRIC_MAP.update(
+            instance_cpu_usage=original_metric_value
+        )
+
     def test_get_host_cpu_usage(self, mock_ceilometer):
         self.helper.get_host_cpu_usage('compute1', 600, 'mean')
         self.mock_aggregation.assert_called_once_with(
diff --git a/watcher/tests/datasources/test_gnocchi_helper.py b/watcher/tests/datasources/test_gnocchi_helper.py
index 8e0949299..ea8ea91ac 100644
--- a/watcher/tests/datasources/test_gnocchi_helper.py
+++ b/watcher/tests/datasources/test_gnocchi_helper.py
@@ -18,6 +18,7 @@ import mock
 from oslo_config import cfg
 
 from watcher.common import clients
+from watcher.common import exception
 from watcher.datasources import gnocchi as gnocchi_helper
 from watcher.tests import base
 
@@ -57,6 +58,28 @@ class TestGnocchiHelper(base.BaseTestCase):
         )
         self.assertEqual(expected_result, result)
 
+    def test_statistic_aggregation_metric_unavailable(self, mock_gnocchi):
+        helper = gnocchi_helper.GnocchiHelper()
+
+        # invalidate instance_cpu_usage in metric map
+        original_metric_value = helper.METRIC_MAP.get('instance_cpu_usage')
+        helper.METRIC_MAP.update(
+            instance_cpu_usage=None
+        )
+
+        self.assertRaises(
+            exception.MetricNotAvailable, helper.statistic_aggregation,
+            resource=mock.Mock(id='16a86790-327a-45f9-bc82-45839f062fdc'),
+            resource_type='instance', meter_name='instance_cpu_usage',
+            period=300, granularity=360, aggregate='mean',
+        )
+
+        # restore the metric map as it is a static attribute that does not get
+        # restored between unit tests!
+        helper.METRIC_MAP.update(
+            instance_cpu_usage=original_metric_value
+        )
+
     def test_get_host_cpu_usage(self, mock_gnocchi):
         self.helper.get_host_cpu_usage('compute1', 600, 'mean', 300)
         self.mock_aggregation.assert_called_once_with(
diff --git a/watcher/tests/datasources/test_monasca_helper.py b/watcher/tests/datasources/test_monasca_helper.py
index c10f5db74..77f08db11 100644
--- a/watcher/tests/datasources/test_monasca_helper.py
+++ b/watcher/tests/datasources/test_monasca_helper.py
@@ -18,6 +18,7 @@ import mock
 from oslo_config import cfg
 
 from watcher.common import clients
+from watcher.common import exception
 from watcher.datasources import monasca as monasca_helper
 from watcher.tests import base
 
@@ -65,6 +66,28 @@ class TestMonascaHelper(base.BaseTestCase):
         )
         self.assertEqual(0.6, result)
 
+    def test_statistic_aggregation_metric_unavailable(self, mock_monasca):
+        helper = monasca_helper.MonascaHelper()
+
+        # invalidate host_cpu_usage in metric map
+        original_metric_value = helper.METRIC_MAP.get('host_cpu_usage')
+        helper.METRIC_MAP.update(
+            host_cpu_usage=None
+        )
+
+        self.assertRaises(
+            exception.MetricNotAvailable, helper.statistic_aggregation,
+            resource=mock.Mock(id='NODE_UUID'), resource_type='compute_node',
+            meter_name='host_cpu_usage', period=7200, granularity=300,
+            aggregate='mean',
+        )
+
+        # restore the metric map as it is a static attribute that does not get
+        # restored between unit tests!
+        helper.METRIC_MAP.update(
+            instance_cpu_usage=original_metric_value
+        )
+
     def test_check_availability(self, mock_monasca):
         monasca = mock.MagicMock()
         monasca.metrics.list.return_value = True