diff --git a/watcher/api/controllers/v1/types.py b/watcher/api/controllers/v1/types.py
index 302e8ced3..650e0d142 100644
--- a/watcher/api/controllers/v1/types.py
+++ b/watcher/api/controllers/v1/types.py
@@ -181,8 +181,9 @@ class MultiType(wtypes.UserType):
                 return value
         else:
             raise ValueError(
-                _("Wrong type. Expected '%(type)s', got '%(value)s'")
-                % {'type': self.types, 'value': type(value)})
+                _("Wrong type. Expected '%(type)s', got '%(value)s'"),
+                type=self.types, value=type(value)
+            )
 
 
 class JsonPatchType(wtypes.Base):
diff --git a/watcher/api/middleware/auth_token.py b/watcher/api/middleware/auth_token.py
index fe650fe98..942bc5a0e 100644
--- a/watcher/api/middleware/auth_token.py
+++ b/watcher/api/middleware/auth_token.py
@@ -40,10 +40,9 @@ class AuthTokenMiddleware(auth_token.AuthProtocol):
             self.public_api_routes = [re.compile(route_pattern_tpl % route_tpl)
                                       for route_tpl in public_api_routes]
         except re.error as e:
-            msg = _('Cannot compile public API routes: %s') % e
-
-            LOG.error(msg)
-            raise exception.ConfigInvalid(error_msg=msg)
+            LOG.exception(e)
+            raise exception.ConfigInvalid(
+                error_msg=_('Cannot compile public API routes'))
 
         super(AuthTokenMiddleware, self).__init__(app, conf)
 
diff --git a/watcher/applier/manager.py b/watcher/applier/manager.py
index 246d755da..00ef62475 100644
--- a/watcher/applier/manager.py
+++ b/watcher/applier/manager.py
@@ -89,5 +89,5 @@ class ApplierManager(MessagingCore):
             LOG.debug("type_event => %s" % str(event_type))
             LOG.debug("data       => %s" % str(data))
         except Exception as e:
-            LOG.error("evt %s" % e.message)
-            raise e
+            LOG.exception(e)
+            raise
diff --git a/watcher/applier/primitives/change_nova_service_state.py b/watcher/applier/primitives/change_nova_service_state.py
index 61d7f65f6..e43e2963b 100644
--- a/watcher/applier/primitives/change_nova_service_state.py
+++ b/watcher/applier/primitives/change_nova_service_state.py
@@ -20,7 +20,7 @@
 
 from oslo_config import cfg
 
-
+from watcher._i18n import _
 from watcher.applier.primitives.base import BasePrimitive
 from watcher.applier.primitives.wrapper.nova_wrapper import NovaWrapper
 from watcher.applier.promise import Promise
@@ -70,7 +70,8 @@ class ChangeNovaServiceState(BasePrimitive):
 
     def nova_manage_service(self, state):
         if state is None:
-            raise IllegalArgumentException("The target state is not defined")
+            raise IllegalArgumentException(
+                _("The target state is not defined"))
 
         keystone = KeystoneClient()
         wrapper = NovaWrapper(keystone.get_credentials(),
diff --git a/watcher/applier/rpcapi.py b/watcher/applier/rpcapi.py
index 016a78a6d..bae28074e 100644
--- a/watcher/applier/rpcapi.py
+++ b/watcher/applier/rpcapi.py
@@ -20,7 +20,6 @@ from oslo_config import cfg
 from oslo_log import log
 import oslo_messaging as om
 
-
 from watcher.applier.manager import APPLIER_MANAGER_OPTS
 from watcher.applier.manager import opt_group
 from watcher.common import exception
@@ -69,5 +68,5 @@ class ApplierAPI(MessagingCore):
         try:
             pass
         except Exception as e:
-            LOG.error("evt %s" % e.message)
-            raise e
+            LOG.exception(e)
+            raise
diff --git a/watcher/common/exception.py b/watcher/common/exception.py
index 7c6ae90b0..1fcd668ec 100644
--- a/watcher/common/exception.py
+++ b/watcher/common/exception.py
@@ -24,11 +24,9 @@ SHOULD include dedicated exception logging.
 
 from oslo_config import cfg
 from oslo_log import log as logging
-
 import six
 
-from watcher._i18n import _
-from watcher._i18n import _LE
+from watcher._i18n import _, _LE
 
 LOG = logging.getLogger(__name__)
 
@@ -43,7 +41,7 @@ CONF.register_opts(exc_log_opts)
 
 
 def _cleanse_dict(original):
-    """Strip all admin_password, new_pass, rescue_pass keys from a dict."""
+    """Strip all admin_password, new_pass, rescue_pass keys from a dict"""
     return dict((k, v) for k, v in six.iteritems(original) if "_pass" not in k)
 
 
@@ -55,7 +53,7 @@ class WatcherException(Exception):
     with the keyword arguments provided to the constructor.
 
     """
-    message = _("An unknown exception occurred.")
+    message = _("An unknown exception occurred")
     code = 500
     headers = {}
     safe = False
@@ -78,7 +76,7 @@ class WatcherException(Exception):
                 # log the issue and the kwargs
                 LOG.exception(_LE('Exception in string format operation'))
                 for name, value in six.iteritems(kwargs):
-                    LOG.error("%s: %s" % (name, value))
+                    LOG.error("%s: %s", name, value)
 
                 if CONF.fatal_exception_format_errors:
                     raise e
@@ -89,7 +87,7 @@ class WatcherException(Exception):
         super(WatcherException, self).__init__(message)
 
     def __str__(self):
-        """Encode to utf-8 then wsme api can consume it as well."""
+        """Encode to utf-8 then wsme api can consume it as well"""
         if not six.PY3:
             return unicode(self.args[0]).encode('utf-8')
         else:
@@ -106,39 +104,39 @@ class WatcherException(Exception):
 
 
 class NotAuthorized(WatcherException):
-    message = _("Not authorized.")
+    message = _("Not authorized")
     code = 403
 
 
 class OperationNotPermitted(NotAuthorized):
-    message = _("Operation not permitted.")
+    message = _("Operation not permitted")
 
 
 class Invalid(WatcherException):
-    message = _("Unacceptable parameters.")
+    message = _("Unacceptable parameters")
     code = 400
 
 
 class ObjectNotFound(WatcherException):
-    message = _("The %(name)s %(id)s could not be found.")
+    message = _("The %(name)s %(id)s could not be found")
 
 
 class Conflict(WatcherException):
-    message = _('Conflict.')
+    message = _('Conflict')
     code = 409
 
 
 class ResourceNotFound(ObjectNotFound):
-    message = _("The %(name)s resource %(id)s could not be found.")
+    message = _("The %(name)s resource %(id)s could not be found")
     code = 404
 
 
 class InvalidIdentity(Invalid):
-    message = _("Expected an uuid or int but received %(identity)s.")
+    message = _("Expected an uuid or int but received %(identity)s")
 
 
 class InvalidGoal(Invalid):
-    message = _("Goal %(goal)s is not defined in Watcher configuration file.")
+    message = _("Goal %(goal)s is not defined in Watcher configuration file")
 
 
 # Cannot be templated as the error syntax varies.
@@ -148,73 +146,73 @@ class InvalidParameterValue(Invalid):
 
 
 class InvalidUUID(Invalid):
-    message = _("Expected a uuid but received %(uuid)s.")
+    message = _("Expected a uuid but received %(uuid)s")
 
 
 class InvalidName(Invalid):
-    message = _("Expected a logical name but received %(name)s.")
+    message = _("Expected a logical name but received %(name)s")
 
 
 class InvalidUuidOrName(Invalid):
-    message = _("Expected a logical name or uuid but received %(name)s.")
+    message = _("Expected a logical name or uuid but received %(name)s")
 
 
 class AuditTemplateNotFound(ResourceNotFound):
-    message = _("AuditTemplate %(audit_template)s could not be found.")
+    message = _("AuditTemplate %(audit_template)s could not be found")
 
 
 class AuditTemplateAlreadyExists(Conflict):
     message = _("An audit_template with UUID %(uuid)s or name %(name)s "
-                "already exists.")
+                "already exists")
 
 
 class AuditTemplateReferenced(Invalid):
     message = _("AuditTemplate %(audit_template)s is referenced by one or "
-                "multiple audit.")
+                "multiple audit")
 
 
 class AuditNotFound(ResourceNotFound):
-    message = _("Audit %(audit)s could not be found.")
+    message = _("Audit %(audit)s could not be found")
 
 
 class AuditAlreadyExists(Conflict):
-    message = _("An audit with UUID %(uuid)s already exists.")
+    message = _("An audit with UUID %(uuid)s already exists")
 
 
 class AuditReferenced(Invalid):
     message = _("Audit %(audit)s is referenced by one or multiple action "
-                "plans.")
+                "plans")
 
 
 class ActionPlanNotFound(ResourceNotFound):
-    message = _("ActionPlan %(action plan)s could not be found.")
+    message = _("ActionPlan %(action plan)s could not be found")
 
 
 class ActionPlanAlreadyExists(Conflict):
-    message = _("An action plan with UUID %(uuid)s already exists.")
+    message = _("An action plan with UUID %(uuid)s already exists")
 
 
 class ActionPlanReferenced(Invalid):
     message = _("Action Plan %(action_plan)s is referenced by one or "
-                "multiple actions.")
+                "multiple actions")
 
 
 class ActionNotFound(ResourceNotFound):
-    message = _("Action %(action)s could not be found.")
+    message = _("Action %(action)s could not be found")
 
 
 class ActionAlreadyExists(Conflict):
-    message = _("An action with UUID %(uuid)s already exists.")
+    message = _("An action with UUID %(uuid)s already exists")
 
 
 class ActionReferenced(Invalid):
     message = _("Action plan %(action_plan)s is referenced by one or "
-                "multiple goals.")
+                "multiple goals")
 
 
 class ActionFilterCombinationProhibited(Invalid):
     message = _("Filtering actions on both audit and action-plan is "
-                "prohibited.")
+                "prohibited")
 
 
 class HTTPNotFound(ResourceNotFound):
@@ -232,8 +230,7 @@ class BaseException(Exception):
 
     def __init__(self, desc=""):
         if (not isinstance(desc, six.string_types)):
-            raise IllegalArgumentException(
-                "Description must be an instance of str")
+            raise ValueError(_("Description must be an instance of str"))
 
         desc = desc.strip()
 
@@ -243,7 +240,7 @@ class BaseException(Exception):
         return self._desc
 
     def get_message(self):
-        return "An exception occurred without a description."
+        return _("An exception occurred without a description")
 
     def __str__(self):
         return self.get_message()
@@ -251,10 +248,8 @@ class BaseException(Exception):
 
 class IllegalArgumentException(BaseException):
     def __init__(self, desc):
-        BaseException.__init__(self, desc)
-
-        if self._desc == "":
-            raise IllegalArgumentException("Description cannot be empty")
+        desc = desc or _("Description cannot be empty")
+        super(IllegalArgumentException, self).__init__(desc)
 
     def get_message(self):
         return self._desc
@@ -262,10 +257,8 @@ class IllegalArgumentException(BaseException):
 
 class NoSuchMetric(BaseException):
     def __init__(self, desc):
-        BaseException.__init__(self, desc)
-
-        if self._desc == "":
-            raise NoSuchMetric("No such metric")
+        desc = desc or _("No such metric")
+        super(NoSuchMetric, self).__init__(desc)
 
     def get_message(self):
         return self._desc
@@ -273,10 +266,8 @@ class NoSuchMetric(BaseException):
 
 class NoDataFound(BaseException):
     def __init__(self, desc):
-        BaseException.__init__(self, desc)
-
-        if self._desc == "":
-            raise NoSuchMetric("no rows were returned")
+        desc = desc or _("No rows were returned")
+        super(NoDataFound, self).__init__(desc)
 
     def get_message(self):
         return self._desc
@@ -287,11 +278,11 @@ class KeystoneFailure(WatcherException):
 
 
 class ClusterEmpty(WatcherException):
-    message = _("The list of hypervisor(s) in the cluster is empty.'")
+    message = _("The list of hypervisor(s) in the cluster is empty")
 
 
 class MetricCollectorNotDefined(WatcherException):
-    message = _("The metrics resource collector is not defined.'")
+    message = _("The metrics resource collector is not defined")
 
 
 class ClusterStateNotDefined(WatcherException):
@@ -301,12 +292,12 @@ class ClusterStateNotDefined(WatcherException):
 # Model
 
 class VMNotFound(WatcherException):
-    message = _("The VM could not be found.")
+    message = _("The VM could not be found")
 
 
 class HypervisorNotFound(WatcherException):
-    message = _("The hypervisor could not be found.")
+    message = _("The hypervisor could not be found")
 
 
 class MetaActionNotFound(WatcherException):
-    message = _("The Meta-Action could not be found.")
+    message = _("The Meta-Action could not be found")
diff --git a/watcher/common/keystone.py b/watcher/common/keystone.py
index 118655c31..e75f2a233 100644
--- a/watcher/common/keystone.py
+++ b/watcher/common/keystone.py
@@ -17,16 +17,15 @@
 # limitations under the License.
 #
 
+from keystoneclient.auth.identity import generic
+from keystoneclient import session as keystone_session
 from oslo_config import cfg
 from oslo_log import log
-
 from six.moves.urllib.parse import urljoin
 from six.moves.urllib.parse import urlparse
 
-from keystoneclient.auth.identity import generic
-from keystoneclient import session as keystone_session
-
-from watcher.common.exception import KeystoneFailure
+from watcher._i18n import _
+from watcher.common import exception
 
 
 LOG = log.getLogger(__name__)
@@ -56,8 +55,9 @@ class KeystoneClient(object):
     def get_endpoint(self, **kwargs):
         kc = self._get_ksclient()
         if not kc.has_service_catalog():
-            raise KeystoneFailure('No Keystone service catalog '
-                                  'loaded')
+            raise exception.KeystoneFailure(
+                _('No Keystone service catalog loaded')
+            )
         attr = None
         filter_value = None
         if kwargs.get('region_name'):
diff --git a/watcher/common/messaging/messaging_handler.py b/watcher/common/messaging/messaging_handler.py
index af2010438..7dad74556 100644
--- a/watcher/common/messaging/messaging_handler.py
+++ b/watcher/common/messaging/messaging_handler.py
@@ -15,14 +15,15 @@
 # limitations under the License.
 
 import socket
+import threading
 
 import eventlet
 from oslo_config import cfg
 from oslo_log import log
 import oslo_messaging as om
-from threading import Thread
-from watcher.common.rpc import JsonPayloadSerializer
-from watcher.common.rpc import RequestContextSerializer
+
+from watcher.common import rpc
+from watcher._i18n import _LE, _LW
 
 # NOTE:
 # Ubuntu 14.04 forces librabbitmq when kombu is used
@@ -35,7 +36,7 @@ LOG = log.getLogger(__name__)
 CONF = cfg.CONF
 
 
-class MessagingHandler(Thread):
+class MessagingHandler(threading.Thread):
 
     def __init__(self, publisher_id, topic_watcher, endpoint, version,
                  serializer=None):
@@ -67,7 +68,7 @@ class MessagingHandler(Thread):
         return self.__transport
 
     def build_notifier(self):
-        serializer = RequestContextSerializer(JsonPayloadSerializer())
+        serializer = rpc.RequestContextSerializer(rpc.JsonPayloadSerializer())
         return om.Notifier(
             self.__transport,
             publisher_id=self.publisher_id,
@@ -93,11 +94,11 @@ class MessagingHandler(Thread):
                 )
                 self.__server = self.build_server(target)
             else:
-                LOG.warn("you have no defined endpoint, "
-                         "so you can only publish events")
+                LOG.warn(
+                    _LW("No endpoint defined; can only publish events"))
         except Exception as e:
             LOG.exception(e)
-            LOG.error("configure : %s" % str(e.message))
+            LOG.error(_LE("Messaging configuration error"))
 
     def run(self):
         LOG.debug("configure MessagingHandler for %s" % self.topic_watcher)
@@ -107,7 +108,7 @@ class MessagingHandler(Thread):
             self.__server.start()
 
     def stop(self):
-        LOG.debug('Stop up server')
+        LOG.debug('Stopped server')
         self.__server.wait()
         self.__server.stop()
 
diff --git a/watcher/db/sqlalchemy/api.py b/watcher/db/sqlalchemy/api.py
index 4f982d2da..00332da2f 100644
--- a/watcher/db/sqlalchemy/api.py
+++ b/watcher/db/sqlalchemy/api.py
@@ -22,15 +22,14 @@ from oslo_db import exception as db_exc
 from oslo_db.sqlalchemy import session as db_session
 from oslo_db.sqlalchemy import utils as db_utils
 from oslo_log import log
-from sqlalchemy.orm.exc import MultipleResultsFound
-from sqlalchemy.orm.exc import NoResultFound
+from sqlalchemy.orm import exc
 
 from watcher import _i18n
 from watcher.common import exception
 from watcher.common import utils
 from watcher.db import api
 from watcher.db.sqlalchemy import models
-from watcher.objects.audit import AuditStatus
+from watcher.objects import audit as audit_objects
 
 CONF = cfg.CONF
 LOG = log.getLogger(__name__)
@@ -223,7 +222,7 @@ class Connection(api.BaseConnection):
                     raise exception.AuditTemplateNotFound(
                         audit_template=audit_template_id)
             return audit_template
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.AuditTemplateNotFound(
                 audit_template=audit_template_id)
 
@@ -238,7 +237,7 @@ class Connection(api.BaseConnection):
                     raise exception.AuditTemplateNotFound(
                         audit_template=audit_template_uuid)
             return audit_template
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.AuditTemplateNotFound(
                 audit_template=audit_template_uuid)
 
@@ -252,11 +251,11 @@ class Connection(api.BaseConnection):
                     raise exception.AuditTemplateNotFound(
                         audit_template=audit_template_name)
             return audit_template
-        except MultipleResultsFound:
+        except exc.MultipleResultsFound:
             raise exception.Conflict(
-                'Multiple audit templates exist with same name.'
-                ' Please use the audit template uuid instead.')
-        except NoResultFound:
+                _('Multiple audit templates exist with the same name.'
+                  ' Please use the audit template uuid instead'))
+        except exc.NoResultFound:
             raise exception.AuditTemplateNotFound(
                 audit_template=audit_template_name)
 
@@ -268,7 +267,7 @@ class Connection(api.BaseConnection):
 
             try:
                 query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditTemplateNotFound(node=audit_template_id)
 
             query.delete()
@@ -287,7 +286,7 @@ class Connection(api.BaseConnection):
             query = add_identity_filter(query, audit_template_id)
             try:
                 ref = query.with_lockmode('update').one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditTemplateNotFound(
                     audit_template=audit_template_id)
 
@@ -302,7 +301,7 @@ class Connection(api.BaseConnection):
 
             try:
                 query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditTemplateNotFound(node=audit_template_id)
 
             query.soft_delete()
@@ -323,7 +322,7 @@ class Connection(api.BaseConnection):
             values['uuid'] = utils.generate_uuid()
 
         if values.get('state') is None:
-            values['state'] = AuditStatus.PENDING
+            values['state'] = audit_objects.AuditStatus.PENDING
 
         audit = models.Audit()
         audit.update(values)
@@ -343,7 +342,7 @@ class Connection(api.BaseConnection):
                 if audit.state == 'DELETED':
                     raise exception.AuditNotFound(audit=audit_id)
             return audit
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.AuditNotFound(audit=audit_id)
 
     def get_audit_by_uuid(self, context, audit_uuid):
@@ -356,7 +355,7 @@ class Connection(api.BaseConnection):
                 if audit.state == 'DELETED':
                     raise exception.AuditNotFound(audit=audit_uuid)
             return audit
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.AuditNotFound(audit=audit_uuid)
 
     def destroy_audit(self, audit_id):
@@ -374,7 +373,7 @@ class Connection(api.BaseConnection):
 
             try:
                 audit_ref = query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditNotFound(audit=audit_id)
 
             if is_audit_referenced(session, audit_ref['id']):
@@ -396,7 +395,7 @@ class Connection(api.BaseConnection):
             query = add_identity_filter(query, audit_id)
             try:
                 ref = query.with_lockmode('update').one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditNotFound(audit=audit_id)
 
             ref.update(values)
@@ -410,7 +409,7 @@ class Connection(api.BaseConnection):
 
             try:
                 query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.AuditNotFound(node=audit_id)
 
             query.soft_delete()
@@ -447,7 +446,7 @@ class Connection(api.BaseConnection):
                     raise exception.ActionNotFound(
                         action=action_id)
             return action
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.ActionNotFound(action=action_id)
 
     def get_action_by_uuid(self, context, action_uuid):
@@ -460,7 +459,7 @@ class Connection(api.BaseConnection):
                     raise exception.ActionNotFound(
                         action=action_uuid)
             return action
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.ActionNotFound(action=action_uuid)
 
     def destroy_action(self, action_id):
@@ -487,7 +486,7 @@ class Connection(api.BaseConnection):
             query = add_identity_filter(query, action_id)
             try:
                 ref = query.with_lockmode('update').one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.ActionNotFound(action=action_id)
 
             ref.update(values)
@@ -501,7 +500,7 @@ class Connection(api.BaseConnection):
 
             try:
                 query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.ActionNotFound(node=action_id)
 
             query.soft_delete()
@@ -541,7 +540,7 @@ class Connection(api.BaseConnection):
                     raise exception.ActionPlanNotFound(
                         action_plan=action_plan_id)
             return action_plan
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.ActionPlanNotFound(action_plan=action_plan_id)
 
     def get_action_plan_by_uuid(self, context, action_plan__uuid):
@@ -555,7 +554,7 @@ class Connection(api.BaseConnection):
                     raise exception.ActionPlanNotFound(
                         action_plan=action_plan__uuid)
             return action_plan
-        except NoResultFound:
+        except exc.NoResultFound:
             raise exception.ActionPlanNotFound(action_plan=action_plan__uuid)
 
     def destroy_action_plan(self, action_plan_id):
@@ -573,7 +572,7 @@ class Connection(api.BaseConnection):
 
             try:
                 action_plan_ref = query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.ActionPlanNotFound(action_plan=action_plan_id)
 
             if is_action_plan_referenced(session, action_plan_ref['id']):
@@ -596,7 +595,7 @@ class Connection(api.BaseConnection):
             query = add_identity_filter(query, action_plan_id)
             try:
                 ref = query.with_lockmode('update').one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.ActionPlanNotFound(action_plan=action_plan_id)
 
             ref.update(values)
@@ -610,7 +609,7 @@ class Connection(api.BaseConnection):
 
             try:
                 query.one()
-            except NoResultFound:
+            except exc.NoResultFound:
                 raise exception.ActionPlanNotFound(node=action_plan_id)
 
             query.soft_delete()
diff --git a/watcher/db/sqlalchemy/migration.py b/watcher/db/sqlalchemy/migration.py
index a52f21c12..6cd020af6 100644
--- a/watcher/db/sqlalchemy/migration.py
+++ b/watcher/db/sqlalchemy/migration.py
@@ -21,6 +21,7 @@ from alembic import config as alembic_config
 import alembic.migration as alembic_migration
 from oslo_db import exception as db_exc
 
+from watcher._i18n import _
 from watcher.db.sqlalchemy import api as sqla_api
 from watcher.db.sqlalchemy import models
 
@@ -68,8 +69,9 @@ def create_schema(config=None, engine=None):
     #                schema, it will only add the new tables, but leave
     #                existing as is. So we should avoid of this situation.
     if version(engine=engine) is not None:
-        raise db_exc.DbMigrationError("DB schema is already under version"
-                                      " control. Use upgrade() instead")
+        raise db_exc.DbMigrationError(
+            _("Watcher database schema is already under version control; "
+              "use upgrade() instead"))
 
     models.Base.metadata.create_all(engine)
     stamp('head', config=config)
diff --git a/watcher/decision_engine/model/model_root.py b/watcher/decision_engine/model/model_root.py
index 9f09a998c..f9aaa49e8 100644
--- a/watcher/decision_engine/model/model_root.py
+++ b/watcher/decision_engine/model/model_root.py
@@ -15,12 +15,11 @@
 # limitations under the License.
 from oslo_log import log
 
-from watcher.common.exception import HypervisorNotFound
-from watcher.common.exception import IllegalArgumentException
-from watcher.common.exception import VMNotFound
-from watcher.decision_engine.model.hypervisor import Hypervisor
-from watcher.decision_engine.model.mapping import Mapping
-from watcher.decision_engine.model.vm import VM
+from watcher._i18n import _
+from watcher.common import exception
+from watcher.decision_engine.model import hypervisor
+from watcher.decision_engine.model import mapping
+from watcher.decision_engine.model import vm
 
 LOG = log.getLogger(__name__)
 
@@ -29,18 +28,18 @@ class ModelRoot(object):
     def __init__(self):
         self._hypervisors = {}
         self._vms = {}
-        self.mapping = Mapping(self)
+        self.mapping = mapping.Mapping(self)
         self.resource = {}
 
-    def assert_hypervisor(self, hypervisor):
-        if not isinstance(hypervisor, Hypervisor):
-            raise IllegalArgumentException(
-                "Hypervisor must be an instance of hypervisor")
+    def assert_hypervisor(self, obj):
+        if not isinstance(obj, hypervisor.Hypervisor):
+            raise exception.IllegalArgumentException(
+                _("'obj' argument type is not valid"))
 
-    def assert_vm(self, vm):
-        if not isinstance(vm, VM):
-            raise IllegalArgumentException(
-                "VM must be an instance of VM")
+    def assert_vm(self, obj):
+        if not isinstance(obj, vm.VM):
+            raise exception.IllegalArgumentException(
+                _("'obj' argument type is not valid"))
 
     def add_hypervisor(self, hypervisor):
         self.assert_hypervisor(hypervisor)
@@ -49,7 +48,7 @@ class ModelRoot(object):
     def remove_hypervisor(self, hypervisor):
         self.assert_hypervisor(hypervisor)
         if str(hypervisor.uuid) not in self._hypervisors.keys():
-            raise HypervisorNotFound(hypervisor.uuid)
+            raise exception.HypervisorNotFound(hypervisor.uuid)
         else:
             del self._hypervisors[hypervisor.uuid]
 
@@ -62,12 +61,12 @@ class ModelRoot(object):
 
     def get_hypervisor_from_id(self, hypervisor_uuid):
         if str(hypervisor_uuid) not in self._hypervisors.keys():
-            raise HypervisorNotFound(hypervisor_uuid)
+            raise exception.HypervisorNotFound(hypervisor_uuid)
         return self._hypervisors[str(hypervisor_uuid)]
 
     def get_vm_from_id(self, uuid):
         if str(uuid) not in self._vms.keys():
-            raise VMNotFound(uuid)
+            raise exception.VMNotFound(uuid)
         return self._vms[str(uuid)]
 
     def get_all_vms(self):
diff --git a/watcher/decision_engine/planner/default.py b/watcher/decision_engine/planner/default.py
index 3c7b043ee..6262b29e9 100644
--- a/watcher/decision_engine/planner/default.py
+++ b/watcher/decision_engine/planner/default.py
@@ -19,20 +19,17 @@
 from oslo_log import log
 
 from enum import Enum
-from watcher.common.exception import MetaActionNotFound
+
+from watcher._i18n import _LW
+from watcher.common import exception
 from watcher.common import utils
-from watcher.decision_engine.planner.base import BasePlanner
-
+from watcher.decision_engine.actions import hypervisor_state
+from watcher.decision_engine.actions import migration
+from watcher.decision_engine.actions import nop
+from watcher.decision_engine.actions import power_state
+from watcher.decision_engine.planner import base
 from watcher import objects
 
-from watcher.decision_engine.actions.hypervisor_state import \
-    ChangeHypervisorState
-from watcher.decision_engine.actions.migration import Migrate
-from watcher.decision_engine.actions.nop import Nop
-from watcher.decision_engine.actions.power_state import ChangePowerState
-from watcher.objects.action import Status as AStatus
-from watcher.objects.action_plan import Status as APStatus
-
 LOG = log.getLogger(__name__)
 
 
@@ -57,7 +54,7 @@ priority_primitives = {
 }
 
 
-class DefaultPlanner(BasePlanner):
+class DefaultPlanner(base.BasePlanner):
     def create_action(self, action_plan_id, action_type, applies_to=None,
                       src=None,
                       dst=None,
@@ -74,7 +71,7 @@ class DefaultPlanner(BasePlanner):
             'dst': dst,
             'parameter': parameter,
             'description': description,
-            'state': AStatus.PENDING,
+            'state': objects.action.Status.PENDING,
             'alarm': None,
             'next': None,
         }
@@ -88,7 +85,7 @@ class DefaultPlanner(BasePlanner):
         to_schedule = []
 
         for action in actions:
-            if isinstance(action, Migrate):
+            if isinstance(action, migration.Migrate):
                 # TODO(jed) type
                 primitive = self.create_action(action_plan.id,
                                                Primitives.LIVE_MIGRATE.value,
@@ -101,7 +98,7 @@ class DefaultPlanner(BasePlanner):
                                                    action)
                                                )
 
-            elif isinstance(action, ChangePowerState):
+            elif isinstance(action, power_state.ChangePowerState):
                 primitive = self.create_action(action_plan_id=action_plan.id,
                                                action_type=Primitives.
                                                POWER_STATE.value,
@@ -111,7 +108,7 @@ class DefaultPlanner(BasePlanner):
                                                value,
                                                description="{0}".format(
                                                    action))
-            elif isinstance(action, ChangeHypervisorState):
+            elif isinstance(action, hypervisor_state.ChangeHypervisorState):
                 primitive = self.create_action(action_plan_id=action_plan.id,
                                                action_type=Primitives.
                                                HYPERVISOR_STATE.value,
@@ -120,21 +117,21 @@ class DefaultPlanner(BasePlanner):
                                                value,
                                                description="{0}".format(
                                                    action))
-            elif isinstance(action, Nop):
+            elif isinstance(action, nop.Nop):
                 primitive = self.create_action(action_plan_id=action_plan.id,
                                                action_type=Primitives.
                                                NOP.value,
                                                description="{0}".format(
                                                    action))
             else:
-                raise MetaActionNotFound()
+                raise exception.MetaActionNotFound()
             priority = priority_primitives[primitive['action_type']]
             to_schedule.append((priority, primitive))
 
         # scheduling
         scheduled = sorted(to_schedule, reverse=False, key=lambda x: (x[0]))
         if len(scheduled) == 0:
-            LOG.warning("The ActionPlan is empty")
+            LOG.warning(_LW("The action plan is empty"))
             action_plan.first_action_id = None
             action_plan.save()
         else:
@@ -157,7 +154,7 @@ class DefaultPlanner(BasePlanner):
             'uuid': utils.generate_uuid(),
             'audit_id': audit_id,
             'first_action_id': None,
-            'state': APStatus.RECOMMENDED
+            'state': objects.action_plan.Status.RECOMMENDED
         }
 
         new_action_plan = objects.ActionPlan(context, **action_plan_dict)
diff --git a/watcher/decision_engine/rpcapi.py b/watcher/decision_engine/rpcapi.py
index c51e96304..d40731992 100644
--- a/watcher/decision_engine/rpcapi.py
+++ b/watcher/decision_engine/rpcapi.py
@@ -28,7 +28,6 @@ from watcher.common import utils
 from watcher.decision_engine.event.consumer_factory import EventConsumerFactory
 from watcher.decision_engine.manager import decision_engine_opt_group
 from watcher.decision_engine.manager import WATCHER_DECISION_ENGINE_OPTS
-
 from watcher.decision_engine.messaging.events import Events
 
 LOG = log.getLogger(__name__)
@@ -82,5 +81,5 @@ class DecisionEngineAPI(MessagingCore):
             event_consumer = EventConsumerFactory.factory(event_type)
             event_consumer.execute(request_id, self.context, data)
         except Exception as e:
-            LOG.error("evt %s" % e.message)
-            raise e
+            LOG.exception(e)
+            raise
diff --git a/watcher/decision_engine/strategy/selection/default.py b/watcher/decision_engine/strategy/selection/default.py
index 9a0a5abad..7462288c5 100644
--- a/watcher/decision_engine/strategy/selection/default.py
+++ b/watcher/decision_engine/strategy/selection/default.py
@@ -17,10 +17,10 @@
 from oslo_config import cfg
 from oslo_log import log
 
-from watcher.common.exception import WatcherException
-from watcher.decision_engine.strategy.loading.default import \
-    DefaultStrategyLoader
-from watcher.decision_engine.strategy.selection.base import BaseSelector
+from watcher._i18n import _
+from watcher.common import exception
+from watcher.decision_engine.strategy.loading import default
+from watcher.decision_engine.strategy.selection import base
 
 LOG = log.getLogger(__name__)
 CONF = cfg.CONF
@@ -41,11 +41,11 @@ CONF.register_group(goals_opt_group)
 CONF.register_opts(WATCHER_GOALS_OPTS, goals_opt_group)
 
 
-class DefaultStrategySelector(BaseSelector):
+class DefaultStrategySelector(base.BaseSelector):
 
     def __init__(self):
         super(DefaultStrategySelector, self).__init__()
-        self.strategy_loader = DefaultStrategyLoader()
+        self.strategy_loader = default.DefaultStrategyLoader()
 
     def define_from_goal(self, goal_name):
         strategy_to_load = None
@@ -54,7 +54,7 @@ class DefaultStrategySelector(BaseSelector):
             return self.strategy_loader.load(strategy_to_load)
         except KeyError as exc:
             LOG.exception(exc)
-            raise WatcherException(
-                "Incorrect mapping: could not find "
-                "associated strategy for '%s'" % goal_name
+            raise exception.WatcherException(
+                _("Incorrect mapping: could not find "
+                  "associated strategy for '%s'") % goal_name
             )
diff --git a/watcher/decision_engine/strategy/strategies/basic_consolidation.py b/watcher/decision_engine/strategy/strategies/basic_consolidation.py
index 4e268baca..59d04ee1d 100644
--- a/watcher/decision_engine/strategy/strategies/basic_consolidation.py
+++ b/watcher/decision_engine/strategy/strategies/basic_consolidation.py
@@ -16,7 +16,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+
 from oslo_log import log
+
+from watcher._i18n import _LE, _LI, _LW
 from watcher.common.exception import ClusterEmpty
 from watcher.common.exception import ClusterStateNotDefined
 from watcher.decision_engine.actions.hypervisor_state import \
@@ -40,6 +43,9 @@ class BasicConsolidation(BaseStrategy):
     DEFAULT_NAME = "basic"
     DEFAULT_DESCRIPTION = "Basic offline consolidation"
 
+    host_cpu_usage_metric_name = 'compute.node.cpu.percent'
+    instance_cpu_usage_metric_name = 'cpu_util'
+
     def __init__(self, name=DEFAULT_NAME, description=DEFAULT_DESCRIPTION):
         """Basic offline Consolidation using live migration
 
@@ -254,18 +260,20 @@ class BasicConsolidation(BaseStrategy):
             :param model:
             :return:
             """
-        resource_id = "{0}_{1}".format(hypervisor.uuid,
-                                       hypervisor.hostname)
+        resource_id = "%s_%s" % (hypervisor.uuid, hypervisor.hostname)
         cpu_avg_vm = self.ceilometer. \
             statistic_aggregation(resource_id=resource_id,
-                                  meter_name='compute.node.cpu.percent',
+                                  meter_name=self.host_cpu_usage_metric_name,
                                   period="7200",
                                   aggregate='avg'
                                   )
         if cpu_avg_vm is None:
             LOG.error(
-                "No values returned for {0} compute.node.cpu.percent".format(
-                    resource_id))
+                _LE("No values returned by %(resource_id)s "
+                    "for %(metric_name)s"),
+                resource_id=resource_id,
+                metric_name=self.host_cpu_usage_metric_name,
+            )
             cpu_avg_vm = 100
 
         cpu_capacity = model.get_resource_from_id(
@@ -300,14 +308,19 @@ class BasicConsolidation(BaseStrategy):
             raise ClusterStateNotDefined()
 
         vm_cpu_utilization = self.ceilometer. \
-            statistic_aggregation(resource_id=vm.uuid,
-                                  meter_name='cpu_util',
-                                  period="7200",
-                                  aggregate='avg'
-                                  )
+            statistic_aggregation(
+                resource_id=vm.uuid,
+                meter_name=self.instance_cpu_usage_metric_name,
+                period="7200",
+                aggregate='avg'
+            )
         if vm_cpu_utilization is None:
             LOG.error(
-                "No values returned for {0} cpu_util".format(vm.uuid))
+                _LE("No values returned by %(resource_id)s "
+                    "for %(metric_name)s"),
+                resource_id=vm.uuid,
+                metric_name=self.instance_cpu_usage_metric_name,
+            )
             vm_cpu_utilization = 100
 
         cpu_capacity = model.get_resource_from_id(
@@ -331,7 +344,7 @@ class BasicConsolidation(BaseStrategy):
                                  model)))
 
     def execute(self, orign_model):
-        LOG.debug("Initialize Sercon Consolidation")
+        LOG.info(_LI("Initializing Sercon Consolidation"))
 
         if orign_model is None:
             raise ClusterStateNotDefined()
@@ -393,9 +406,9 @@ class BasicConsolidation(BaseStrategy):
 
             ''' get Node to be released '''
             if len(score) == 0:
-                LOG.warning(
+                LOG.warning(_LW(
                     "The workloads of the compute nodes"
-                    " of the cluster is zero.")
+                    " of the cluster is zero"))
                 break
 
             node_to_release = s[len(score) - 1][0]
@@ -413,6 +426,7 @@ class BasicConsolidation(BaseStrategy):
 
             ''' sort VMs by Score '''
             v = sorted(vm_score, reverse=True, key=lambda x: (x[1]))
+            # BFD: Best Fit Decrease
             LOG.debug("VM(s) BFD {0}".format(v))
 
             m = 0
diff --git a/watcher/locale/fr/LC_MESSAGES/messages.po b/watcher/locale/fr/LC_MESSAGES/messages.po
deleted file mode 100644
index 8c871e377..000000000
--- a/watcher/locale/fr/LC_MESSAGES/messages.po
+++ /dev/null
@@ -1,285 +0,0 @@
-# French translations for python-watcher.
-# Copyright (C) 2015 ORGANIZATION
-# This file is distributed under the same license as the python-watcher
-# project.
-# FIRST AUTHOR <EMAIL@ADDRESS>, 2015.
-#
-#, fuzzy
-msgid ""
-msgstr ""
-"Project-Id-Version: python-watcher 0.21.1.dev32\n"
-"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2015-12-11 15:29+0100\n"
-"PO-Revision-Date: 2015-12-11 15:42+0100\n"
-"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
-"Language: fr\n"
-"Language-Team: fr <LL@li.org>\n"
-"Plural-Forms: nplurals=2; plural=(n > 1)\n"
-"MIME-Version: 1.0\n"
-"Content-Type: text/plain; charset=utf-8\n"
-"Content-Transfer-Encoding: 8bit\n"
-"Generated-By: Babel 2.1.1\n"
-
-#: watcher/api/controllers/v1/types.py:148
-#, python-format
-msgid "%s is not JSON serializable"
-msgstr ""
-
-#: watcher/api/controllers/v1/types.py:184
-#, python-format
-msgid "Wrong type. Expected '%(type)s', got '%(value)s'"
-msgstr ""
-
-#: watcher/api/controllers/v1/types.py:222
-#, python-format
-msgid "'%s' is an internal attribute and can not be updated"
-msgstr ""
-
-#: watcher/api/controllers/v1/types.py:226
-#, python-format
-msgid "'%s' is a mandatory attribute and can not be removed"
-msgstr ""
-
-#: watcher/api/controllers/v1/types.py:231
-msgid "'add' and 'replace' operations needs value"
-msgstr ""
-
-#: watcher/api/controllers/v1/utils.py:32
-msgid "Limit must be positive"
-msgstr ""
-
-#: watcher/api/controllers/v1/utils.py:39
-#, python-format
-msgid "Invalid sort direction: %s. Acceptable values are 'asc' or 'desc'"
-msgstr ""
-
-#: watcher/api/controllers/v1/utils.py:49
-#, python-format
-msgid "Adding a new attribute (%s) to the root of  the resource is not allowed"
-msgstr ""
-
-#: watcher/api/middleware/auth_token.py:43
-#, python-format
-msgid "Cannot compile public API routes: %s"
-msgstr ""
-
-#: watcher/api/middleware/parsable_error.py:53
-#, python-format
-msgid "ErrorDocumentMiddleware received an invalid status %s"
-msgstr ""
-
-#: watcher/cmd/api.py:45
-#, python-format
-msgid "Starting server in PID %s"
-msgstr ""
-
-#: watcher/cmd/api.py:50
-#, python-format
-msgid "serving on 0.0.0.0:%(port)s, view at http://127.0.0.1:%(port)s"
-msgstr ""
-
-#: watcher/cmd/api.py:54
-#, python-format
-msgid "serving on http://%(host)s:%(port)s"
-msgstr ""
-
-#: watcher/common/exception.py:58
-msgid "An unknown exception occurred."
-msgstr ""
-
-#: watcher/common/exception.py:109
-msgid "Not authorized."
-msgstr ""
-
-#: watcher/common/exception.py:114
-msgid "Operation not permitted."
-msgstr ""
-
-#: watcher/common/exception.py:118
-msgid "Unacceptable parameters."
-msgstr ""
-
-#: watcher/common/exception.py:123
-#, python-format
-msgid "The %(name)s %(id)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:127
-msgid "Conflict."
-msgstr ""
-
-#: watcher/common/exception.py:132
-#, python-format
-msgid "The %(name)s resource %(id)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:137
-#, python-format
-msgid "Expected an uuid or int but received %(identity)s."
-msgstr ""
-
-#: watcher/common/exception.py:141
-#, python-format
-msgid "Goal %(goal)s is not defined in Watcher configuration file."
-msgstr ""
-
-#: watcher/common/exception.py:147
-#, python-format
-msgid "%(err)s"
-msgstr ""
-
-#: watcher/common/exception.py:151
-#, python-format
-msgid "Expected a uuid but received %(uuid)s."
-msgstr ""
-
-#: watcher/common/exception.py:155
-#, python-format
-msgid "Expected a logical name but received %(name)s."
-msgstr ""
-
-#: watcher/common/exception.py:159
-#, python-format
-msgid "Expected a logical name or uuid but received %(name)s."
-msgstr ""
-
-#: watcher/common/exception.py:163
-#, python-format
-msgid "AuditTemplate %(audit_template)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:167
-#, python-format
-msgid "An audit_template with UUID %(uuid)s or name %(name)s already exists."
-msgstr ""
-
-#: watcher/common/exception.py:172
-#, python-format
-msgid "AuditTemplate %(audit_template)s is referenced by one or multiple audit."
-msgstr ""
-
-#: watcher/common/exception.py:177
-#, python-format
-msgid "Audit %(audit)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:181
-#, python-format
-msgid "An audit with UUID %(uuid)s already exists."
-msgstr ""
-
-#: watcher/common/exception.py:185
-#, python-format
-msgid "Audit %(audit)s is referenced by one or multiple action plans."
-msgstr ""
-
-#: watcher/common/exception.py:190
-msgid "ActionPlan %(action plan)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:194
-#, python-format
-msgid "An action plan with UUID %(uuid)s already exists."
-msgstr ""
-
-#: watcher/common/exception.py:198
-#, python-format
-msgid "Action Plan %(action_plan)s is referenced by one or multiple actions."
-msgstr ""
-
-#: watcher/common/exception.py:203
-#, python-format
-msgid "Action %(action)s could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:207
-#, python-format
-msgid "An action with UUID %(uuid)s already exists."
-msgstr ""
-
-#: watcher/common/exception.py:211
-#, python-format
-msgid "Action plan %(action_plan)s is referenced by one or multiple goals."
-msgstr ""
-
-#: watcher/common/exception.py:216
-msgid "Filtering actions on both audit and action-plan is prohibited."
-msgstr ""
-
-#: watcher/common/exception.py:225
-#, python-format
-msgid "Couldn't apply patch '%(patch)s'. Reason: %(reason)s"
-msgstr ""
-
-#: watcher/common/exception.py:286
-msgid "'Keystone API endpoint is missing''"
-msgstr ""
-
-#: watcher/common/exception.py:290
-msgid "The list of hypervisor(s) in the cluster is empty.'"
-msgstr ""
-
-#: watcher/common/exception.py:294
-msgid "The metrics resource collector is not defined.'"
-msgstr ""
-
-#: watcher/common/exception.py:298
-msgid "the cluster state is not defined"
-msgstr ""
-
-#: watcher/common/exception.py:304
-msgid "The VM could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:308
-msgid "The hypervisor could not be found."
-msgstr ""
-
-#: watcher/common/exception.py:312
-msgid "The Meta-Action could not be found."
-msgstr ""
-
-#: watcher/db/sqlalchemy/api.py:278
-msgid "Cannot overwrite UUID for an existing AuditTemplate."
-msgstr ""
-
-#: watcher/db/sqlalchemy/api.py:387 watcher/db/sqlalchemy/api.py:587
-msgid "Cannot overwrite UUID for an existing Audit."
-msgstr ""
-
-#: watcher/db/sqlalchemy/api.py:478
-msgid "Cannot overwrite UUID for an existing Action."
-msgstr ""
-
-#: watcher/objects/base.py:108
-msgid "Invalid version string"
-msgstr ""
-
-#: watcher/objects/base.py:299
-#, python-format
-msgid "Cannot load '%(attrname)s' in the base class"
-msgstr ""
-
-#: watcher/objects/base.py:308
-msgid "Cannot save anything in the base class"
-msgstr ""
-
-#: watcher/objects/base.py:340
-#, python-format
-msgid "%(objname)s object has no attribute '%(attrname)s'"
-msgstr ""
-
-#: watcher/objects/base.py:389
-#, python-format
-msgid "'%(objclass)s' object has no attribute '%(attrname)s'"
-msgstr ""
-
-#: watcher/objects/utils.py:40
-msgid "A datetime.datetime is required here"
-msgstr ""
-
-#: watcher/objects/utils.py:105
-#, python-format
-msgid "An object of class %s is required here"
-msgstr ""
-
diff --git a/watcher/locale/fr/LC_MESSAGES/watcher.po b/watcher/locale/fr/LC_MESSAGES/watcher.po
new file mode 100644
index 000000000..ce996004e
--- /dev/null
+++ b/watcher/locale/fr/LC_MESSAGES/watcher.po
@@ -0,0 +1,436 @@
+# French translations for python-watcher.
+# Copyright (C) 2015 ORGANIZATION
+# This file is distributed under the same license as the python-watcher
+# project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2015.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: python-watcher 0.21.1.dev32\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2015-12-18 15:33+0100\n"
+"PO-Revision-Date: 2015-12-11 15:42+0100\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language: fr\n"
+"Language-Team: fr <LL@li.org>\n"
+"Plural-Forms: nplurals=2; plural=(n > 1)\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 2.1.1\n"
+
+#: watcher/api/controllers/v1/types.py:148
+#, python-format
+msgid "%s is not JSON serializable"
+msgstr ""
+
+#: watcher/api/controllers/v1/types.py:184
+#, python-format
+msgid "Wrong type. Expected '%(type)s', got '%(value)s'"
+msgstr ""
+
+#: watcher/api/controllers/v1/types.py:223
+#, python-format
+msgid "'%s' is an internal attribute and can not be updated"
+msgstr ""
+
+#: watcher/api/controllers/v1/types.py:227
+#, python-format
+msgid "'%s' is a mandatory attribute and can not be removed"
+msgstr "'%s' est un attribut obligatoire et ne peut pas être enlevé"
+
+#: watcher/api/controllers/v1/types.py:232
+msgid "'add' and 'replace' operations needs value"
+msgstr "Les opérations 'add' et 'replace' recquièrent une valeur"
+
+#: watcher/api/controllers/v1/utils.py:36
+msgid "Limit must be positive"
+msgstr "Limit doit être positif"
+
+#: watcher/api/controllers/v1/utils.py:47
+#, python-format
+msgid "Invalid sort direction: %s. Acceptable values are 'asc' or 'desc'"
+msgstr ""
+
+#: watcher/api/controllers/v1/utils.py:57
+#, python-format
+msgid "Adding a new attribute (%s) to the root of  the resource is not allowed"
+msgstr ""
+
+#: watcher/api/middleware/auth_token.py:45
+msgid "Cannot compile public API routes"
+msgstr ""
+
+#: watcher/api/middleware/parsable_error.py:52
+#, python-format
+msgid "ErrorDocumentMiddleware received an invalid status %s"
+msgstr ""
+
+#: watcher/applier/primitives/change_nova_service_state.py:74
+msgid "The target state is not defined"
+msgstr ""
+
+#: watcher/cmd/api.py:46
+#, python-format
+msgid "Starting server in PID %s"
+msgstr "Démarre le serveur avec pour PID %s"
+
+#: watcher/cmd/api.py:51
+#, python-format
+msgid "serving on 0.0.0.0:%(port)s, view at http://127.0.0.1:%(port)s"
+msgstr "Sert sur 0.0.0.0:%(port)s, accessible à http://127.0.0.1:%(port)s"
+
+#: watcher/cmd/api.py:55
+#, python-format
+msgid "serving on http://%(host)s:%(port)s"
+msgstr "Sert sur http://%(host)s:%(port)s"
+
+#: watcher/common/exception.py:56
+msgid "An unknown exception occurred"
+msgstr ""
+
+#: watcher/common/exception.py:107
+msgid "Not authorized"
+msgstr ""
+
+#: watcher/common/exception.py:112
+msgid "Operation not permitted"
+msgstr ""
+
+#: watcher/common/exception.py:116
+msgid "Unacceptable parameters"
+msgstr ""
+
+#: watcher/common/exception.py:121
+#, python-format
+msgid "The %(name)s %(id)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:125
+#, fuzzy
+msgid "Conflict"
+msgstr "Conflit."
+
+#: watcher/common/exception.py:130
+#, python-format
+msgid "The %(name)s resource %(id)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:135
+#, python-format
+msgid "Expected an uuid or int but received %(identity)s"
+msgstr ""
+
+#: watcher/common/exception.py:139
+#, python-format
+msgid "Goal %(goal)s is not defined in Watcher configuration file"
+msgstr ""
+
+#: watcher/common/exception.py:145
+#, python-format
+msgid "%(err)s"
+msgstr ""
+
+#: watcher/common/exception.py:149
+#, python-format
+msgid "Expected a uuid but received %(uuid)s"
+msgstr ""
+
+#: watcher/common/exception.py:153
+#, python-format
+msgid "Expected a logical name but received %(name)s"
+msgstr ""
+
+#: watcher/common/exception.py:157
+#, python-format
+msgid "Expected a logical name or uuid but received %(name)s"
+msgstr ""
+
+#: watcher/common/exception.py:161
+#, python-format
+msgid "AuditTemplate %(audit_template)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:165
+#, python-format
+msgid "An audit_template with UUID %(uuid)s or name %(name)s already exists"
+msgstr ""
+
+#: watcher/common/exception.py:170
+#, python-format
+msgid "AuditTemplate %(audit_template)s is referenced by one or multiple audit"
+msgstr ""
+
+#: watcher/common/exception.py:175
+#, python-format
+msgid "Audit %(audit)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:179
+#, python-format
+msgid "An audit with UUID %(uuid)s already exists"
+msgstr ""
+
+#: watcher/common/exception.py:183
+#, python-format
+msgid "Audit %(audit)s is referenced by one or multiple action plans"
+msgstr ""
+
+#: watcher/common/exception.py:188
+msgid "ActionPlan %(action plan)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:192
+#, python-format
+msgid "An action plan with UUID %(uuid)s already exists"
+msgstr ""
+
+#: watcher/common/exception.py:196
+#, python-format
+msgid "Action Plan %(action_plan)s is referenced by one or multiple actions"
+msgstr ""
+
+#: watcher/common/exception.py:201
+#, python-format
+msgid "Action %(action)s could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:205
+#, python-format
+msgid "An action with UUID %(uuid)s already exists"
+msgstr ""
+
+#: watcher/common/exception.py:209
+#, python-format
+msgid "Action plan %(action_plan)s is referenced by one or multiple goals"
+msgstr ""
+
+#: watcher/common/exception.py:214
+msgid "Filtering actions on both audit and action-plan is prohibited"
+msgstr ""
+
+#: watcher/common/exception.py:223
+#, python-format
+msgid "Couldn't apply patch '%(patch)s'. Reason: %(reason)s"
+msgstr ""
+
+#: watcher/common/exception.py:233
+msgid "Description must be an instance of str"
+msgstr ""
+
+#: watcher/common/exception.py:243
+msgid "An exception occurred without a description"
+msgstr ""
+
+#: watcher/common/exception.py:251
+msgid "Description cannot be empty"
+msgstr ""
+
+#: watcher/common/exception.py:260
+msgid "No such metric"
+msgstr ""
+
+#: watcher/common/exception.py:269
+msgid "No rows were returned"
+msgstr ""
+
+#: watcher/common/exception.py:277
+msgid "'Keystone API endpoint is missing''"
+msgstr ""
+
+#: watcher/common/exception.py:281
+msgid "The list of hypervisor(s) in the cluster is empty"
+msgstr ""
+
+#: watcher/common/exception.py:285
+msgid "The metrics resource collector is not defined"
+msgstr ""
+
+#: watcher/common/exception.py:289
+msgid "the cluster state is not defined"
+msgstr ""
+
+#: watcher/common/exception.py:295
+msgid "The VM could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:299
+msgid "The hypervisor could not be found"
+msgstr ""
+
+#: watcher/common/exception.py:303
+msgid "The Meta-Action could not be found"
+msgstr ""
+
+#: watcher/common/keystone.py:59
+msgid "No Keystone service catalog loaded"
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:256
+msgid ""
+"Multiple audit templates exist with the same name. Please use the audit "
+"template uuid instead"
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:277
+msgid "Cannot overwrite UUID for an existing AuditTemplate."
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:386 watcher/db/sqlalchemy/api.py:586
+msgid "Cannot overwrite UUID for an existing Audit."
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:477
+msgid "Cannot overwrite UUID for an existing Action."
+msgstr ""
+
+#: watcher/db/sqlalchemy/migration.py:73
+msgid ""
+"Watcher database schema is already under version control; use upgrade() "
+"instead"
+msgstr ""
+
+#: watcher/decision_engine/model/model_root.py:37
+#: watcher/decision_engine/model/model_root.py:42
+msgid "'obj' argument type is not valid"
+msgstr ""
+
+#: watcher/decision_engine/strategy/selection/default.py:56
+#, python-format
+msgid "Incorrect mapping: could not find associated strategy for '%s'"
+msgstr ""
+
+#: watcher/objects/base.py:108
+msgid "Invalid version string"
+msgstr ""
+
+#: watcher/objects/base.py:299
+#, python-format
+msgid "Cannot load '%(attrname)s' in the base class"
+msgstr ""
+
+#: watcher/objects/base.py:308
+msgid "Cannot save anything in the base class"
+msgstr ""
+
+#: watcher/objects/base.py:340
+#, python-format
+msgid "%(objname)s object has no attribute '%(attrname)s'"
+msgstr ""
+
+#: watcher/objects/base.py:390
+#, python-format
+msgid "'%(objclass)s' object has no attribute '%(attrname)s'"
+msgstr ""
+
+#: watcher/objects/utils.py:40
+msgid "A datetime.datetime is required here"
+msgstr ""
+
+#: watcher/objects/utils.py:105
+#, python-format
+msgid "An object of class %s is required here"
+msgstr ""
+
+#~ msgid "Cannot compile public API routes: %s"
+#~ msgstr ""
+
+#~ msgid "An exception occurred without a description."
+#~ msgstr ""
+
+#~ msgid "no rows were returned"
+#~ msgstr ""
+
+#~ msgid ""
+#~ msgstr ""
+
+#~ msgid "An unknown exception occurred."
+#~ msgstr ""
+
+#~ msgid "Not authorized."
+#~ msgstr ""
+
+#~ msgid "Operation not permitted."
+#~ msgstr ""
+
+#~ msgid "Unacceptable parameters."
+#~ msgstr ""
+
+#~ msgid "The %(name)s %(id)s could not be found."
+#~ msgstr ""
+
+#~ msgid "The %(name)s resource %(id)s could not be found."
+#~ msgstr ""
+
+#~ msgid "Expected an uuid or int but received %(identity)s."
+#~ msgstr ""
+
+#~ msgid "Goal %(goal)s is not defined in Watcher configuration file."
+#~ msgstr ""
+
+#~ msgid "Expected a uuid but received %(uuid)s."
+#~ msgstr ""
+
+#~ msgid "Expected a logical name but received %(name)s."
+#~ msgstr ""
+
+#~ msgid "Expected a logical name or uuid but received %(name)s."
+#~ msgstr ""
+
+#~ msgid "AuditTemplate %(audit_template)s could not be found."
+#~ msgstr ""
+
+#~ msgid "An audit_template with UUID %(uuid)s or name %(name)s already exists."
+#~ msgstr ""
+
+#~ msgid "Audit %(audit)s could not be found."
+#~ msgstr ""
+
+#~ msgid "An audit with UUID %(uuid)s already exists."
+#~ msgstr ""
+
+#~ msgid "Audit %(audit)s is referenced by one or multiple action plans."
+#~ msgstr ""
+
+#~ msgid "ActionPlan %(action plan)s could not be found."
+#~ msgstr ""
+
+#~ msgid "An action plan with UUID %(uuid)s already exists."
+#~ msgstr ""
+
+#~ msgid "Action Plan %(action_plan)s is referenced by one or multiple actions."
+#~ msgstr ""
+
+#~ msgid "Action %(action)s could not be found."
+#~ msgstr ""
+
+#~ msgid "An action with UUID %(uuid)s already exists."
+#~ msgstr ""
+
+#~ msgid "Action plan %(action_plan)s is referenced by one or multiple goals."
+#~ msgstr ""
+
+#~ msgid "Filtering actions on both audit and action-plan is prohibited."
+#~ msgstr ""
+
+#~ msgid "The list of hypervisor(s) in the cluster is empty.'"
+#~ msgstr ""
+
+#~ msgid "The metrics resource collector is not defined.'"
+#~ msgstr ""
+
+#~ msgid "The VM could not be found."
+#~ msgstr ""
+
+#~ msgid "The hypervisor could not be found."
+#~ msgstr ""
+
+#~ msgid "The Meta-Action could not be found."
+#~ msgstr ""
+
+#~ msgid "'hypervisor' argument type is not valid"
+#~ msgstr ""
+
+#~ msgid "'vm' argument type is not valid"
+#~ msgstr ""
+
diff --git a/watcher/locale/watcher.pot b/watcher/locale/watcher.pot
index 4a85bf206..2a67aa0da 100644
--- a/watcher/locale/watcher.pot
+++ b/watcher/locale/watcher.pot
@@ -7,9 +7,9 @@
 #, fuzzy
 msgid ""
 msgstr ""
-"Project-Id-Version: python-watcher 0.21.1.dev32\n"
+"Project-Id-Version: python-watcher 0.21.1.dev62\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2015-12-11 15:29+0100\n"
+"POT-Creation-Date: 2015-12-18 15:33+0100\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -28,227 +28,276 @@ msgstr ""
 msgid "Wrong type. Expected '%(type)s', got '%(value)s'"
 msgstr ""
 
-#: watcher/api/controllers/v1/types.py:222
+#: watcher/api/controllers/v1/types.py:223
 #, python-format
 msgid "'%s' is an internal attribute and can not be updated"
 msgstr ""
 
-#: watcher/api/controllers/v1/types.py:226
+#: watcher/api/controllers/v1/types.py:227
 #, python-format
 msgid "'%s' is a mandatory attribute and can not be removed"
 msgstr ""
 
-#: watcher/api/controllers/v1/types.py:231
+#: watcher/api/controllers/v1/types.py:232
 msgid "'add' and 'replace' operations needs value"
 msgstr ""
 
-#: watcher/api/controllers/v1/utils.py:32
+#: watcher/api/controllers/v1/utils.py:36
 msgid "Limit must be positive"
 msgstr ""
 
-#: watcher/api/controllers/v1/utils.py:39
+#: watcher/api/controllers/v1/utils.py:47
 #, python-format
 msgid "Invalid sort direction: %s. Acceptable values are 'asc' or 'desc'"
 msgstr ""
 
-#: watcher/api/controllers/v1/utils.py:49
+#: watcher/api/controllers/v1/utils.py:57
 #, python-format
 msgid "Adding a new attribute (%s) to the root of  the resource is not allowed"
 msgstr ""
 
-#: watcher/api/middleware/auth_token.py:43
-#, python-format
-msgid "Cannot compile public API routes: %s"
+#: watcher/api/middleware/auth_token.py:45
+msgid "Cannot compile public API routes"
 msgstr ""
 
-#: watcher/api/middleware/parsable_error.py:53
+#: watcher/api/middleware/parsable_error.py:52
 #, python-format
 msgid "ErrorDocumentMiddleware received an invalid status %s"
 msgstr ""
 
-#: watcher/cmd/api.py:45
+#: watcher/applier/primitives/change_nova_service_state.py:74
+msgid "The target state is not defined"
+msgstr ""
+
+#: watcher/cmd/api.py:46
 #, python-format
 msgid "Starting server in PID %s"
 msgstr ""
 
-#: watcher/cmd/api.py:50
+#: watcher/cmd/api.py:51
 #, python-format
 msgid "serving on 0.0.0.0:%(port)s, view at http://127.0.0.1:%(port)s"
 msgstr ""
 
-#: watcher/cmd/api.py:54
+#: watcher/cmd/api.py:55
 #, python-format
 msgid "serving on http://%(host)s:%(port)s"
 msgstr ""
 
-#: watcher/common/exception.py:58
-msgid "An unknown exception occurred."
+#: watcher/common/exception.py:56
+msgid "An unknown exception occurred"
 msgstr ""
 
-#: watcher/common/exception.py:109
-msgid "Not authorized."
+#: watcher/common/exception.py:107
+msgid "Not authorized"
 msgstr ""
 
-#: watcher/common/exception.py:114
-msgid "Operation not permitted."
+#: watcher/common/exception.py:112
+msgid "Operation not permitted"
 msgstr ""
 
-#: watcher/common/exception.py:118
-msgid "Unacceptable parameters."
+#: watcher/common/exception.py:116
+msgid "Unacceptable parameters"
 msgstr ""
 
-#: watcher/common/exception.py:123
+#: watcher/common/exception.py:121
 #, python-format
-msgid "The %(name)s %(id)s could not be found."
+msgid "The %(name)s %(id)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:127
-msgid "Conflict."
+#: watcher/common/exception.py:125
+msgid "Conflict"
 msgstr ""
 
-#: watcher/common/exception.py:132
+#: watcher/common/exception.py:130
 #, python-format
-msgid "The %(name)s resource %(id)s could not be found."
+msgid "The %(name)s resource %(id)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:137
+#: watcher/common/exception.py:135
 #, python-format
-msgid "Expected an uuid or int but received %(identity)s."
+msgid "Expected an uuid or int but received %(identity)s"
 msgstr ""
 
-#: watcher/common/exception.py:141
+#: watcher/common/exception.py:139
 #, python-format
-msgid "Goal %(goal)s is not defined in Watcher configuration file."
+msgid "Goal %(goal)s is not defined in Watcher configuration file"
 msgstr ""
 
-#: watcher/common/exception.py:147
+#: watcher/common/exception.py:145
 #, python-format
 msgid "%(err)s"
 msgstr ""
 
-#: watcher/common/exception.py:151
+#: watcher/common/exception.py:149
 #, python-format
-msgid "Expected a uuid but received %(uuid)s."
+msgid "Expected a uuid but received %(uuid)s"
 msgstr ""
 
-#: watcher/common/exception.py:155
+#: watcher/common/exception.py:153
 #, python-format
-msgid "Expected a logical name but received %(name)s."
+msgid "Expected a logical name but received %(name)s"
 msgstr ""
 
-#: watcher/common/exception.py:159
+#: watcher/common/exception.py:157
 #, python-format
-msgid "Expected a logical name or uuid but received %(name)s."
+msgid "Expected a logical name or uuid but received %(name)s"
 msgstr ""
 
-#: watcher/common/exception.py:163
+#: watcher/common/exception.py:161
 #, python-format
-msgid "AuditTemplate %(audit_template)s could not be found."
+msgid "AuditTemplate %(audit_template)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:167
+#: watcher/common/exception.py:165
 #, python-format
-msgid "An audit_template with UUID %(uuid)s or name %(name)s already exists."
+msgid "An audit_template with UUID %(uuid)s or name %(name)s already exists"
 msgstr ""
 
-#: watcher/common/exception.py:172
+#: watcher/common/exception.py:170
 #, python-format
-msgid "AuditTemplate %(audit_template)s is referenced by one or multiple audit."
+msgid "AuditTemplate %(audit_template)s is referenced by one or multiple audit"
 msgstr ""
 
-#: watcher/common/exception.py:177
+#: watcher/common/exception.py:175
 #, python-format
-msgid "Audit %(audit)s could not be found."
+msgid "Audit %(audit)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:181
+#: watcher/common/exception.py:179
 #, python-format
-msgid "An audit with UUID %(uuid)s already exists."
+msgid "An audit with UUID %(uuid)s already exists"
 msgstr ""
 
-#: watcher/common/exception.py:185
+#: watcher/common/exception.py:183
 #, python-format
-msgid "Audit %(audit)s is referenced by one or multiple action plans."
+msgid "Audit %(audit)s is referenced by one or multiple action plans"
 msgstr ""
 
-#: watcher/common/exception.py:190
-msgid "ActionPlan %(action plan)s could not be found."
+#: watcher/common/exception.py:188
+msgid "ActionPlan %(action plan)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:194
+#: watcher/common/exception.py:192
 #, python-format
-msgid "An action plan with UUID %(uuid)s already exists."
+msgid "An action plan with UUID %(uuid)s already exists"
 msgstr ""
 
-#: watcher/common/exception.py:198
+#: watcher/common/exception.py:196
 #, python-format
-msgid "Action Plan %(action_plan)s is referenced by one or multiple actions."
+msgid "Action Plan %(action_plan)s is referenced by one or multiple actions"
 msgstr ""
 
-#: watcher/common/exception.py:203
+#: watcher/common/exception.py:201
 #, python-format
-msgid "Action %(action)s could not be found."
+msgid "Action %(action)s could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:207
+#: watcher/common/exception.py:205
 #, python-format
-msgid "An action with UUID %(uuid)s already exists."
+msgid "An action with UUID %(uuid)s already exists"
 msgstr ""
 
-#: watcher/common/exception.py:211
+#: watcher/common/exception.py:209
 #, python-format
-msgid "Action plan %(action_plan)s is referenced by one or multiple goals."
+msgid "Action plan %(action_plan)s is referenced by one or multiple goals"
 msgstr ""
 
-#: watcher/common/exception.py:216
-msgid "Filtering actions on both audit and action-plan is prohibited."
+#: watcher/common/exception.py:214
+msgid "Filtering actions on both audit and action-plan is prohibited"
 msgstr ""
 
-#: watcher/common/exception.py:225
+#: watcher/common/exception.py:223
 #, python-format
 msgid "Couldn't apply patch '%(patch)s'. Reason: %(reason)s"
 msgstr ""
 
-#: watcher/common/exception.py:286
+#: watcher/common/exception.py:233
+msgid "Description must be an instance of str"
+msgstr ""
+
+#: watcher/common/exception.py:243
+msgid "An exception occurred without a description"
+msgstr ""
+
+#: watcher/common/exception.py:251
+msgid "Description cannot be empty"
+msgstr ""
+
+#: watcher/common/exception.py:260
+msgid "No such metric"
+msgstr ""
+
+#: watcher/common/exception.py:269
+msgid "No rows were returned"
+msgstr ""
+
+#: watcher/common/exception.py:277
 msgid "'Keystone API endpoint is missing''"
 msgstr ""
 
-#: watcher/common/exception.py:290
-msgid "The list of hypervisor(s) in the cluster is empty.'"
+#: watcher/common/exception.py:281
+msgid "The list of hypervisor(s) in the cluster is empty"
 msgstr ""
 
-#: watcher/common/exception.py:294
-msgid "The metrics resource collector is not defined.'"
+#: watcher/common/exception.py:285
+msgid "The metrics resource collector is not defined"
 msgstr ""
 
-#: watcher/common/exception.py:298
+#: watcher/common/exception.py:289
 msgid "the cluster state is not defined"
 msgstr ""
 
-#: watcher/common/exception.py:304
-msgid "The VM could not be found."
+#: watcher/common/exception.py:295
+msgid "The VM could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:308
-msgid "The hypervisor could not be found."
+#: watcher/common/exception.py:299
+msgid "The hypervisor could not be found"
 msgstr ""
 
-#: watcher/common/exception.py:312
-msgid "The Meta-Action could not be found."
+#: watcher/common/exception.py:303
+msgid "The Meta-Action could not be found"
 msgstr ""
 
-#: watcher/db/sqlalchemy/api.py:278
+#: watcher/common/keystone.py:59
+msgid "No Keystone service catalog loaded"
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:256
+msgid ""
+"Multiple audit templates exist with the same name. Please use the audit "
+"template uuid instead"
+msgstr ""
+
+#: watcher/db/sqlalchemy/api.py:277
 msgid "Cannot overwrite UUID for an existing AuditTemplate."
 msgstr ""
 
-#: watcher/db/sqlalchemy/api.py:387 watcher/db/sqlalchemy/api.py:587
+#: watcher/db/sqlalchemy/api.py:386 watcher/db/sqlalchemy/api.py:586
 msgid "Cannot overwrite UUID for an existing Audit."
 msgstr ""
 
-#: watcher/db/sqlalchemy/api.py:478
+#: watcher/db/sqlalchemy/api.py:477
 msgid "Cannot overwrite UUID for an existing Action."
 msgstr ""
 
+#: watcher/db/sqlalchemy/migration.py:73
+msgid ""
+"Watcher database schema is already under version control; use upgrade() "
+"instead"
+msgstr ""
+
+#: watcher/decision_engine/model/model_root.py:37
+#: watcher/decision_engine/model/model_root.py:42
+msgid "'obj' argument type is not valid"
+msgstr ""
+
+#: watcher/decision_engine/strategy/selection/default.py:56
+#, python-format
+msgid "Incorrect mapping: could not find associated strategy for '%s'"
+msgstr ""
+
 #: watcher/objects/base.py:108
 msgid "Invalid version string"
 msgstr ""
@@ -267,7 +316,7 @@ msgstr ""
 msgid "%(objname)s object has no attribute '%(attrname)s'"
 msgstr ""
 
-#: watcher/objects/base.py:389
+#: watcher/objects/base.py:390
 #, python-format
 msgid "'%(objclass)s' object has no attribute '%(attrname)s'"
 msgstr ""