diff --git a/panko/event/storage/impl_mongodb.py b/panko/event/storage/impl_mongodb.py
index c2ca7fe0..320516d7 100644
--- a/panko/event/storage/impl_mongodb.py
+++ b/panko/event/storage/impl_mongodb.py
@@ -12,7 +12,6 @@
 # under the License.
 """MongoDB storage backend"""
 
-from oslo_config import cfg
 from oslo_log import log
 import pymongo
 
@@ -88,21 +87,19 @@ class Connection(pymongo_base.Connection):
              ('timestamp', pymongo.ASCENDING)],
             name='event_type_idx'
         )
-        ttl = cfg.CONF.database.event_time_to_live
-        self.update_ttl(ttl, 'event_ttl', 'timestamp', self.db.event)
 
     def clear(self):
         self.conn.drop_database(self.db.name)
         # Connection will be reopened automatically if needed
         self.conn.close()
 
-    @staticmethod
-    def clear_expired_event_data(ttl):
+    def clear_expired_event_data(self, ttl):
         """Clear expired data from the backend storage system.
 
         Clearing occurs according to the time-to-live.
 
         :param ttl: Number of seconds to keep records for.
         """
-        LOG.debug("Clearing expired event data is based on native "
-                  "MongoDB time to live feature and going in background.")
+        self.update_ttl(ttl, 'event_ttl', 'timestamp', self.db.event)
+        LOG.info("Clearing expired event data is based on native "
+                 "MongoDB time to live feature and going in background.")
diff --git a/panko/tests/functional/storage/test_impl_mongodb.py b/panko/tests/functional/storage/test_impl_mongodb.py
index 3c1d5f33..efbc0211 100644
--- a/panko/tests/functional/storage/test_impl_mongodb.py
+++ b/panko/tests/functional/storage/test_impl_mongodb.py
@@ -29,40 +29,26 @@ from panko.tests import db as tests_db
 @tests_db.run_with('mongodb')
 class IndexTest(tests_db.TestBase):
 
-    def _test_ttl_index_absent(self, conn, coll_name, ttl_opt):
-        # create a fake index and check it is deleted
-        coll = getattr(conn.db, coll_name)
-        index_name = '%s_ttl' % coll_name
-        self.CONF.set_override(ttl_opt, -1, group='database')
-        conn.upgrade()
-        self.assertNotIn(index_name, coll.index_information())
-
-        self.CONF.set_override(ttl_opt, 456789, group='database')
-        conn.upgrade()
-        self.assertEqual(456789,
-                         coll.index_information()
-                         [index_name]['expireAfterSeconds'])
-
     def test_event_ttl_index_absent(self):
-        self._test_ttl_index_absent(self.event_conn, 'event',
-                                    'event_time_to_live')
+        # create a fake index and check it is deleted
+        self.event_conn.clear_expired_event_data(-1)
+        self.assertNotIn("event_ttl",
+                         self.event_conn.db.event.index_information())
 
-    def _test_ttl_index_present(self, conn, coll_name, ttl_opt):
-        coll = getattr(conn.db, coll_name)
-        self.CONF.set_override(ttl_opt, 456789, group='database')
-        conn.upgrade()
-        index_name = '%s_ttl' % coll_name
+        self.event_conn.clear_expired_event_data(456789)
         self.assertEqual(456789,
-                         coll.index_information()
-                         [index_name]['expireAfterSeconds'])
-
-        self.CONF.set_override(ttl_opt, -1, group='database')
-        conn.upgrade()
-        self.assertNotIn(index_name, coll.index_information())
+                         self.event_conn.db.event.index_information()
+                         ["event_ttl"]['expireAfterSeconds'])
 
     def test_event_ttl_index_present(self):
-        self._test_ttl_index_present(self.event_conn, 'event',
-                                     'event_time_to_live')
+        self.event_conn.clear_expired_event_data(456789)
+        self.assertEqual(456789,
+                         self.event_conn.db.event.index_information()
+                         ["event_ttl"]['expireAfterSeconds'])
+
+        self.event_conn.clear_expired_event_data(-1)
+        self.assertNotIn("event_ttl",
+                         self.event_conn.db.event.index_information())
 
 
 class CapabilitiesTest(test_base.BaseTestCase):