Skip to content

prefect.server.api.flow_runs

Routes for interacting with flow run objects.

average_flow_run_lateness async

Query for average flow-run lateness in seconds.

Source code in prefect/server/api/flow_runs.py
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
@router.post("/lateness")
async def average_flow_run_lateness(
    flows: Optional[schemas.filters.FlowFilter] = None,
    flow_runs: Optional[schemas.filters.FlowRunFilter] = None,
    task_runs: Optional[schemas.filters.TaskRunFilter] = None,
    deployments: Optional[schemas.filters.DeploymentFilter] = None,
    work_pools: Optional[schemas.filters.WorkPoolFilter] = None,
    work_pool_queues: Optional[schemas.filters.WorkQueueFilter] = None,
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> Optional[float]:
    """
    Query for average flow-run lateness in seconds.
    """
    async with db.session_context() as session:
        if db.dialect.name == "sqlite":
            # Since we want an _average_ of the lateness we're unable to use
            # the existing FlowRun.expected_start_time_delta property as it
            # returns a timedelta and SQLite is unable to properly deal with it
            # and always returns 1970.0 as the average. This copies the same
            # logic but ensures that it returns the number of seconds instead
            # so it's compatible with SQLite.
            base_query = sa.case(
                (
                    db.FlowRun.start_time > db.FlowRun.expected_start_time,
                    sa.func.strftime("%s", db.FlowRun.start_time)
                    - sa.func.strftime("%s", db.FlowRun.expected_start_time),
                ),
                (
                    db.FlowRun.start_time.is_(None)
                    & db.FlowRun.state_type.notin_(schemas.states.TERMINAL_STATES)
                    & (db.FlowRun.expected_start_time < sa.func.datetime("now")),
                    sa.func.strftime("%s", sa.func.datetime("now"))
                    - sa.func.strftime("%s", db.FlowRun.expected_start_time),
                ),
                else_=0,
            )
        else:
            base_query = db.FlowRun.estimated_start_time_delta

        query = await models.flow_runs._apply_flow_run_filters(
            sa.select(sa.func.avg(base_query)),
            flow_filter=flows,
            flow_run_filter=flow_runs,
            task_run_filter=task_runs,
            deployment_filter=deployments,
            work_pool_filter=work_pools,
            work_queue_filter=work_pool_queues,
        )
        result = await session.execute(query)

        avg_lateness = result.scalar()

        if avg_lateness is None:
            return None
        elif isinstance(avg_lateness, datetime.timedelta):
            return avg_lateness.total_seconds()
        else:
            return avg_lateness

count_flow_runs async

Query for flow runs.

Source code in prefect/server/api/flow_runs.py
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
@router.post("/count")
async def count_flow_runs(
    flows: schemas.filters.FlowFilter = None,
    flow_runs: schemas.filters.FlowRunFilter = None,
    task_runs: schemas.filters.TaskRunFilter = None,
    deployments: schemas.filters.DeploymentFilter = None,
    work_pools: schemas.filters.WorkPoolFilter = None,
    work_pool_queues: schemas.filters.WorkQueueFilter = None,
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> int:
    """
    Query for flow runs.
    """
    async with db.session_context() as session:
        return await models.flow_runs.count_flow_runs(
            session=session,
            flow_filter=flows,
            flow_run_filter=flow_runs,
            task_run_filter=task_runs,
            deployment_filter=deployments,
            work_pool_filter=work_pools,
            work_queue_filter=work_pool_queues,
        )

create_flow_run async

Create a flow run. If a flow run with the same flow_id and idempotency key already exists, the existing flow run will be returned.

If no state is provided, the flow run will be created in a PENDING state.

Source code in prefect/server/api/flow_runs.py
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
@router.post("/")
async def create_flow_run(
    flow_run: schemas.actions.FlowRunCreate,
    db: PrefectDBInterface = Depends(provide_database_interface),
    response: Response = None,
    created_by: Optional[schemas.core.CreatedBy] = Depends(dependencies.get_created_by),
    orchestration_parameters: Dict[str, Any] = Depends(
        orchestration_dependencies.provide_flow_orchestration_parameters
    ),
    api_version=Depends(dependencies.provide_request_api_version),
) -> schemas.responses.FlowRunResponse:
    """
    Create a flow run. If a flow run with the same flow_id and
    idempotency key already exists, the existing flow run will be returned.

    If no state is provided, the flow run will be created in a PENDING state.
    """
    # hydrate the input model into a full flow run / state model
    flow_run = schemas.core.FlowRun(**flow_run.dict(), created_by=created_by)

    # pass the request version to the orchestration engine to support compatibility code
    orchestration_parameters.update({"api-version": api_version})

    if not flow_run.state:
        flow_run.state = schemas.states.Pending()

    now = pendulum.now("UTC")

    async with db.session_context(begin_transaction=True) as session:
        model = await models.flow_runs.create_flow_run(
            session=session,
            flow_run=flow_run,
            orchestration_parameters=orchestration_parameters,
        )
        if model.created >= now:
            response.status_code = status.HTTP_201_CREATED

        return schemas.responses.FlowRunResponse.from_orm(model)

create_flow_run_input async

Create a key/value input for a flow run.

Source code in prefect/server/api/flow_runs.py
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
@router.post("/{id}/input", status_code=status.HTTP_201_CREATED)
async def create_flow_run_input(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    key: str = Body(..., description="The input key"),
    value: bytes = Body(..., description="The value of the input"),
    sender: Optional[str] = Body(None, description="The sender of the input"),
    db: PrefectDBInterface = Depends(provide_database_interface),
):
    """
    Create a key/value input for a flow run.
    """
    async with db.session_context() as session:
        try:
            await models.flow_run_input.create_flow_run_input(
                session=session,
                flow_run_input=schemas.core.FlowRunInput(
                    flow_run_id=flow_run_id,
                    key=key,
                    sender=sender,
                    value=value.decode(),
                ),
            )
            await session.commit()

        except IntegrityError as exc:
            if "unique constraint" in str(exc).lower():
                raise HTTPException(
                    status_code=status.HTTP_409_CONFLICT,
                    detail="A flow run input with this key already exists.",
                )
            else:
                raise HTTPException(
                    status_code=status.HTTP_404_NOT_FOUND, detail="Flow run not found"
                )

delete_flow_run async

Delete a flow run by id.

Source code in prefect/server/api/flow_runs.py
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_flow_run(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    db: PrefectDBInterface = Depends(provide_database_interface),
):
    """
    Delete a flow run by id.
    """
    async with db.session_context(begin_transaction=True) as session:
        result = await models.flow_runs.delete_flow_run(
            session=session, flow_run_id=flow_run_id
        )
    if not result:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Flow run not found"
        )

delete_flow_run_input async

Delete a flow run input

Source code in prefect/server/api/flow_runs.py
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
@router.delete("/{id}/input/{key}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_flow_run_input(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    key: str = Path(..., description="The input key", alias="key"),
    db: PrefectDBInterface = Depends(provide_database_interface),
):
    """
    Delete a flow run input
    """

    async with db.session_context() as session:
        deleted = await models.flow_run_input.delete_flow_run_input(
            session=session, flow_run_id=flow_run_id, key=key
        )
        await session.commit()

        if not deleted:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND, detail="Flow run input not found"
            )

filter_flow_run_input async

Filter flow run inputs by key prefix

Source code in prefect/server/api/flow_runs.py
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
@router.post("/{id}/input/filter")
async def filter_flow_run_input(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    prefix: str = Body(..., description="The input key prefix", embed=True),
    limit: int = Body(
        1, description="The maximum number of results to return", embed=True
    ),
    exclude_keys: List[str] = Body(
        [], description="Exclude inputs with these keys", embed=True
    ),
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> List[schemas.core.FlowRunInput]:
    """
    Filter flow run inputs by key prefix
    """
    async with db.session_context() as session:
        return await models.flow_run_input.filter_flow_run_input(
            session=session,
            flow_run_id=flow_run_id,
            prefix=prefix,
            limit=limit,
            exclude_keys=exclude_keys,
        )

flow_run_history async

Query for flow run history data across a given range and interval.

Source code in prefect/server/api/flow_runs.py
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
@router.post("/history")
async def flow_run_history(
    history_start: DateTimeTZ = Body(..., description="The history's start time."),
    history_end: DateTimeTZ = Body(..., description="The history's end time."),
    history_interval: datetime.timedelta = Body(
        ...,
        description=(
            "The size of each history interval, in seconds. Must be at least 1 second."
        ),
        alias="history_interval_seconds",
    ),
    flows: schemas.filters.FlowFilter = None,
    flow_runs: schemas.filters.FlowRunFilter = None,
    task_runs: schemas.filters.TaskRunFilter = None,
    deployments: schemas.filters.DeploymentFilter = None,
    work_pools: schemas.filters.WorkPoolFilter = None,
    work_queues: schemas.filters.WorkQueueFilter = None,
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> List[schemas.responses.HistoryResponse]:
    """
    Query for flow run history data across a given range and interval.
    """
    if history_interval < datetime.timedelta(seconds=1):
        raise HTTPException(
            status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail="History interval must not be less than 1 second.",
        )

    async with db.session_context() as session:
        return await run_history(
            session=session,
            run_type="flow_run",
            history_start=history_start,
            history_end=history_end,
            history_interval=history_interval,
            flows=flows,
            flow_runs=flow_runs,
            task_runs=task_runs,
            deployments=deployments,
            work_pools=work_pools,
            work_queues=work_queues,
        )

read_flow_run async

Get a flow run by id.

Source code in prefect/server/api/flow_runs.py
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
@router.get("/{id}")
async def read_flow_run(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> schemas.responses.FlowRunResponse:
    """
    Get a flow run by id.
    """
    async with db.session_context() as session:
        flow_run = await models.flow_runs.read_flow_run(
            session=session, flow_run_id=flow_run_id
        )
        if not flow_run:
            raise HTTPException(status.HTTP_404_NOT_FOUND, detail="Flow run not found")
        return schemas.responses.FlowRunResponse.from_orm(flow_run)

read_flow_run_graph_v1 async

Get a task run dependency map for a given flow run.

Source code in prefect/server/api/flow_runs.py
290
291
292
293
294
295
296
297
298
299
300
301
@router.get("/{id}/graph")
async def read_flow_run_graph_v1(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> List[DependencyResult]:
    """
    Get a task run dependency map for a given flow run.
    """
    async with db.session_context() as session:
        return await models.flow_runs.read_task_run_dependencies(
            session=session, flow_run_id=flow_run_id
        )

read_flow_run_graph_v2 async

Get a graph of the tasks and subflow runs for the given flow run

Source code in prefect/server/api/flow_runs.py
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
@router.get("/{id:uuid}/graph-v2")
async def read_flow_run_graph_v2(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    since: datetime.datetime = Query(
        datetime.datetime.min,
        description="Only include runs that start or end after this time.",
    ),
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> Graph:
    """
    Get a graph of the tasks and subflow runs for the given flow run
    """
    async with db.session_context() as session:
        try:
            return await read_flow_run_graph(
                session=session,
                flow_run_id=flow_run_id,
                since=since,
            )
        except FlowRunGraphTooLarge as e:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=str(e),
            )

read_flow_run_input async

Create a value from a flow run input

Source code in prefect/server/api/flow_runs.py
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
@router.get("/{id}/input/{key}")
async def read_flow_run_input(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    key: str = Path(..., description="The input key", alias="key"),
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> PlainTextResponse:
    """
    Create a value from a flow run input
    """

    async with db.session_context() as session:
        flow_run_input = await models.flow_run_input.read_flow_run_input(
            session=session, flow_run_id=flow_run_id, key=key
        )

    if flow_run_input:
        return PlainTextResponse(flow_run_input.value)
    else:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Flow run input not found"
        )

read_flow_runs async

Query for flow runs.

Source code in prefect/server/api/flow_runs.py
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
@router.post("/filter", response_class=ORJSONResponse)
async def read_flow_runs(
    sort: schemas.sorting.FlowRunSort = Body(schemas.sorting.FlowRunSort.ID_DESC),
    limit: int = dependencies.LimitBody(),
    offset: int = Body(0, ge=0),
    flows: schemas.filters.FlowFilter = None,
    flow_runs: schemas.filters.FlowRunFilter = None,
    task_runs: schemas.filters.TaskRunFilter = None,
    deployments: schemas.filters.DeploymentFilter = None,
    work_pools: schemas.filters.WorkPoolFilter = None,
    work_pool_queues: schemas.filters.WorkQueueFilter = None,
    db: PrefectDBInterface = Depends(provide_database_interface),
) -> List[schemas.responses.FlowRunResponse]:
    """
    Query for flow runs.
    """
    async with db.session_context() as session:
        db_flow_runs = await models.flow_runs.read_flow_runs(
            session=session,
            flow_filter=flows,
            flow_run_filter=flow_runs,
            task_run_filter=task_runs,
            deployment_filter=deployments,
            work_pool_filter=work_pools,
            work_queue_filter=work_pool_queues,
            offset=offset,
            limit=limit,
            sort=sort,
        )

        # Instead of relying on fastapi.encoders.jsonable_encoder to convert the
        # response to JSON, we do so more efficiently ourselves.
        # In particular, the FastAPI encoder is very slow for large, nested objects.
        # See: https://github.com/tiangolo/fastapi/issues/1224
        encoded = [
            schemas.responses.FlowRunResponse.from_orm(fr).dict(json_compatible=True)
            for fr in db_flow_runs
        ]
        return ORJSONResponse(content=encoded)

resume_flow_run async

Resume a paused flow run.

Source code in prefect/server/api/flow_runs.py
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
@router.post("/{id}/resume")
async def resume_flow_run(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    db: PrefectDBInterface = Depends(provide_database_interface),
    run_input: Optional[Dict] = Body(default=None, embed=True),
    response: Response = None,
    flow_policy: BaseOrchestrationPolicy = Depends(
        orchestration_dependencies.provide_flow_policy
    ),
    task_policy: BaseOrchestrationPolicy = Depends(
        orchestration_dependencies.provide_task_policy
    ),
    orchestration_parameters: Dict[str, Any] = Depends(
        orchestration_dependencies.provide_flow_orchestration_parameters
    ),
    api_version=Depends(dependencies.provide_request_api_version),
) -> OrchestrationResult:
    """
    Resume a paused flow run.
    """
    now = pendulum.now("UTC")

    async with db.session_context(begin_transaction=True) as session:
        flow_run = await models.flow_runs.read_flow_run(session, flow_run_id)
        state = flow_run.state

        if state is None or state.type != schemas.states.StateType.PAUSED:
            result = OrchestrationResult(
                state=None,
                status=schemas.responses.SetStateStatus.ABORT,
                details=schemas.responses.StateAbortDetails(
                    reason="Cannot resume a flow run that is not paused."
                ),
            )
            return result

        orchestration_parameters.update({"api-version": api_version})

        keyset = state.state_details.run_input_keyset

        if keyset:
            run_input = run_input or {}

            try:
                hydration_context = await schema_tools.HydrationContext.build(
                    session=session,
                    raise_on_error=True,
                    render_jinja=True,
                    render_workspace_variables=True,
                )
                run_input = schema_tools.hydrate(run_input, hydration_context) or {}
            except schema_tools.HydrationError as exc:
                return OrchestrationResult(
                    state=state,
                    status=schemas.responses.SetStateStatus.REJECT,
                    details=schemas.responses.StateAbortDetails(
                        reason=f"Error hydrating run input: {exc}",
                    ),
                )

            schema_json = await models.flow_run_input.read_flow_run_input(
                session=session, flow_run_id=flow_run.id, key=keyset["schema"]
            )

            if schema_json is None:
                return OrchestrationResult(
                    state=state,
                    status=schemas.responses.SetStateStatus.REJECT,
                    details=schemas.responses.StateAbortDetails(
                        reason="Run input schema not found."
                    ),
                )

            try:
                schema = orjson.loads(schema_json.value)
            except orjson.JSONDecodeError:
                return OrchestrationResult(
                    state=state,
                    status=schemas.responses.SetStateStatus.REJECT,
                    details=schemas.responses.StateAbortDetails(
                        reason="Run input schema is not valid JSON."
                    ),
                )

            try:
                schema_tools.validate(run_input, schema, raise_on_error=True)
            except schema_tools.ValidationError as exc:
                return OrchestrationResult(
                    state=state,
                    status=schemas.responses.SetStateStatus.REJECT,
                    details=schemas.responses.StateAbortDetails(
                        reason=f"Reason: {exc}"
                    ),
                )
            except schema_tools.CircularSchemaRefError:
                return OrchestrationResult(
                    state=state,
                    status=schemas.responses.SetStateStatus.REJECT,
                    details=schemas.responses.StateAbortDetails(
                        reason="Invalid schema: Unable to validate schema with circular references.",
                    ),
                )

        if state.state_details.pause_reschedule:
            orchestration_result = await models.flow_runs.set_flow_run_state(
                session=session,
                flow_run_id=flow_run_id,
                state=schemas.states.Scheduled(
                    name="Resuming", scheduled_time=pendulum.now("UTC")
                ),
                flow_policy=flow_policy,
                orchestration_parameters=orchestration_parameters,
            )
        else:
            orchestration_result = await models.flow_runs.set_flow_run_state(
                session=session,
                flow_run_id=flow_run_id,
                state=schemas.states.Running(),
                flow_policy=flow_policy,
                orchestration_parameters=orchestration_parameters,
            )

        if (
            keyset
            and run_input
            and orchestration_result.status == schemas.responses.SetStateStatus.ACCEPT
        ):
            # The state change is accepted, go ahead and store the validated
            # run input.
            await models.flow_run_input.create_flow_run_input(
                session=session,
                flow_run_input=schemas.core.FlowRunInput(
                    flow_run_id=flow_run_id,
                    key=keyset["response"],
                    value=orjson.dumps(run_input).decode("utf-8"),
                ),
            )

        # set the 201 if a new state was created
        if orchestration_result.state and orchestration_result.state.timestamp >= now:
            response.status_code = status.HTTP_201_CREATED
        else:
            response.status_code = status.HTTP_200_OK

        return orchestration_result

set_flow_run_state async

Set a flow run state, invoking any orchestration rules.

Source code in prefect/server/api/flow_runs.py
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
@router.post("/{id}/set_state")
async def set_flow_run_state(
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    state: schemas.actions.StateCreate = Body(..., description="The intended state."),
    force: bool = Body(
        False,
        description=(
            "If false, orchestration rules will be applied that may alter or prevent"
            " the state transition. If True, orchestration rules are not applied."
        ),
    ),
    db: PrefectDBInterface = Depends(provide_database_interface),
    response: Response = None,
    flow_policy: BaseOrchestrationPolicy = Depends(
        orchestration_dependencies.provide_flow_policy
    ),
    orchestration_parameters: Dict[str, Any] = Depends(
        orchestration_dependencies.provide_flow_orchestration_parameters
    ),
    api_version=Depends(dependencies.provide_request_api_version),
) -> OrchestrationResult:
    """Set a flow run state, invoking any orchestration rules."""

    # pass the request version to the orchestration engine to support compatibility code
    orchestration_parameters.update({"api-version": api_version})

    now = pendulum.now("UTC")

    # create the state
    async with db.session_context(
        begin_transaction=True, with_for_update=True
    ) as session:
        orchestration_result = await models.flow_runs.set_flow_run_state(
            session=session,
            flow_run_id=flow_run_id,
            # convert to a full State object
            state=schemas.states.State.parse_obj(state),
            force=force,
            flow_policy=flow_policy,
            orchestration_parameters=orchestration_parameters,
        )

    # set the 201 if a new state was created
    if orchestration_result.state and orchestration_result.state.timestamp >= now:
        response.status_code = status.HTTP_201_CREATED
    else:
        response.status_code = status.HTTP_200_OK

    return orchestration_result

update_flow_run async

Updates a flow run.

Source code in prefect/server/api/flow_runs.py
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
@router.patch("/{id}", status_code=status.HTTP_204_NO_CONTENT)
async def update_flow_run(
    flow_run: schemas.actions.FlowRunUpdate,
    flow_run_id: UUID = Path(..., description="The flow run id", alias="id"),
    db: PrefectDBInterface = Depends(provide_database_interface),
):
    """
    Updates a flow run.
    """
    async with db.session_context(begin_transaction=True) as session:
        if flow_run.job_variables is not None:
            this_run = await models.flow_runs.read_flow_run(
                session, flow_run_id=flow_run_id
            )
            if this_run is None:
                raise HTTPException(
                    status.HTTP_404_NOT_FOUND, detail="Flow run not found"
                )
            if not this_run.state:
                raise HTTPException(
                    status.HTTP_400_BAD_REQUEST,
                    detail="Flow run state is required to update job variables but none exists",
                )
            if this_run.state.type != schemas.states.StateType.SCHEDULED:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail=f"Job variables for a flow run in state {this_run.state.type.name} cannot be updated",
                )
            if this_run.deployment_id is None:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail="A deployment for the flow run could not be found",
                )

            deployment = await models.deployments.read_deployment(
                session=session, deployment_id=this_run.deployment_id
            )
            if deployment is None:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail="A deployment for the flow run could not be found",
                )

            await validate_job_variables_for_deployment_flow_run(
                session, deployment, flow_run
            )

        result = await models.flow_runs.update_flow_run(
            session=session, flow_run=flow_run, flow_run_id=flow_run_id
        )
    if not result:
        raise HTTPException(status.HTTP_404_NOT_FOUND, detail="Flow run not found")