diff --git a/swh/storage/tests/test_server.py b/swh/storage/tests/test_server.py
index e2b2567b..f516f993 100644
--- a/swh/storage/tests/test_server.py
+++ b/swh/storage/tests/test_server.py
@@ -1,175 +1,175 @@
 # Copyright (C) 2019  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import copy
 import pytest
 import yaml
 
 from unittest.mock import patch
 
 from swh.storage.api.server import (
     load_and_check_config, send_metric,
     OPERATIONS_METRIC, OPERATIONS_UNIT_METRIC
 )
 
 
 def prepare_config_file(tmpdir, content, name='config.yml'):
     """Prepare configuration file in `$tmpdir/name` with content `content`.
 
     Args:
         tmpdir (LocalPath): root directory
         content (str/dict): Content of the file either as string or as a dict.
                             If a dict, converts the dict into a yaml string.
         name (str): configuration filename
 
     Returns
         path (str) of the configuration file prepared.
 
     """
     config_path = tmpdir / name
     if isinstance(content, dict):  # convert if needed
         content = yaml.dump(content)
     config_path.write_text(content, encoding='utf-8')
     # pytest on python3.5 does not support LocalPath manipulation, so
     # convert path to string
     return str(config_path)
 
 
 def test_load_and_check_config_no_configuration():
-    """Inexistant configuration files raises"""
+    """Inexistent configuration files raises"""
     with pytest.raises(EnvironmentError) as e:
         load_and_check_config(None)
 
     assert e.value.args[0] == 'Configuration file must be defined'
 
-    config_path = '/some/inexistant/config.yml'
+    config_path = '/some/inexistent/config.yml'
     with pytest.raises(FileNotFoundError) as e:
         load_and_check_config(config_path)
 
     assert e.value.args[0] == 'Configuration file %s does not exist' % (
         config_path, )
 
 
 def test_load_and_check_config_wrong_configuration(tmpdir):
     """Wrong configuration raises"""
     config_path = prepare_config_file(tmpdir, 'something: useless')
     with pytest.raises(KeyError) as e:
         load_and_check_config(config_path)
 
     assert e.value.args[0] == 'Missing \'%storage\' configuration'
 
 
 def test_load_and_check_config_remote_config_local_type_raise(tmpdir):
     """'local' configuration without 'local' storage raises"""
     config = {
         'storage': {
             'cls': 'remote',
             'args': {}
         }
     }
     config_path = prepare_config_file(tmpdir, config)
     with pytest.raises(ValueError) as e:
         load_and_check_config(config_path, type='local')
 
     assert (
         e.value.args[0] ==
         "The storage backend can only be started with a 'local' configuration"
     )
 
 
 def test_load_and_check_config_local_incomplete_configuration(tmpdir):
     """Incomplete 'local' configuration should raise"""
     config = {
         'storage': {
             'cls': 'local',
             'args': {
                 'db': 'database',
                 'objstorage': 'object_storage'
             }
         }
     }
 
     for key in ('db', 'objstorage'):
         c = copy.deepcopy(config)
         c['storage']['args'].pop(key)
         config_path = prepare_config_file(tmpdir, c)
         with pytest.raises(ValueError) as e:
             load_and_check_config(config_path)
 
         assert (
             e.value.args[0] ==
             "Invalid configuration; missing '%s' config entry" % key
         )
 
 
 def test_load_and_check_config_local_config_fine(tmpdir):
     """'Remote configuration is fine"""
     config = {
         'storage': {
             'cls': 'local',
             'args': {
                 'db': 'db',
                 'objstorage': 'something',
             }
         }
     }
     config_path = prepare_config_file(tmpdir, config)
     cfg = load_and_check_config(config_path, type='local')
     assert cfg == config
 
 
 def test_load_and_check_config_remote_config_fine(tmpdir):
     """'Remote configuration is fine"""
     config = {
         'storage': {
             'cls': 'remote',
             'args': {}
         }
     }
     config_path = prepare_config_file(tmpdir, config)
     cfg = load_and_check_config(config_path, type='any')
 
     assert cfg == config
 
 
 def test_send_metric_unknown_unit():
     r = send_metric('content', count=10, method_name='content_add')
     assert r is False
     r = send_metric('sthg:add:bytes:extra', count=10, method_name='sthg_add')
     assert r is False
 
 
 def test_send_metric_no_value():
     r = send_metric('content:add', count=0, method_name='content_add')
     assert r is False
 
 
 @patch('swh.storage.api.server.statsd.increment')
 def test_send_metric_no_unit(mock_statsd):
     r = send_metric('content:add', count=10, method_name='content_add')
 
     mock_statsd.assert_called_with(OPERATIONS_METRIC, 10, tags={
         'endpoint': 'content_add',
         'object_type': 'content',
         'operation': 'add',
     })
 
     assert r
 
 
 @patch('swh.storage.api.server.statsd.increment')
 def test_send_metric_unit(mock_statsd):
     unit_ = 'bytes'
     r = send_metric('c:add:%s' % unit_, count=100, method_name='c_add')
 
     expected_metric = OPERATIONS_UNIT_METRIC.format(unit=unit_)
     mock_statsd.assert_called_with(
         expected_metric, 100, tags={
             'endpoint': 'c_add',
             'object_type': 'c',
             'operation': 'add',
         })
 
     assert r