Deploys (docker SIGTERM→SIGKILL, default 10s) were killing Celery jobs
mid-flight. Give in-flight work room to drain and make interrupted work
resume cleanly instead of stalling.
- docker-compose.yml: stop_grace_period per lane (web 30s / worker 90s /
scheduler 60s / maintenance-long 180s / ml-worker 120s) so warm shutdown
can actually drain before SIGKILL.
- celery_app.py: task_reject_on_worker_lost=True — a task killed past the
grace window is re-queued (safe: idempotent + chunked, recovery sweeps
re-drive stragglers).
- interpreter_client.py: map 429/5xx (502/503/504) → InterpreterUnavailable
and parse Retry-After (delta-seconds or HTTP-date); a draining Interpreter
behind a reverse proxy no longer raises an opaque HTTPError.
- translation.py: thread retry_after out of _translate_batch; retranslate_posts
resumes after the Retry-After hint (or 60s default, capped 900s) on an
interrupt with _reset_done=True, self-terminating via the health gate.
- tests: 429/5xx mapping + Retry-After parse; interrupt-resume + default backoff.
No migration.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
bvandeusen
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