* fix(runs): cancel degrades to lease takeover for multi-worker
Work item 4 of the multi-worker ownership epic
(https://github.com/bytedance/deer-flow/issues/3948).
Problem: POST /runs/{run_id}/cancel landing on a non-owning worker
returns 409 — the cancel button silently fails under GATEWAY_WORKERS>1
with no sticky routing. cancel() required the current worker to hold
the in-memory task/abort_event, which any non-owner pod cannot satisfy.
Changes:
- RunManager.cancel() returns CancelOutcome enum (cancelled /
taken_over / lease_valid_elsewhere / not_active_locally /
not_cancellable / unknown) instead of bool, so the router can map
each outcome to the right HTTP response.
- New store primitive claim_for_takeover(): a single atomic
conditional UPDATE that marks a run as error only when
status IN (pending, running) AND (lease IS NULL OR
lease < now - grace). Closes the stale-read / concurrent-heartbeat
race — if the owner renews between our read and write, the UPDATE
matches 0 rows and we surface lease_valid_elsewhere.
- HTTP cancel + stream-join endpoints route on CancelOutcome:
cancelled -> 202 (or 204 with wait=true); taken_over -> 202
immediately (no SSE streaming — the run is terminal on another
worker, streaming would hang); lease_valid_elsewhere -> 409 +
Retry-After header computed from lease_expires_at + grace_seconds.
- RunManager.grace_seconds exposed as a public property; the router
no longer reaches into _run_ownership_config.
- _is_lease_expired extracted to a module-level function, shared by
RunManager.cancel() and MemoryRunStore.claim_for_takeover().
- GATEWAY_WORKERS=1 + heartbeat_enabled=false is zero-regression:
the non-local path short-circuits to not_active_locally, preserving
the original 409 behaviour the existing tests pin.
Tests: 12 new (5 store primitive + 4 cancel-takeover unit + 3 HTTP
including a regression guard verifying POST /stream?action=interrupt
on a dead-owner run returns 202 instead of hanging on SSE).
244 directly-related tests pass; 36/36 blocking-IO gate pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* fix(runs): guard update_status and self-terminate on takeover
Two defenses close a split-brain window where the original owner
could overwrite a peer's takeover status:
- update_status (SQL + memory store) now guards on
status IN ('pending','running'). When takeover already set
the row to 'error', the owner's final status write matches
0 rows and is dropped.
- _persist_status: when update_status returns False, check
whether the row exists before attempting recovery via put().
If the row exists (takeover by another worker), skip recovery
instead of blindly upserting over the takeover.
- Heartbeat _renew_leases: when update_lease returns False
(row no longer pending/running or owner changed), cancel the
local task so wasted CPU is bounded to the next heartbeat
tick (~10s) instead of the full task lifetime.
Also fix three reviewer feedback items:
- Re-fetch the store row when cancel() returns
lease_valid_elsewhere, so Retry-After uses the owner's
freshly-renewed lease instead of a stale value from
request start.
- Fallback 'unknown' in takeover error message when
owner_worker_id is NULL (pre-ownership data).
- Remove dead else-10 branch from grace_seconds property
(unreachable — all callers are downstream of the
heartbeat_enabled guard).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* test(runs): pin split-brain defences from update_status guard + heartbeat
Three tests lock down the takeover authoritativeness so a
late-running owner cannot overwrite a peer's claim:
- update_status must reject writes when the store row is already
terminal (taken over by another worker).
- _persist_status must skip row-recovery via put() when the row
exists but has been taken over.
- Heartbeat _renew_leases must cancel the local task when
update_lease returns False (row claimed by another worker).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* fix(runs): precise outcome + log when local cancel loses to peer takeover
Two reviewer precision nits on the split-brain defence:
- _persist_status: branch the skip-reason log on existing["status"].
error → WARNING "peer takeover" (anomalous); interrupted/success →
INFO "local cancel/completion race" (expected when user hits stop
as the run finishes). Stops noisy false-positive takeover warnings
in operator logs.
- cancel() local path: when _persist_status returns False, re-check
the store. If a peer's claim_for_takeover flipped the row to error
between our in-memory cancel and the guarded update_status, surface
taken_over instead of cancelled so the client sees a status
consistent with the store.
Test: test_cancel_returns_taken_over_when_peer_claims_during_local_cancel
pins the race outcome.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* fix(runs): widen update_status guard, de-duplicate lease helpers, add coverage
Round 3 of reviewer feedback:
- Widen update_status guard to status IN ('pending','running','interrupted').
The original guard blocked interrupted→error (the rollback finalize path),
losing the "Rolled back by user" message. interrupted is now permitted
while error/success stay locked — takeover protection unchanged.
- claim_for_takeover False now re-reads the store row to distinguish causes:
owner renewed lease → lease_valid_elsewhere; row went terminal →
not_cancellable; another worker already took it over → taken_over.
- Extract _raise_lease_valid_elsewhere() helper to de-duplicate the
409+Retry-After block shared across cancel_run and stream_existing_run.
- Extract _lease_expired_or_null() in persistence/run/sql.py to
de-duplicate the lease-expiry SQL WHERE clause shared by
claim_for_takeover and list_inflight_with_expired_lease.
- 11 new tests: 5 SQL-layer claim_for_takeover (expired/valid/NULL/
terminal/nonexistent), 3 _compute_retry_after unit (NULL/unparseable/
normal), 2 claim re-read precision (terminal/takeover), 1 stream
endpoint 409+Retry-After.
Not addressed (non-blocking, reviewer agreed):
- The 2–3 store.gets in the takeover cold path: optimizing the API to
accept a pre-fetched record would couple the router to the manager
more tightly than justified by the perf gain.
- The lease-expiry inline loop in MemoryRunStore.list_inflight_with_-
expired_lease pre-computes cutoff once for all rows; switching to the
shared _is_lease_expired helper would recompute datetime.now() per row
with no real benefit.
260 related tests pass; 36/36 blocking-IO gate pass; ruff clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* fix(runs): de-duplicate lease-expiry helper, restore defensive fallback
Address final round of review feedback:
- Extract is_lease_expired to deerflow.utils.time (no _ prefix, public
utility). Manager and MemoryRunStore now import from the same place
instead of the store reaching backward into the manager for a private
function.
- Restore defensive else-10 fallback in grace_seconds property (removed
in an earlier round). The guard is unreachable for current callers but
protects future ones from AttributeError.
- Comment the transient in-memory interrupted vs store error state when
a local cancel is superseded by a peer takeover.
- Comment the max(1, ...) floor in _compute_retry_after — the floor is
a lower bound, not a poll interval; clients should apply jitter.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
Co-authored-by: rayhpeng <rayhpeng@gmail.com>
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