Backfill downloads stranded with empty logs + a generic "stranded by
recovery sweep" error. Root cause: the backfill gallery-dl subprocess
timeout (1170s) exceeded download_source's Celery soft_time_limit (900s),
so SoftTimeLimitExceeded preempted subprocess.TimeoutExpired. The
TimeoutExpired path (which captures partial stdout/stderr and finalizes
the event) never ran, the event was left 'running', and phase 3 never
decremented backfill_runs_remaining — so the source re-ran and
re-stranded every tick (Anduo #39912).
Two layers:
1. Raise download_source limits (soft 900→1350, hard 1200→1500) so both
subprocess budgets (870 tick / 1170 backfill) sit below the soft
limit with phase-3 persist headroom. Promote to module constants and
guard the invariant with a test.
2. Catch SoftTimeLimitExceeded in download_source and finalize the
in-flight event with a real reason, mirror phase-3 source-health, and
decrement backfill so a chronically-slow source self-heals to tick
mode. The existing celery_signals handler only covered TaskRun, not
DownloadEvent — that was the gap.
Updates stale 900/1200 references in gallery_dl.py + maintenance.py.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The `select(ImportSettings).where(id == 1)).scalar_one()` singleton load was
repeated 15× across services, API, and 5 task modules. Added async load() +
sync load_sync() classmethods on the model and migrated all 15 full-row sites
(callers already imported ImportSettings, so no new imports; dropped download's
now-orphaned select import). Left maintenance.py's deliberate column-select
(import_scan_path only) as-is.
Rest of the service layer was already adequately DRY — the Record/to_dict
pattern is only 2 instances and the savepoint find-or-create recovery is
correctly per-entity, so neither was forced into a shared abstraction.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
download/migration/scan each defined an identical _async_session_factory()
(fresh per-invocation async engine — async connections are event-loop-bound
so each asyncio.run() task needs its own engine, unlike the process-wide
_sync_engine). Moved it to tasks/_async_session.py; the 3 files import it
and drop their now-orphaned sqlalchemy.ext.asyncio / get_config imports
(migration keeps AsyncSession for a type hint). Call-site try/finally
dispose left as-is to avoid re-indenting the critical task bodies.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>