Merge "Separate exception class for retriables in callbacks"

neutron/callbacks/manager.py

@@ -18,6 +18,7 @@ from oslo_utils import reflection
 from neutron._i18n import _LE
 from neutron.callbacks import events
 from neutron.callbacks import exceptions
+from neutron.db import api as db_api
 
 LOG = logging.getLogger(__name__)
 
@@ -106,6 +107,7 @@ class CallbacksManager(object):
                     del self._callbacks[resource][event][callback_id]
             del self._index[callback_id]
 
+    @db_api.reraise_as_retryrequest
     def notify(self, resource, event, trigger, **kwargs):
         """Notify all subscribed callback(s).
 

neutron/db/api.py

@@ -22,6 +22,7 @@ from oslo_db import exception as db_exc
 from oslo_db.sqlalchemy import enginefacade
 from oslo_utils import excutils
 import osprofiler.sqlalchemy
+import six
 import sqlalchemy
 from sqlalchemy.orm import exc
 
@@ -55,6 +56,21 @@ retry_db_errors = oslo_db_api.wrap_db_retry(
 )
 
 
+def reraise_as_retryrequest(f):
+    """Packs retriable exceptions into a RetryRequest."""
+
+    @six.wraps(f)
+    def wrapped(*args, **kwargs):
+        try:
+            return f(*args, **kwargs)
+        except Exception as e:
+            with excutils.save_and_reraise_exception() as ctx:
+                if is_retriable(e):
+                    ctx.reraise = False
+                    raise db_exc.RetryRequest(e)
+    return wrapped
+
+
 def _is_nested_instance(e, etypes):
     """Check if exception or its inner excepts are an instance of etypes."""
     return (isinstance(e, etypes) or

neutron/tests/unit/callbacks/test_manager.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import mock
+from oslo_db import exception as db_exc
 
 from neutron.callbacks import events
 from neutron.callbacks import exceptions
@@ -35,6 +36,10 @@ def callback_raise(*args, **kwargs):
     raise Exception()
 
 
+def callback_raise_retriable(*args, **kwargs):
+    raise db_exc.DBDeadlock()
+
+
 class CallBacksManagerTestCase(base.BaseTestCase):
 
     def setUp(self):
@@ -173,6 +178,12 @@ class CallBacksManagerTestCase(base.BaseTestCase):
                               resources.PORT, events.BEFORE_CREATE, self)
         self.assertIsInstance(e.errors[0], exceptions.NotificationError)
 
+    def test_notify_handle_retriable_exception(self):
+        self.manager.subscribe(
+            callback_raise_retriable, resources.PORT, events.BEFORE_CREATE)
+        self.assertRaises(db_exc.RetryRequest, self.manager.notify,
+                          resources.PORT, events.BEFORE_CREATE, self)
+
     def test_notify_called_once_with_no_failures(self):
         with mock.patch.object(self.manager, '_notify_loop') as n:
             n.return_value = False