Remove unnecessary database transaction from Scheduler

Change-Id: I08f0fcd67e0cd0e40e76ed6cfc7bb214096a2c16
Closes-Bug: #1484521

mistral/engine/policies.py

@@ -438,32 +438,32 @@ class ConcurrencyPolicy(base.TaskPolicy):
 def _continue_task(task_ex_id):
     from mistral.engine import task_handler
 
-    # TODO(rakhmerov): It must be done in TX after Scheduler is fixed.
-    task_handler.continue_task(db_api.get_task_execution(task_ex_id))
+    with db_api.transaction():
+        task_handler.continue_task(db_api.get_task_execution(task_ex_id))
 
 
 def _complete_task(task_ex_id, state, state_info):
     from mistral.engine import task_handler
 
-    # TODO(rakhmerov): It must be done in TX after Scheduler is fixed.
-    task_handler.complete_task(
-        db_api.get_task_execution(task_ex_id),
-        state,
-        state_info
-    )
+    with db_api.transaction():
+        task_handler.complete_task(
+            db_api.get_task_execution(task_ex_id),
+            state,
+            state_info
+        )
 
 
 def _fail_task_if_incomplete(task_ex_id, timeout):
     from mistral.engine import task_handler
 
-    # TODO(rakhmerov): It must be done in TX after Scheduler is fixed.
-    task_ex = db_api.get_task_execution(task_ex_id)
+    with db_api.transaction():
+        task_ex = db_api.get_task_execution(task_ex_id)
 
-    if not states.is_completed(task_ex.state):
-        msg = 'Task timed out [timeout(s)=%s].' % timeout
+        if not states.is_completed(task_ex.state):
+            msg = 'Task timed out [timeout(s)=%s].' % timeout
 
-        task_handler.complete_task(
-            db_api.get_task_execution(task_ex_id),
-            states.ERROR,
-            msg
-        )
+            task_handler.complete_task(
+                db_api.get_task_execution(task_ex_id),
+                states.ERROR,
+                msg
+            )

mistral/services/scheduler.py

@@ -162,23 +162,19 @@ class CallScheduler(periodic_task.PeriodicTasks):
             )
 
         for (target_auth_context, target_method, method_args) in delayed_calls:
-            # TODO(rakhmerov): https://bugs.launchpad.net/mistral/+bug/1484521
-            # Transaction is needed here because some of the
-            # target_method can use the DB.
-            with db_api.transaction():
-                try:
-                    # Set the correct context for the method.
-                    context.set_ctx(
-                        context.MistralContext(target_auth_context)
-                    )
+            try:
+                # Set the correct context for the method.
+                context.set_ctx(
+                    context.MistralContext(target_auth_context)
+                )
 
-                    # Call the method.
-                    target_method(**method_args)
-                except Exception as e:
-                    LOG.exception("Delayed call failed [exception=%s]: %s", e)
-                finally:
-                    # Remove context.
-                    context.set_ctx(None)
+                # Call the method.
+                target_method(**method_args)
+            except Exception as e:
+                LOG.exception("Delayed call failed [exception=%s]: %s", e)
+            finally:
+                # Remove context.
+                context.set_ctx(None)
 
         with db_api.transaction():
             for call in calls_to_make:

mistral/tests/unit/engine/base.py

@@ -31,7 +31,7 @@ LOG = logging.getLogger(__name__)
 
 # Default delay and timeout in seconds for await_xxx() functions.
 DEFAULT_DELAY = 1
-DEFAULT_TIMEOUT = 20
+DEFAULT_TIMEOUT = 30
 
 
 def launch_engine_server(transport, engine):
@@ -114,7 +114,7 @@ class EngineTestCase(base.DbTestCase):
             eventlet.spawn(launch_executor_server, transport, self.executor),
         ]
 
-        self.addOnException(self.print_workflow_executions)
+        self.addOnException(self.print_executions)
 
         # Start scheduler.
         scheduler_thread_group = scheduler.setup()
@@ -128,9 +128,10 @@ class EngineTestCase(base.DbTestCase):
         [thread.kill() for thread in self.threads]
 
     @staticmethod
-    def print_workflow_executions(exc_info):
+    def print_executions(exc_info):
         print("\nEngine test case exception occurred: %s" % exc_info[1])
         print("Exception type: %s" % exc_info[0])
+
         print("\nPrinting workflow executions...")
 
         wf_execs = db_api.get_workflow_executions()
@@ -167,6 +168,22 @@ class EngineTestCase(base.DbTestCase):
                          a.output)
                     )
 
+        print("\nPrinting standalone action executions...")
+
+        a_execs = db_api.get_action_executions(task_execution_id=None)
+
+        for a in a_execs:
+            print(
+                "\t\t%s [id=%s, state=%s, state_info=%s, accepted=%s,"
+                " output=%s]" %
+                (a.name,
+                 a.id,
+                 a.state,
+                 a.state_info,
+                 a.accepted,
+                 a.output)
+            )
+
     # Various methods for abstract execution objects.
 
     def is_execution_in_state(self, ex_id, state):