diff --git a/watcher/datasource/ceilometer.py b/watcher/datasource/ceilometer.py
index c4b351625..6465ad60e 100644
--- a/watcher/datasource/ceilometer.py
+++ b/watcher/datasource/ceilometer.py
@@ -136,15 +136,15 @@ class CeilometerHelper(base.DataSourceBase):
             self.osc.reset_clients()
             self.ceilometer = self.osc.ceilometer()
             return f(*args, **kargs)
-        except Exception:
-            raise
+        except Exception as e:
+            LOG.exception(e)
 
     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,
@@ -162,9 +162,8 @@ 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
diff --git a/watcher/datasource/gnocchi.py b/watcher/datasource/gnocchi.py
index a41f79277..fb57deceb 100644
--- a/watcher/datasource/gnocchi.py
+++ b/watcher/datasource/gnocchi.py
@@ -24,7 +24,6 @@ from oslo_config import cfg
 from oslo_log import log
 
 from watcher.common import clients
-from watcher.common import exception
 from watcher.common import utils as common_utils
 from watcher.datasource import base
 
@@ -60,20 +59,18 @@ class GnocchiHelper(base.DataSourceBase):
             except Exception as e:
                 LOG.exception(e)
                 time.sleep(CONF.gnocchi_client.query_timeout)
-        raise exception.DataSourceNotAvailable(datasource='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])
@@ -106,8 +103,9 @@ 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']
 
diff --git a/watcher/datasource/monasca.py b/watcher/datasource/monasca.py
index 2847cc73f..3c1055fb2 100644
--- a/watcher/datasource/monasca.py
+++ b/watcher/datasource/monasca.py
@@ -19,11 +19,14 @@
 import datetime
 
 from monascaclient import exc
+from oslo_log import log
 
 from watcher.common import clients
 from watcher.common import exception
 from watcher.datasource import base
 
+LOG = log.getLogger(__name__)
+
 
 class MonascaHelper(base.DataSourceBase):
 
@@ -53,8 +56,8 @@ class MonascaHelper(base.DataSourceBase):
             self.osc.reset_clients()
             self.monasca = self.osc.monasca()
             return f(*args, **kwargs)
-        except Exception:
-            raise
+        except Exception as e:
+            LOG.exception(e)
 
     def _format_time_params(self, start_time, end_time, period):
         """Format time-related params to the correct Monasca format
@@ -78,11 +81,11 @@ class MonascaHelper(base.DataSourceBase):
         return start_timestamp, end_timestamp, period
 
     def check_availability(self):
-        try:
-            self.query_retry(self.monasca.metrics.list)
-        except Exception:
+        status = self.query_retry(self.monasca.metrics.list)
+        if status:
+            return 'available'
+        else:
             return 'not available'
-        return 'available'
 
     def list_metrics(self):
         # TODO(alexchadin): this method should be implemented in accordance to