backend/services/scheduler.py

@@ -680,31 +680,52 @@ class SchedulerService:
                 logger.info(f"[CYCLE] New measurement started, session {new_session.id}")
 
                 # Step 6b: Verify the meter actually resumed measuring (fresh DOD).
-                # Polling is still paused here, so query directly.  Advisory: a
-                # failure alerts loudly but doesn't fail the cycle (DOD reads can
-                # be transiently flaky); the keepalive poll re-confirms within ~10s.
+                # Polling is still paused here, so query directly.  If it didn't
+                # resume, retry ONCE with a plain start (start_recording — does NOT
+                # re-index, unlike start_cycle) before alerting: a meter left
+                # stopped overnight is the costly failure, and a transient restart
+                # hiccup is common on the NL-43.  We retry only on a *confident*
+                # not-measuring reading — never on a failed/inconclusive DOD read —
+                # so a flaky read can't disrupt an already-running measurement.
                 if action.device_type == "slm":
-                    try:
-                        await asyncio.sleep(2)
-                        live = await self.device_controller.get_live_data(unit_id, action.device_type)
-                        state = ((live or {}).get("measurement_state")
-                                 or ((live or {}).get("data") or {}).get("measurement_state") or "")
-                        measuring = str(state).strip().lower() in ("start", "measure", "measuring", "run", "running")
-                        result["steps"]["restart_verified"] = measuring
-                        if measuring:
-                            logger.info(f"[CYCLE] Restart verified — {unit_id} is measuring (state={state}).")
-                        else:
-                            logger.error(f"[CYCLE] Restart NOT verified for {unit_id} — state={state!r}")
-                            try:
-                                get_alert_service(db).create_schedule_failed_alert(
-                                    schedule_id=action.id, action_type="cycle", unit_id=unit_id,
-                                    error_message=f"Meter did not resume measuring after the cycle (state={state!r}).",
-                                    project_id=action.project_id, location_id=action.location_id,
-                                )
-                            except Exception as ae:
-                                logger.warning(f"[CYCLE] restart-verify alert failed: {ae}")
-                    except Exception as e:
-                        logger.warning(f"[CYCLE] Restart verification skipped (DOD read failed): {e}")
+                    async def _check_measuring():
+                        """Return (measuring, state); measuring is None if the DOD read failed."""
+                        try:
+                            await asyncio.sleep(2)
+                            live = await self.device_controller.get_live_data(unit_id, action.device_type)
+                            state = ((live or {}).get("measurement_state")
+                                     or ((live or {}).get("data") or {}).get("measurement_state") or "")
+                            ok = str(state).strip().lower() in ("start", "measure", "measuring", "run", "running")
+                            return ok, state
+                        except Exception as e:
+                            logger.warning(f"[CYCLE] Restart-verify DOD read failed: {e}")
+                            return None, None
+
+                    measuring, state = await _check_measuring()
+                    if measuring is False:
+                        logger.warning(f"[CYCLE] {unit_id} not measuring after restart (state={state!r}) — retrying start once.")
+                        result["steps"]["restart_retry"] = True
+                        try:
+                            await self.device_controller.start_recording(unit_id, action.device_type)
+                            measuring, state = await _check_measuring()
+                        except Exception as e:
+                            logger.error(f"[CYCLE] Restart retry (start_recording) failed for {unit_id}: {e}")
+
+                    result["steps"]["restart_verified"] = measuring
+                    if measuring:
+                        logger.info(f"[CYCLE] Restart verified — {unit_id} is measuring (state={state}).")
+                    elif measuring is False:
+                        logger.error(f"[CYCLE] Restart NOT verified for {unit_id} after retry — state={state!r}")
+                        try:
+                            get_alert_service(db).create_schedule_failed_alert(
+                                schedule_id=action.id, action_type="cycle", unit_id=unit_id,
+                                error_message=f"Meter did not resume measuring after the cycle + one retry (state={state!r}).",
+                                project_id=action.project_id, location_id=action.location_id,
+                            )
+                        except Exception as ae:
+                            logger.warning(f"[CYCLE] restart-verify alert failed: {ae}")
+                    else:
+                        logger.warning(f"[CYCLE] Restart verification inconclusive for {unit_id} (DOD read failed); keepalive poll will re-confirm.")
 
             except Exception as e:
                 logger.error(f"[CYCLE] Start failed: {e}")