A local call waiting for a slot is reached by a stop, a delete or a cancel and ends without running; what a call emits after its flow was stopped is dropped as its result is; a node run by hand whose flow is stopped or deleted tells its caller but publishes no node_error; cancelling a node also ends its calls on workers

backend/fluksio/api/routes/flows.py

@@ -1141,14 +1141,19 @@ async def trigger_node(
 
 @router.post("/{flow_id}/nodes/{node_id}/cancel", response_model=Message)
 def cancel_node(flow_id: str, node_id: str, controller: FlowControllerDep) -> Any:
-    """Stop a node that is running right now, by killing the worker running it.
+    """Stop a node that is running right now, here or on an attached worker,
+    by killing the process running it.
 
     Idempotent on purpose: by the time a click reaches here the node may well
     have finished, and that is the outcome that was asked for.
     """
-    name = _read_flow(controller, flow_id).name
-    pool = controller.workers
-    if pool is not None and pool.cancel(f"{name}.{node_id}"):
+    node = f"{_read_flow(controller, flow_id).name}.{node_id}"
+    pool, remote = controller.workers, controller.remote
+    stopped = pool is not None and pool.cancel(node)
+    # Not ``or``: a node may have calls in both places.
+    if remote is not None and remote.cancel_node(node):
+        stopped = True
+    if stopped:
         return Message(message=f"Stopped '{node_id}'")
     return Message(message=f"'{node_id}' was not running")