Trigger now if workflow paused

changes.d/6499.feat.md

@@ -0,0 +1 @@
+Manually triggered tasks now run immediately even if the workflow is paused.

cylc/flow/commands.py

@@ -338,7 +338,7 @@
 
     # flush out preparing tasks before attempting reload
     schd.reload_pending = 'waiting for pending tasks to submit'
-    while schd.release_queued_tasks():
+    while schd.release_tasks_to_run():
         # Run the subset of main-loop functionality required to push
         # preparing through the submission pipeline and keep the workflow
         # responsive (e.g. to the `cylc stop` command).
@@ -446,9 +446,17 @@
     flow: List[str],
     flow_wait: bool = False,
     flow_descr: Optional[str] = None,
+    on_resume: bool = False
 ):
     """Manual task trigger."""
     validate.is_tasks(tasks)
     validate.flow_opts(flow, flow_wait)
+    if on_resume:
+        LOG.warning(
+            "The --on-resume option is deprecated and will be removed "
+            "at Cylc 8.5."
+        )
     yield
-    yield schd.pool.force_trigger_tasks(tasks, flow, flow_wait, flow_descr)
+    yield schd.pool.force_trigger_tasks(
+        tasks, flow, flow_wait, flow_descr, on_resume
+    )

cylc/flow/network/schema.py

@@ -2213,20 +2213,32 @@ class Arguments(TaskMutation.Arguments, FlowMutationArguments):
 class Trigger(Mutation, TaskMutation):
     class Meta:
         description = sstrip('''
-            Manually trigger tasks.
+            Manually trigger tasks, even in a paused workflow.
 
-            Warning: waiting tasks that are queue-limited will be queued if
-            triggered, to submit as normal when released by the queue; queued
-            tasks will submit immediately if triggered, even if that violates
-            the queue limit (so you may need to trigger a queue-limited task
-            twice to get it to submit immediately).
+            Triggering a task that is not yet queued will queue it.
+
+            Triggering a queued task runs it immediately.
+
+            Cylc queues restrict the number of jobs that can be active
+            (submitted or running) at once. They release tasks to run
+            when their active task count drops below the queue limit.
+            So, depending on the active task count, you may need to
+            trigger a task twice to make it run immediately.
+
+            Attempts to trigger active tasks will be ignored.
 
             Valid for: paused, running workflows.
         ''')
         resolver = partial(mutator, command='force_trigger_tasks')
 
     class Arguments(TaskMutation.Arguments, FlowMutationArguments):
-        ...
+        on_resume = Boolean(
+            default_value=False,
+            description=sstrip('''
+                If the workflow is paused, wait until it is resumed before
+                running the triggered task(s).
+            ''')
+        )
 
 
 def _mut_field(cls):

cylc/flow/scheduler.py

@@ -677,6 +677,22 @@
                     self.restart_remote_init()
                     await commands.run_cmd(commands.poll_tasks(self, ['*/*']))
 
+                    # If we shut down with manually triggered waiting tasks,
+                    # submit them to run now.
+                    # NOTE: this will run tasks that were triggered with
+                    # the trigger "--on-resume" option, even if the workflow
+                    # is restarted as paused. Option to be removed at 8.5.0.
+                    pre_prep_tasks = []
+                    for itask in self.pool.get_tasks():
+                        if (
+                            itask.is_manual_submit
+                            and itask.state(TASK_STATUS_WAITING)
+                        ):
+                            itask.waiting_on_job_prep = True
+                            pre_prep_tasks.append(itask)
+
+                    self.start_job_submission(pre_prep_tasks)
+
             self.run_event_handlers(self.EVENT_STARTUP, 'workflow starting')
             await asyncio.gather(
                 *main_loop.get_runners(
@@ -778,10 +794,10 @@
                 self.uuid_str = dict(params)['uuid_str']
             else:
                 self.uuid_str = str(uuid4())
+            self.task_events_mgr.uuid_str = self.uuid_str
 
             self._configure_contact()
             await self.configure(params)
-            self.task_events_mgr.uuid_str = self.uuid_str
         except (KeyboardInterrupt, asyncio.CancelledError, Exception) as exc:
             await self.handle_exception(exc)
 
@@ -865,6 +881,7 @@
             self.xtrigger_mgr.load_xtrigger_for_restart)
         self.workflow_db_mgr.pri_dao.select_abs_outputs_for_restart(
             self.pool.load_abs_outputs_for_restart)
+
         self.pool.load_db_tasks_to_hold()
         self.pool.update_flow_mgr()
 
@@ -1434,8 +1451,8 @@
             return
         self.workflow_event_handler.handle(self, event, str(reason))
 
-    def release_queued_tasks(self) -> bool:
-        """Release queued tasks, and submit jobs.
+    def release_tasks_to_run(self) -> bool:
+        """Release queued or manually submitted tasks, and submit jobs.
 
         The task queue manages references to task proxies in the task pool.
 
@@ -1459,13 +1476,24 @@
             submission).
 
         """
+        pre_prep_tasks: Set['TaskProxy'] = set()
         if (
-            not self.is_paused
-            and self.stop_mode is None
+            self.stop_mode is None
             and self.auto_restart_time is None
             and self.reload_pending is False
         ):
-            pre_prep_tasks = self.pool.release_queued_tasks()
+            if self.pool.tasks_to_trigger_now:
+                # manually triggered tasks to run now, workflow paused or not
+                pre_prep_tasks.update(self.pool.tasks_to_trigger_now)
+                self.pool.tasks_to_trigger_now = set()
+
+            if not self.is_paused:
+                # release queued tasks
+                pre_prep_tasks.update(self.pool.release_queued_tasks())
+                if self.pool.tasks_to_trigger_on_resume:
+                    # and manually triggered tasks to run once workflow resumed
+                    pre_prep_tasks.update(self.pool.tasks_to_trigger_on_resume)
+                    self.pool.tasks_to_trigger_on_resume = set()
 
         elif (
             (
@@ -1477,19 +1505,30 @@
                 self.reload_pending
             )
         ):
-            # don't release queued tasks, finish processing preparing tasks
-            pre_prep_tasks = [
+            # finish processing preparing tasks first
+            pre_prep_tasks = {
                 itask for itask in self.pool.get_tasks()
                 if itask.state(TASK_STATUS_PREPARING)
-            ]
+            }
 
         # Return, if no tasks to submit.
         else:
             return False
+
         if not pre_prep_tasks:
             return False
 
-        # Start the job submission process.
+        return self.start_job_submission(pre_prep_tasks)
+
+    def start_job_submission(self, itasks: 'Iterable[TaskProxy]') -> bool:
+        """Start the job submission process for some tasks.
+
+        Return True if any were started, else False.
+
+        """
+        if self.stop_mode is not None:
+            return False
+
         self.is_updated = True
         self.reset_inactivity_timer()
 
@@ -1499,9 +1538,10 @@
         log = LOG.debug
         if self.options.reftest or self.options.genref:
             log = LOG.info
+
         for itask in self.task_job_mgr.submit_task_jobs(
             self.workflow,
-            pre_prep_tasks,
+            itasks,
             self.server.curve_auth,
             self.server.client_pub_key_dir,
             run_mode=self.get_run_mode()
@@ -1743,7 +1783,7 @@
                 self.broadcast_mgr.check_ext_triggers(
                     itask, self.ext_trigger_queue)
 
-            if itask.is_ready_to_run():
+            if itask.is_ready_to_run() and not itask.is_manual_submit:
                 self.pool.queue_task(itask)
 
         if self.xtrigger_mgr.sequential_spawn_next:
@@ -1752,7 +1792,7 @@
         if self.xtrigger_mgr.do_housekeeping:
             self.xtrigger_mgr.housekeep(self.pool.get_tasks())
         self.pool.clock_expire_tasks()
-        self.release_queued_tasks()
+        self.release_tasks_to_run()
 
         if (
             self.get_run_mode() == RunMode.SIMULATION

cylc/flow/scripts/pause.py

@@ -18,9 +18,10 @@
 
 """cylc pause [OPTIONS] ARGS
 
-Pause a workflow.
+Suspend automatic job submission.
 
-This suspends submission of all tasks in a workflow.
+Manual triggering can still run tasks immediately, even if the workflow is
+paused.
 
 Examples:
   # pause my_workflow

cylc/flow/scripts/trigger.py

@@ -17,11 +17,17 @@
 
 """cylc trigger [OPTIONS] ARGS
 
-Force tasks to run regardless of prerequisites.
+Force task(s) to run regardless of prerequisites, even in a paused workflow.
 
-* Triggering an unqueued waiting task queues it, regardless of prerequisites.
-* Triggering a queued task submits it, regardless of queue limiting.
-* Triggering an active task has no effect (it already triggered).
+Triggering a task that is not yet queued will queue it.
+
+Triggering a queued task runs it immediately.
+
+Cylc queues restrict the number of jobs that can be active (submitted or
+running) at once. They release tasks to run when their active task count
+drops below the queue limit.
+
+Attempts to trigger active tasks will be ignored.
 
 Examples:
   # trigger task foo in cycle 1234 in test
@@ -74,13 +80,15 @@
   $flow: [Flow!],
   $flowWait: Boolean,
   $flowDescr: String,
+  $onResume: Boolean,
 ) {
   trigger (
     workflows: $wFlows,
     tasks: $tasks,
     flow: $flow,
     flowWait: $flowWait,
-    flowDescr: $flowDescr
+    flowDescr: $flowDescr,
+    onResume: $onResume,
   ) {
     result
   }
@@ -96,7 +104,20 @@ def get_option_parser() -> COP:
         multiworkflow=True,
         argdoc=[FULL_ID_MULTI_ARG_DOC],
     )
+
     add_flow_opts(parser)
+
+    parser.add_option(
+        "--on-resume",
+        help=(
+            "If the workflow is paused, wait until it is resumed before "
+            "running the triggered task(s). DEPRECATED - this will be "
+            "removed at Cylc 8.5."
+        ),
+        action="store_true",
+        default=False,
+        dest="on_resume"
+    )
     return parser
 
 
@@ -114,6 +135,7 @@ async def run(options: 'Values', workflow_id: str, *tokens_list):
             'flow': options.flow,
             'flowWait': options.flow_wait,
             'flowDescr': options.flow_descr,
+            'onResume': options.on_resume,
         }
     }
     return await pclient.async_request('graphql', mutation_kwargs)