Distinguish never-spawned from never-submitted.

changes.d/6067.fix.md

@@ -0,0 +1 @@
+Fixed a bug that sometimes allowed suicide-triggered or manually removed tasks to be added back later.

cylc/flow/task_events_mgr.py

@@ -1788,6 +1788,7 @@ def _reset_job_timers(self, itask):
             itask.timeout = None
             itask.poll_timer = None
             return
+
         ctx = (itask.submit_num, itask.state.status)
         if itask.poll_timer and itask.poll_timer.ctx == ctx:
             return
@@ -1844,7 +1845,7 @@ def _reset_job_timers(self, itask):
                     message += '%d*' % (num + 1)
                 message += '%s,' % intvl_as_str(item)
             message += '...'
-        LOG.info(f"[{itask}] {message}")
+        LOG.debug(f"[{itask}] {message}")
         # Set next poll time
         self.check_poll_time(itask)
 

cylc/flow/task_pool.py

@@ -103,7 +103,7 @@ class TaskPool:
 
     ERR_TMPL_NO_TASKID_MATCH = "No matching tasks found: {0}"
     ERR_PREFIX_TASK_NOT_ON_SEQUENCE = "Invalid cycle point for task: {0}, {1}"
-    SUICIDE_MSG = "suicide"
+    SUICIDE_MSG = "suicide trigger"
 
     def __init__(
         self,
@@ -221,7 +221,7 @@ def add_to_pool(self, itask) -> None:
         self.active_tasks.setdefault(itask.point, {})
         self.active_tasks[itask.point][itask.identity] = itask
         self.active_tasks_changed = True
-        LOG.info(f"[{itask}] added to active task pool")
+        LOG.debug(f"[{itask}] added to active task pool")
 
         self.create_data_store_elements(itask)
 
@@ -807,10 +807,11 @@ def remove(self, itask, reason=None):
                 itask.flow_nums
             )
 
+        msg = "removed from active task pool"
         if reason is None:
-            msg = "task completed"
+            msg += ": completed"
         else:
-            msg = f"removed ({reason})"
+            msg += f": {reason}"
 
         if itask.is_xtrigger_sequential:
             self.xtrigger_mgr.sequential_spawn_next.discard(itask.identity)
@@ -837,7 +838,17 @@ def remove(self, itask, reason=None):
             # Event-driven final update of task_states table.
             # TODO: same for datastore (still updated by scheduler loop)
             self.workflow_db_mgr.put_update_task_state(itask)
-            LOG.info(f"[{itask}] {msg}")
+
+            level = logging.DEBUG
+            if itask.state(
+                TASK_STATUS_PREPARING,
+                TASK_STATUS_SUBMITTED,
+                TASK_STATUS_RUNNING,
+            ):
+                level = logging.WARNING
+                msg += " - active job orphaned"
+
+            LOG.log(level, f"[{itask}] {msg}")
             del itask
 
     def get_tasks(self) -> List[TaskProxy]:
@@ -1392,14 +1403,12 @@ def spawn_on_output(self, itask, output, forced=False):
                         suicide.append(t)
 
         for c_task in suicide:
-            msg = self.__class__.SUICIDE_MSG
-            if c_task.state(
-                    TASK_STATUS_PREPARING,
-                    TASK_STATUS_SUBMITTED,
-                    TASK_STATUS_RUNNING,
-                    is_held=False):
-                msg += " suiciding while active"
-            self.remove(c_task, msg)
+            self.remove(c_task, self.__class__.SUICIDE_MSG)
+
+        if suicide:
+            # Update DB now in case of very quick respawn attempt.
+            # See https://github.com/cylc/cylc-flow/issues/6066
+            self.workflow_db_mgr.process_queued_ops()
 
         self.remove_if_complete(itask, output)
 
@@ -1555,17 +1564,33 @@ def can_be_spawned(self, name: str, point: 'PointBase') -> bool:
 
     def _get_task_history(
         self, name: str, point: 'PointBase', flow_nums: Set[int]
-    ) -> Tuple[int, str, bool]:
-        """Get history of previous submits for this task."""
+    ) -> Tuple[bool, int, str, bool]:
+        """Get history of previous submits for this task.
+
+        Args:
+            name: task name
+            point: task cycle point
+            flow_nums: task flow numbers
+
+        Returns:
+            never_spawned: if task never spawned before
+            submit_num: submit number of previous submit
+            prev_status: task status of previous sumbit
+            prev_flow_wait: if previous submit was a flow-wait task
 
+        """
         info = self.workflow_db_mgr.pri_dao.select_prev_instances(
             name, str(point)
         )
         try:
             submit_num: int = max(s[0] for s in info)
         except ValueError:
-            # never spawned before in any flow
+            # never spawned in any flow
             submit_num = 0
+            never_spawned = True
+        else:
+            never_spawned = False
+            # (submit_num could still be zero, if removed before submit)
 
         prev_status: str = TASK_STATUS_WAITING
         prev_flow_wait = False
@@ -1582,7 +1607,7 @@ def _get_task_history(
                 # overlap due to merges (they'll have have same snum and
                 # f_wait); keep going to find the finished one, if any.
 
-        return submit_num, prev_status, prev_flow_wait
+        return never_spawned, submit_num, prev_status, prev_flow_wait
 
     def _load_historical_outputs(self, itask):
         """Load a task's historical outputs from the DB."""
@@ -1619,10 +1644,19 @@ def spawn_task(
         if not self.can_be_spawned(name, point):
             return None
 
-        submit_num, prev_status, prev_flow_wait = (
+        never_spawned, submit_num, prev_status, prev_flow_wait = (
             self._get_task_history(name, point, flow_nums)
         )
 
+        if (
+            not never_spawned and
+            not prev_flow_wait and
+            submit_num == 0
+        ):
+            # Previous instance removed before completing any outputs.
+            LOG.debug(f"Not spawning {point}/{name} - task removed")
+            return None
+
         itask = self._get_task_proxy_db_outputs(
             point,
             self.config.get_taskdef(name),
@@ -1653,8 +1687,6 @@ def spawn_task(
             if itask.transient and not force:
                 return None
 
-        # (else not previously finishedr, so run it)
-
         if not itask.transient:
             if (name, point) in self.tasks_to_hold:
                 LOG.info(f"[{itask}] holding (as requested earlier)")
@@ -2117,8 +2149,9 @@ def force_trigger_tasks(
             if not self.can_be_spawned(name, point):
                 continue
 
-            submit_num, _prev_status, prev_fwait = self._get_task_history(
-                name, point, flow_nums)
+            _, submit_num, _prev_status, prev_fwait = (
+                self._get_task_history(name, point, flow_nums)
+            )
 
             itask = TaskProxy(
                 self.tokens,

tests/functional/cylc-set/02-off-flow-out.t

@@ -31,14 +31,14 @@ reftest_run
 
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a1" '1/a_cold.* setting implied output: submitted'
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a2" '1/a_cold.* setting implied output: started'
-grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a3" '1/a_cold.* task completed'
+grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a3" '1/a_cold.* completed'
 
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a1" '1/b_cold.* setting implied output: submitted'
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a2" '1/b_cold.* setting implied output: started'
-grep_workflow_log_ok "${TEST_NAME_BASE}-grep-b3" '1/b_cold.* task completed'
+grep_workflow_log_ok "${TEST_NAME_BASE}-grep-b3" '1/b_cold.* completed'
 
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a1" '1/c_cold.* setting implied output: submitted'
 grep_workflow_log_ok "${TEST_NAME_BASE}-grep-a2" '1/c_cold.* setting implied output: started'
-grep_workflow_log_ok "${TEST_NAME_BASE}-grep-c3" '1/c_cold.* task completed'
+grep_workflow_log_ok "${TEST_NAME_BASE}-grep-c3" '1/c_cold.* completed'
 
 purge

tests/functional/execution-time-limit/04-polling-intervals.t

@@ -41,7 +41,7 @@ __FLOW__
 
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${WORKFLOW_NAME}"
 
-cylc play "${WORKFLOW_NAME}"
+cylc play --debug "${WORKFLOW_NAME}"
 
 poll_grep_workflow_log "INFO - DONE"
 

tests/functional/hold-release/05-release.t

@@ -65,7 +65,7 @@ init_workflow "${TEST_NAME_BASE}" <<'__FLOW_CONFIG__'
         inherit = STOP
         script = """
             cylc__job__poll_grep_workflow_log -E \
-               '1/dog1/01:succeeded.* task completed'
+               '1/dog1/01:succeeded.* completed'
             cylc stop "${CYLC_WORKFLOW_ID}"
         """
 __FLOW_CONFIG__

tests/functional/spawn-on-demand/09-set-outputs/flow.cylc

@@ -44,7 +44,7 @@
             cylc set --flow=2 --output=out1 --output=out2 "${CYLC_WORKFLOW_ID}//1/foo"
 
             # Set bar outputs after it is gone from the pool.
-            cylc__job__poll_grep_workflow_log -E "1/bar.* task completed"
+            cylc__job__poll_grep_workflow_log -E "1/bar.* completed"
             cylc set --flow=2 --output=out1 --output=out2 "${CYLC_WORKFLOW_ID}//1/bar"
         """
     [[qux, quw, fux, fuw]]

tests/integration/test_task_events_mgr.py

@@ -17,6 +17,7 @@
 from cylc.flow.task_events_mgr import TaskJobLogsRetrieveContext
 from cylc.flow.scheduler import Scheduler
 
+import logging
 from typing import Any as Fixture
 
 
@@ -51,7 +52,7 @@ async def test__reset_job_timers(
     process_execution_polling_intervals.
     """
     schd = scheduler(flow(one_conf))
-    async with start(schd):
+    async with start(schd, level=logging.DEBUG):
         itask = schd.pool.get_tasks()[0]
         itask.state.status = 'running'
         itask.platform['execution polling intervals'] = [25]