Merge "Allocation API: allow skipping retries in TaskManager"

ironic/conductor/task_manager.py

@@ -149,20 +149,16 @@ def require_exclusive_lock(f):
     return wrapper
 
 
-def acquire(context, node_id, shared=False, purpose='unspecified action'):
+def acquire(context, *args, **kwargs):
     """Shortcut for acquiring a lock on a Node.
 
     :param context: Request context.
-    :param node_id: ID or UUID of node to lock.
-    :param shared: Boolean indicating whether to take a shared or exclusive
-                   lock. Default: False.
-    :param purpose: human-readable purpose to put to debug logs.
     :returns: An instance of :class:`TaskManager`.
 
     """
     # NOTE(lintan): This is a workaround to set the context of periodic tasks.
     context.ensure_thread_contain_context()
-    return TaskManager(context, node_id, shared=shared, purpose=purpose)
+    return TaskManager(context, *args, **kwargs)
 
 
 class TaskManager(object):
@@ -174,7 +170,7 @@ class TaskManager(object):
     """
 
     def __init__(self, context, node_id, shared=False,
-                 purpose='unspecified action'):
+                 purpose='unspecified action', retry=True):
         """Create a new TaskManager.
 
         Acquire a lock on a node. The lock can be either shared or
@@ -187,6 +183,7 @@ class TaskManager(object):
         :param shared: Boolean indicating whether to take a shared or exclusive
                        lock. Default: False.
         :param purpose: human-readable purpose to put to debug logs.
+        :param retry: whether to retry locking if it fails. Default: True.
         :raises: DriverNotFound
         :raises: InterfaceNotFoundInEntrypoint
         :raises: NodeNotFound
@@ -201,6 +198,7 @@ class TaskManager(object):
         self._node = None
         self.node_id = node_id
         self.shared = shared
+        self._retry = retry
 
         self.fsm = states.machine.copy()
         self._purpose = purpose
@@ -251,12 +249,17 @@ class TaskManager(object):
     def _lock(self):
         self._debug_timer.restart()
 
+        if self._retry:
+            attempts = CONF.conductor.node_locked_retry_attempts
+        else:
+            attempts = 1
+
         # NodeLocked exceptions can be annoying. Let's try to alleviate
         # some of that pain by retrying our lock attempts. The retrying
         # module expects a wait_fixed value in milliseconds.
         @retrying.retry(
             retry_on_exception=lambda e: isinstance(e, exception.NodeLocked),
-            stop_max_attempt_number=CONF.conductor.node_locked_retry_attempts,
+            stop_max_attempt_number=attempts,
             wait_fixed=CONF.conductor.node_locked_retry_interval * 1000)
         def reserve_node():
             self.node = objects.Node.reserve(self.context, CONF.host,

ironic/tests/unit/conductor/test_task_manager.py

@@ -159,6 +159,28 @@ class TaskManagerTestCase(db_base.DbTestCase):
         reserve_mock.assert_has_calls(expected_calls)
         self.assertEqual(2, reserve_mock.call_count)
 
+    def test_excl_lock_exception_no_retries(
+            self, get_voltgt_mock, get_volconn_mock, get_portgroups_mock,
+            get_ports_mock, build_driver_mock,
+            reserve_mock, release_mock, node_get_mock):
+        retry_attempts = 3
+        self.config(node_locked_retry_attempts=retry_attempts,
+                    group='conductor')
+
+        # Fail on the first lock attempt, succeed on the second.
+        reserve_mock.side_effect = [exception.NodeLocked(node='foo',
+                                                         host='foo'),
+                                    self.node]
+
+        self.assertRaises(exception.NodeLocked,
+                          task_manager.TaskManager,
+                          self.context,
+                          'fake-node-id',
+                          retry=False)
+
+        reserve_mock.assert_called_once_with(self.context, self.host,
+                                             'fake-node-id')
+
     def test_excl_lock_reserve_exception(
             self, get_voltgt_mock, get_volconn_mock, get_portgroups_mock,
             get_ports_mock, build_driver_mock,