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fix(workflow): make background execution failures graceful #2065

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c2290a9
fix(workflow): make background execution failures graceful
daryllimyt Feb 10, 2026
d579109
test(auth): align auth dependency expectations with current behavior
daryllimyt Feb 10, 2026
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144 changes: 135 additions & 9 deletions tests/unit/test_workflow_executions.py
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@

"""

import asyncio
import datetime
from typing import Any, cast
from unittest.mock import AsyncMock, Mock, patch
Expand Down Expand Up @@ -148,6 +149,19 @@ def create_mock_history_event(
return event


def create_test_dsl_input() -> DSLInput:
"""Create a minimal valid DSLInput for tests."""
return DSLInput.model_validate(
{
"title": "Webhook test workflow",
"description": "Test workflow",
"entrypoint": {"ref": "start"},
"actions": [{"ref": "start", "action": "core.noop"}],
"config": {"enable_runtime_tests": False},
}
)


@pytest.mark.anyio
class TestWorkflowExecutionEvents:
"""Test workflow execution events functionality."""
Expand Down Expand Up @@ -903,15 +917,7 @@ async def test_create_workflow_execution_wait_for_start_acknowledges_temporal_st
service = WorkflowExecutionsService(client=mock_client, role=mock_role)
mock_client.start_workflow = AsyncMock(return_value=Mock(spec=WorkflowHandle))

dsl = DSLInput.model_validate(
{
"title": "Webhook test workflow",
"description": "Test workflow",
"entrypoint": {"ref": "start"},
"actions": [{"ref": "start", "action": "core.noop"}],
"config": {"enable_runtime_tests": False},
}
)
dsl = create_test_dsl_input()
wf_id = WorkflowUUID.new("wf_4itKqkgCZrLhgYiq5L211X")

with patch.object(
Expand All @@ -932,3 +938,123 @@ async def test_create_workflow_execution_wait_for_start_acknowledges_temporal_st
assert (
mock_client.start_workflow.await_args.kwargs["id"] == response["wf_exec_id"]
)


class TestWorkflowNowaitBackgroundBehavior:
@pytest.mark.anyio
async def test_create_workflow_execution_nowait_schedules_start_only(
self,
mock_client: Mock,
mock_role: Role,
) -> None:
service = WorkflowExecutionsService(client=mock_client, role=mock_role)
dsl = create_test_dsl_input()
wf_id = WorkflowUUID.new("wf_5K8NL5TYLRM8JqkDnGzYdE")

mock_wait_for_start = AsyncMock(
return_value={
"message": "Workflow execution started",
"wf_id": wf_id,
"wf_exec_id": "unused",
}
)
mock_wait_for_completion = AsyncMock()

with (
patch.object(
service,
"create_workflow_execution_wait_for_start",
mock_wait_for_start,
),
patch.object(
service,
"create_workflow_execution",
mock_wait_for_completion,
),
):
response = service.create_workflow_execution_nowait(
dsl=dsl,
wf_id=wf_id,
payload=None,
trigger_type=TriggerType.MANUAL,
)
await asyncio.sleep(0)

mock_wait_for_start.assert_awaited_once()
mock_wait_for_completion.assert_not_called()
assert mock_wait_for_start.await_args is not None
assert response["wf_exec_id"] == mock_wait_for_start.await_args.kwargs["wf_exec_id"]

@pytest.mark.anyio
async def test_create_draft_workflow_execution_nowait_schedules_start_only(
self,
mock_client: Mock,
mock_role: Role,
) -> None:
service = WorkflowExecutionsService(client=mock_client, role=mock_role)
dsl = create_test_dsl_input()
wf_id = WorkflowUUID.new("wf_4fHecX13GwQY74HCAS4j7L")

mock_wait_for_start = AsyncMock(
return_value={
"message": "Draft workflow execution started",
"wf_id": wf_id,
"wf_exec_id": "unused",
}
)
mock_wait_for_completion = AsyncMock()

with (
patch.object(
service,
"create_draft_workflow_execution_wait_for_start",
mock_wait_for_start,
),
patch.object(
service,
"create_draft_workflow_execution",
mock_wait_for_completion,
),
):
response = service.create_draft_workflow_execution_nowait(
dsl=dsl,
wf_id=wf_id,
payload=None,
trigger_type=TriggerType.MANUAL,
)
await asyncio.sleep(0)

mock_wait_for_start.assert_awaited_once()
mock_wait_for_completion.assert_not_called()
assert mock_wait_for_start.await_args is not None
assert response["wf_exec_id"] == mock_wait_for_start.await_args.kwargs["wf_exec_id"]

@pytest.mark.anyio
async def test_background_start_swallows_exceptions(
self,
mock_client: Mock,
mock_role: Role,
) -> None:
service = WorkflowExecutionsService(client=mock_client, role=mock_role)
dsl = create_test_dsl_input()
wf_id = WorkflowUUID.new("wf_5eP17nM2Cc7Bf1tBwNRar9")

mock_wait_for_start = AsyncMock(side_effect=RuntimeError("boom"))
with (
patch.object(
service,
"create_workflow_execution_wait_for_start",
mock_wait_for_start,
),
patch.object(service.logger, "error") as mock_error,
):
_ = service.create_workflow_execution_nowait(
dsl=dsl,
wf_id=wf_id,
payload=None,
trigger_type=TriggerType.MANUAL,
)
await asyncio.sleep(0)

mock_wait_for_start.assert_awaited_once()
mock_error.assert_called_once()
73 changes: 69 additions & 4 deletions tracecat/workflow/executions/service.py
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Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,71 @@ def _handle_background_task_exception(self, task: asyncio.Task[Any]) -> None:
exception=str(exc),
)

async def _start_workflow_execution_background(
self,
dsl: DSLInput,
*,
wf_id: WorkflowID,
wf_exec_id: WorkflowExecutionID,
payload: TriggerInputs | None = None,
trigger_type: TriggerType = TriggerType.MANUAL,
time_anchor: datetime.datetime | None = None,
registry_lock: RegistryLock | None = None,
memo: dict[str, Any] | None = None,
) -> None:
"""Start a published workflow in the background and swallow start errors.

Background dispatches should never bubble exceptions back to the event loop.
"""
try:
await self.create_workflow_execution_wait_for_start(
dsl=dsl,
wf_id=wf_id,
payload=payload,
trigger_type=trigger_type,
wf_exec_id=wf_exec_id,
time_anchor=time_anchor,
registry_lock=registry_lock,
memo=memo,
)
except Exception as e:
self.logger.error(
"Failed to start background workflow execution",
role=self.role,
wf_exec_id=wf_exec_id,
error=str(e),
)

async def _start_draft_workflow_execution_background(
self,
dsl: DSLInput,
*,
wf_id: WorkflowID,
wf_exec_id: WorkflowExecutionID,
payload: TriggerInputs | None = None,
trigger_type: TriggerType = TriggerType.MANUAL,
time_anchor: datetime.datetime | None = None,
registry_lock: RegistryLock | None = None,
) -> None:
"""Start a draft workflow in the background and swallow start errors."""
try:
await self.create_draft_workflow_execution_wait_for_start(
dsl=dsl,
wf_id=wf_id,
payload=payload,
trigger_type=trigger_type,
wf_exec_id=wf_exec_id,
time_anchor=time_anchor,
registry_lock=registry_lock,
)
except Exception as e:
self.logger.error(
"Failed to start background draft workflow execution",
role=self.role,
wf_exec_id=wf_exec_id,
error=str(e),
)

def handle(
self, wf_exec_id: WorkflowExecutionID
) -> WorkflowHandle[DSLWorkflow, StoredObject]:
Expand Down Expand Up @@ -700,14 +765,14 @@ def create_workflow_execution_nowait(
) -> WorkflowExecutionCreateResponse:
"""Create a new workflow execution.

Note: This method schedules the workflow execution and returns immediately.
Note: This method schedules the workflow start and returns immediately.

Args:
memo: Optional memo dict to store with the workflow execution.
Useful for correlation (e.g., parent_wf_exec_id).
"""
wf_exec_id = generate_exec_id(wf_id)
coro = self.create_workflow_execution(
coro = self._start_workflow_execution_background(
dsl=dsl,
wf_id=wf_id,
payload=payload,
Expand Down Expand Up @@ -773,10 +838,10 @@ def create_draft_workflow_execution_nowait(
"""Create a new draft workflow execution.

Draft executions use the draft workflow graph and resolve aliases from draft workflows.
This method schedules the workflow execution and returns immediately.
This method schedules workflow start and returns immediately.
"""
wf_exec_id = generate_exec_id(wf_id)
coro = self.create_draft_workflow_execution(
coro = self._start_draft_workflow_execution_background(
dsl=dsl,
wf_id=wf_id,
payload=payload,
Expand Down
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