gistfile1.txt

diff --git a/ceilometer/agent/plugin_base.py b/ceilometer/agent/plugin_base.py
index 3cae66c..5d8155f 100644
--- a/ceilometer/agent/plugin_base.py
+++ b/ceilometer/agent/plugin_base.py
@@ -93,7 +93,7 @@ class NotificationBase(PluginBase):
         super(NotificationBase, self).__init__()
         # NOTE(gordc): this is filter rule used by oslo.messaging to dispatch
         # messages to an endpoint.
-        if self.event_types is not None:
+        if self.event_types and self.event_types is not []:
             self.filter_rule = oslo_messaging.NotificationFilter(
                 event_type='|'.join(self.event_types))
         self.manager = manager
diff --git a/ceilometer/meter/notifications.py b/ceilometer/meter/notifications.py
index b9584d7..0996ff3 100644
--- a/ceilometer/meter/notifications.py
+++ b/ceilometer/meter/notifications.py
@@ -24,6 +24,7 @@ import oslo_messaging
 from ceilometer.agent import plugin_base
 from ceilometer.i18n import _LE
 from ceilometer import sample
+from ceilometer import service
 
 OPTS = [
     cfg.StrOpt('meter_definitions_cfg_file',
@@ -91,6 +92,7 @@ class MeterDefinition(object):
 
 
 def get_config_file():
+    service.prepare_service([])
     config_file = cfg.CONF.meter.meter_definitions_cfg_file
     if not os.path.exists(config_file):
         config_file = cfg.CONF.find_file(config_file)
@@ -134,13 +136,15 @@ def setup_meters_config():
 
 
 def load_definitions(config_def):
+    if not config_def:
+        return []
     return [MeterDefinition(event_def)
             for event_def in reversed(config_def['metric'])]
 
 
 class ProcessMeterNotifications(plugin_base.NotificationBase):
 
-    event_types = None
+    event_types = []
 
     def __init__(self, manager):
         super(ProcessMeterNotifications, self).__init__(manager)