Migrate the ingester queue storage from raw aiosqlite to SQLAlchemy Core
async. The backend is chosen by ingester.queue.dburi: a SQLAlchemy async
URL points the queue at a database server, and SQLite remains the default
when unset. The Postgres path claims jobs with FOR UPDATE SKIP LOCKED so
multiple ingester processes can share one queue; SQLite caps the pool to a
single connection to keep the select-then-update claim atomic.
Large files buffered entirely in RAM can OOM workers. Add
max_file_size to source config (default None = no limit).
FS checks stat().st_size before read_bytes(). HTTP and WebDAV issue
a HEAD request before GET when a limit is configured. S3 checks the
size from the existing head_async() call before get_async().
FileTooLargeError is classified as PermanentError so oversized files
go straight to the DLQ instead of retrying.
Workers parked on job_available.wait() were not woken by stop(),
causing them to sleep out the full poll_idle_interval_s before
noticing _stop. With the default 1.0s interval, stop() took ~0.8s
instead of ~0.007s.
Notify all waiters on the condition in stop() so idle workers exit
immediately. Add tests for fast job pickup via notification and
fast shutdown with idle workers.
If sync.upsert() or sync.delete() raises after a job is already
marked succeeded (e.g. disk full, DB locked), the unhandled
exception crashes the worker. The job stays succeeded but sync_state
is stale, and the crashed worker stops processing other jobs.
Wrap the post-success sync_state writes in a try/except. On failure,
log the error and continue. The worst case is a redundant re-ingest
on the next sweep — better than killing the worker.
