Files
dify/api/tasks/dify_builder_advance_task.py
T
Charles YaoandClaude Opus 5.5 9323e60724 fix: give one worker exclusive lease ownership and settle terminal confirmed grants
Worker activation now swaps the dispatch token for a unique owner value, so a
duplicate delivery of a running command can neither run nor release the
winner's lease. Terminal worker failures clear pending confirmed references and
settle the worker's own reloaded grant; the sweeper repairs, in a bounded pass,
reserved grants whose command already reached review/FAILED but whose
settlement write failed, never while a lease is live.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-11 18:48:57 -07:00

543 lines
25 KiB
Python

"""Celery task that runs the dify_builder engine's ``Runner.advance`` off the
request thread (P3b Task 4).
The usecase's ``dispatch`` (Task 3) acquires the cross-process advance lock
(``services.dify_builder.session_lock``) in the web process and enqueues
this task; this task runs the actual engine step in the Celery process and
releases the lock in ``finally`` -- regardless of whether the step succeeded,
lost a version-CAS race, or raised. Progress (curated phase deltas,
native workflow events during test runs, plus the settled command projection) is
forwarded to the session's progress bus
(``services.dify_builder.progress_bus``) for the P3c SSE endpoint to relay.
Each invocation opens its own ``sessionmaker(bind=db.engine, ...)`` --
mirrors ``services.dify_builder.dify_port._session_factory`` -- rather
than reusing the Flask-request-scoped ``db.session``, since this runs in a
Celery worker, not a Flask request. The ``FlaskTask`` base
(``extensions.ext_celery.init_app``) already wraps the task body in
``app.app_context()``, so this module must NOT push its own context.
Once a message's user half is durable, a failed assistant half remains at
the current waiting gate. The client can then retry with the same
``client_turn_id`` without duplicating the user bubble.
A reserved confirmed Tool command (``CONFIRMED_TOOL_ACTION``) is reloaded from
the consent owner before any environment or agent setup; a forged, duplicate
or already launched delivery ends as a conflict without running anything.
"""
import logging
from collections.abc import Mapping
from dataclasses import asdict, replace
from celery import shared_task
from sqlalchemy.orm import sessionmaker
from configs import dify_config
from core.dify_builder.contract import (
AgentMessageEventData,
AssistantTurnItem,
ConversationItemAppendedEventData,
ExecutionActivity,
ExecutionProgress,
ProgressEventData,
ReasoningEventData,
WorkflowEventData,
post_canvas_action_id,
)
from core.dify_builder.errors import ConflictError
from core.dify_builder.execution_policy import BuilderExecutionPolicyError, ConfirmedToolExecutionContext
from core.dify_builder.handlers_build import build_registry
from core.dify_builder.handlers_edit import edit_registry
from core.dify_builder.handlers_fix import fix_registry
from core.dify_builder.models import CONFIRMED_TOOL_ACTION, Action, Actor, Session, Turn
from core.dify_builder.runner import Env, Runner
from core.dify_builder.state import PcState, is_terminal
from extensions.ext_database import db
from libs.datetime_utils import naive_utc_now
from services.dify_builder import app_naming, progress_bus, session_lock
from services.dify_builder.agent.localize import Localizer
from services.dify_builder.agent_factory import build_dify_builder_agent
from services.dify_builder.dify_port import WorkflowServiceDifyPort
from services.dify_builder.errors import HashMismatchError
from services.dify_builder.real_call_consent_service import BuilderRealCallConsentService
from services.dify_builder.repository import SqlDifyBuilderRepository
from services.dify_builder.revision import executable_graph_revision
from services.dify_builder.service import DifyBuilderService
logger = logging.getLogger(__name__)
__all__ = ["advance_session"]
_COMMAND_FINISHED_UNAVAILABLE_CODE = "command_finished_unavailable"
def _build_repo() -> SqlDifyBuilderRepository:
# Per-task sessionmaker (never the Flask-request-scoped db.session) --
# mirrors dify_port._session_factory().
return SqlDifyBuilderRepository(sessionmaker(bind=db.engine, expire_on_commit=False))
def _build_consent_service() -> BuilderRealCallConsentService:
return BuilderRealCallConsentService(sessionmaker(bind=db.engine, expire_on_commit=False))
def _require_reserved_launch(
repo: SqlDifyBuilderRepository, session_id: str, action: Action, actor: Actor
) -> ConfirmedToolExecutionContext:
"""Reload the server-reserved confirmed command before any environment or agent setup.
The queued payload is only a pointer: its consent reference must equal the
session's committed pending reference, and the consent owner must still
hold this exact command unlaunched for this actor/session. A forged,
serialized, duplicate or already launched delivery never runs.
"""
consent_id = action.payload.get("consent_id")
_session, fc = repo.get_session(session_id)
if (
set(action.payload) != {"consent_id"}
or not isinstance(consent_id, str)
or not consent_id
or (fc.confirmed_consent_id, fc.confirmed_command_id) != (consent_id, action.command_id)
):
logger.warning("dify_builder confirmed command not reserved (session=%s)", session_id)
raise ConflictError(f"dify_builder: confirmed command is not reserved for session {session_id}")
try:
return _build_consent_service().reserved_launch(
actor=actor, session_id=session_id, consent_id=consent_id, command_id=action.command_id
)
except BuilderExecutionPolicyError as error:
logger.warning(
"dify_builder confirmed command refused (session=%s, command=%s, reason=%s)",
session_id,
action.command_id,
error.reason_code,
)
raise ConflictError(f"dify_builder: confirmed command cannot launch for session {session_id}") from None
def _persist_failed_state(
repo: SqlDifyBuilderRepository,
session_id: str,
*,
expected_version: int,
expected_state: PcState,
command_id: str,
) -> int | None:
"""Persist a generic terminal failure even when agent construction failed."""
session, context = repo.get_session(session_id)
if is_terminal(session.current_state):
return None
if session.version != expected_version or session.current_state != expected_state:
raise ConflictError(
f"dify_builder: refusing stale setup failure for session {session_id} "
f"at version {session.version} state {session.current_state}"
)
at_version = session.version + 1
item = AssistantTurnItem(
turn_id=command_id,
stage_id=str(session.current_state),
execution=ExecutionProgress(status="error"),
reply_text="The operation could not be completed. Restart from the current draft to continue.",
).to_item(seq=context.next_seq, at_version=at_version)
context.next_seq += 1
context.last_command_id = command_id
# Terminal: a pending confirmed command reference never survives into a retry.
context.confirmed_consent_id = ""
context.confirmed_command_id = ""
return repo.compare_and_advance(session.id, session.version, PcState.FAILED, context, [item])
def _settle_reserved_grant(context: ConfirmedToolExecutionContext) -> None:
"""Close this worker's own reloaded grant from its durable record after a terminal failure.
The consent owner decides: failed/expired before any claim, unknown after
one unless a sealed completion exists; counters are never touched and a
final grant is left as is. A failed write is repaired by the sweeper.
"""
try:
_build_consent_service().settle_launch(context=context)
except Exception:
logger.warning(
"dify_builder confirmed grant settlement deferred to reconciliation (session=%s, command=%s)",
context.session_id,
context.command_id,
)
@shared_task(
queue="dify_builder",
soft_time_limit=dify_config.DIFY_BUILDER_MAX_ADVANCE_SECONDS,
time_limit=session_lock.active_advance_time_limit(),
)
def advance_session(session_id: str, action_dict: dict, actor_dict: dict, token: str) -> None:
"""Run one ``Runner.advance`` for ``session_id``, then release the
advance lock this worker activated from ``token``. Always releases its own
lock, even on a lost CAS race or an unexpected engine failure -- a stuck
lock would wedge the session for its full TTL
(``DIFY_BUILDER_MAX_ADVANCE_SECONDS``). A delivery that cannot activate the
token (stale, or a duplicate of a running command) neither runs nor releases."""
# Exactly one delivery owns the lease; a duplicate or stale delivery gets None and never
# runs or releases, so it cannot delete an active worker's lease.
owner = session_lock.activate(session_id, token)
if not owner:
logger.warning("dify_builder stale or duplicate queued advance ignored for session %s", session_id)
return
terminal_error: dict | None = None
completed: tuple[SqlDifyBuilderRepository, WorkflowServiceDifyPort, Actor] | None = None
repo: SqlDifyBuilderRepository | None = None
dify: WorkflowServiceDifyPort | None = None
actor: Actor | None = None
runner: Runner | None = None
env: Env | None = None
loaded_session: Session | None = None
last_progress: ProgressEventData | None = None
progress_activities: dict[str, ExecutionActivity] = {}
progress_operation_id = ""
action: Action | None = None
# Set only after this worker reloaded its own server-reserved confirmed command.
confirmed_context: ConfirmedToolExecutionContext | None = None
try:
repo = _build_repo()
dify = WorkflowServiceDifyPort()
actor = Actor(**actor_dict)
action = Action(**action_dict)
confirmed = action.kind == CONFIRMED_TOOL_ACTION
if confirmed:
confirmed_context = _require_reserved_launch(repo, session_id, action, actor)
# The per-session model choice lives on the context (stable for the session).
# Read the head so the real agent is constructed with the user's chosen model.
loaded_session, _fc = repo.get_session(session_id)
agent = build_dify_builder_agent(
tenant_id=actor.tenant_id, model_config=_fc.model_config, account_id=actor.account_id
)
def emit_workflow(payload: Mapping[str, object]) -> None:
assert env is not None
try:
progress_bus.publish(
session_id,
asdict(
WorkflowEventData(
session_id=session_id,
operation_id=env.operation_id,
stage_id=env.stage_id,
at_version=env.at_version,
revision=env.next_event_revision(),
payload=dict(payload),
)
),
)
except Exception:
logger.exception("dify_builder workflow event publish failed for session %s", session_id)
def emit_canvas(event: dict) -> None:
assert env is not None
try:
progress_bus.publish(
session_id,
{
"kind": "canvas",
"session_id": session_id,
"operation_id": env.operation_id,
"stage_id": env.stage_id,
"at_version": env.at_version,
"revision": env.next_event_revision(),
**event,
},
)
except Exception:
logger.exception("dify_builder canvas event publish failed for session %s", session_id)
def emit_message(message: AgentMessageEventData) -> None:
try:
progress_bus.publish(session_id, asdict(message))
except Exception:
# Streaming delivery is best effort. The terminal sequence
# watermark exposes the missing assistant item so the client
# can recover it through the history endpoint.
logger.exception(
"dify_builder agent_message event publish failed for session %s turn %s",
session_id,
message.turn_id,
)
def emit_item(event: ConversationItemAppendedEventData) -> None:
try:
progress_bus.publish(session_id, asdict(event))
except Exception:
# The terminal sequence watermark lets the client detect this
# missing item and recover it through the history endpoint.
logger.exception(
"dify_builder conversation item event publish failed for session %s seq %s",
session_id,
event.item.seq,
)
def emit_reasoning(reasoning: ReasoningEventData) -> None:
try:
progress_bus.publish(session_id, asdict(reasoning))
except Exception:
logger.exception(
"dify_builder reasoning event publish failed for session %s operation %s",
session_id,
reasoning.operation_id,
)
def emit_progress(progress: ProgressEventData) -> None:
nonlocal last_progress, progress_operation_id
if progress.operation_id != progress_operation_id:
progress_activities.clear()
progress_operation_id = progress.operation_id
if progress.activity is not None:
progress_activities[progress.activity.id] = replace(progress.activity)
last_progress = progress
try:
progress_bus.publish(session_id, asdict(progress))
except Exception:
# Phase progress is an observer notification. The following
# command_finished still carries the authoritative projection.
logger.exception(
"dify_builder progress event publish failed for session %s operation %s",
session_id,
progress.operation_id,
)
# `model_or_none` is part of the DifyBuilderAgent protocol; the Localizer
# uses it as its model provider (None -> reply-language localization is a no-op).
localizer = Localizer(agent.model_or_none)
def rename_app(proposed: str) -> str:
assert actor is not None
assert loaded_session is not None
return app_naming.rename_app_from_proposal(
app_id=loaded_session.app_id,
tenant_id=actor.tenant_id,
account_id=actor.account_id,
proposed=proposed,
)
env = Env(
dify=dify,
agent=agent,
repo=repo,
now=naive_utc_now,
emit_workflow=emit_workflow,
emit_canvas=emit_canvas,
emit_message=emit_message,
emit_item=emit_item,
emit_progress=emit_progress,
emit_reasoning=emit_reasoning,
# A confirmed outcome is deterministic status metadata: no model call.
detect_language=None if confirmed else localizer.detect_language,
localize_items=None if confirmed else localizer.localize_items,
rename_app=None if confirmed else rename_app,
command_id=action.command_id,
)
runner = Runner(env, fix_registry() | build_registry() | edit_registry())
if action.base_app_revision:
_graph, current_app_revision = dify.read_graph(loaded_session.app_id, actor)
if action.base_app_revision != current_app_revision:
raise ConflictError(f"stale app revision for app {loaded_session.app_id}")
runner.advance(session_id, Turn(action=action, actor=actor))
completed = (repo, dify, actor)
except (ConflictError, HashMismatchError):
terminal_error = {
"kind": "error",
"error": "conflict",
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
except Exception:
# Generic message only -- never leak exception detail into the
# progress event (it is relayed to the end user via SSE in P3c).
logger.exception("dify_builder advance failed for session %s", session_id)
if last_progress is not None and last_progress.status == "running":
active_activities = [activity for activity in progress_activities.values() if activity.state == "active"]
failure_deltas = [replace(activity, state="failed") for activity in active_activities] or [None]
try:
for revision_offset, activity in enumerate(failure_deltas, start=1):
progress_bus.publish(
session_id,
asdict(
replace(
last_progress,
revision=last_progress.revision + revision_offset,
status="error",
activity=activity,
)
),
)
except Exception:
logger.exception("dify_builder failed progress publish failed for session %s", session_id)
retryable_message_failure = False
failed_action_kind = action.kind if action is not None else action_dict.get("kind")
failed_action_payload = action.payload if action is not None else action_dict.get("payload")
if repo is not None and failed_action_kind == "message" and isinstance(failed_action_payload, dict):
client_turn_id = failed_action_payload.get("client_turn_id")
if isinstance(client_turn_id, str) and client_turn_id:
try:
turn_kinds = repo.get_conversation_turn_kinds(session_id, client_turn_id)
retryable_message_failure = "user" in turn_kinds and "assistant_turn" not in turn_kinds
except Exception:
logger.exception(
"dify_builder could not inspect failed message turn for session %s",
session_id,
)
if retryable_message_failure:
terminal_error = {
"kind": "error",
"error": "step failed",
"recoverable": True,
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
elif runner is not None:
try:
assert repo is not None
# ``Runner.fail`` normally fences with the operation metadata
# established by ``Runner.advance``. If a failure happens
# before that metadata is initialized, compare against the
# head loaded by this worker so an expired/stale worker cannot
# overwrite a transition committed by a newer one.
if env is not None and env.at_version <= 0 and loaded_session is not None:
current, _context = repo.get_session(session_id)
if (
current.version != loaded_session.version
or current.current_state != loaded_session.current_state
):
raise ConflictError(
f"dify_builder: refusing stale failure for session {session_id} "
f"at version {current.version} state {current.current_state}"
)
runner.fail(session_id)
assert dify is not None
assert actor is not None
completed = (repo, dify, actor)
except ConflictError:
logger.warning("dify_builder stale worker failure ignored for session %s", session_id)
terminal_error = {
"kind": "error",
"error": "conflict",
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
except Exception:
logger.exception("dify_builder could not persist failed state for session %s", session_id)
terminal_error = {
"kind": "error",
"error": "step failed",
"recoverable": True,
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
elif repo is not None and loaded_session is not None:
try:
_persist_failed_state(
repo,
session_id,
expected_version=loaded_session.version,
expected_state=loaded_session.current_state,
command_id=action.command_id if action is not None else str(action_dict.get("command_id") or ""),
)
if dify is not None and actor is not None:
completed = (repo, dify, actor)
else:
terminal_error = {
"kind": "error",
"error": "step failed",
"recoverable": True,
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
except ConflictError:
logger.warning("dify_builder stale setup failure ignored for session %s", session_id)
terminal_error = {
"kind": "error",
"error": "conflict",
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
except Exception:
logger.exception("dify_builder could not persist early failed state for session %s", session_id)
terminal_error = {
"kind": "error",
"error": "step failed",
"recoverable": True,
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
else:
terminal_error = {
"kind": "error",
"error": "step failed",
"recoverable": True,
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
}
if confirmed_context is not None:
# Terminal failure of this worker's own reserved command: settle its grant once
# (idempotent; a grant the port already settled is final and left as is).
_settle_reserved_grant(confirmed_context)
finally:
# Only this worker's owner value releases the activated lease.
session_lock.release(session_id, owner)
# Publish terminal frames only after releasing the lock so the
# authoritative SSE state no longer projects a completed/waiting
# transition as executing.
if terminal_error is not None:
progress_bus.publish(session_id, terminal_error)
elif completed is not None:
# The advance already succeeded and the lock is released; the session is
# durable. But the view projection (read_graph) or the publish itself can
# still raise -- and if this block let that escape, NO terminal frame
# would reach the SSE client, hanging its stream to the deadline with a
# stale held version (-> 409 on its next action). Fall back to a terminal
# error frame so the client stream always ends.
try:
repo, dify, actor = completed
def get_verification_identity(app_id: str, owner: Actor) -> tuple[str, str]:
graph, revision = dify.read_graph(app_id, owner)
return revision, executable_graph_revision(graph)
view = DifyBuilderService(
repo,
session_lock,
lambda *a, **k: None,
get_app_revision_fn=lambda app_id, owner: dify.read_graph(app_id, owner)[1],
get_verification_identity_fn=get_verification_identity,
).get_session_view(session_id, actor)
progress_bus.publish(
session_id,
{
"kind": "command_finished",
**asdict(view),
"command_id": action.command_id if action is not None else action_dict.get("command_id", ""),
"post_canvas_action_id": post_canvas_action_id(
str(loaded_session.current_state) if loaded_session is not None else None,
action.kind if action is not None else action_dict.get("kind"),
completed_state=view.state,
available_action_ids=[available.id for available in view.actions],
),
},
)
except Exception:
logger.exception("dify_builder command_finished projection/publish failed for session %s", session_id)
try:
progress_bus.publish(
session_id,
{
"kind": "error",
"code": _COMMAND_FINISHED_UNAVAILABLE_CODE,
"error": "step failed",
"session_id": session_id,
"command_id": action.command_id if action is not None else action_dict.get("command_id"),
},
)
except Exception:
logger.exception("dify_builder terminal error frame also failed to publish for session %s", session_id)