IEM's ASOS CSV endpoint accepts multiple station= params in a single
request. Prior code enqueued one WeatherFetchWorker job per nearby
station per QSO endpoint — N jobs × 1 station each — which paid the
IemRateLimiter's 1500ms gap and the IEM 429-retry tail N times per
contact.
Changes:
- IemClient.asos_url/3 accepts a list of station codes.
- IemClient.fetch_asos_batch/3 fetches N stations in one call and
returns rows grouped by station_code (with absent codes filled as
empty lists so callers can stub them).
- parse_asos_csv/1 now exposes the station_code column it was
previously discarding.
- WeatherFetchWorker gains an "asos_batch" fetch_type clause that
unpacks rows per (station_id, station_code), upserting or stubbing
each. The single-station "asos" clause stays for already-queued
retryable jobs.
- ContactWeatherEnqueueWorker.build_asos_jobs/3 now emits one batch
job per (lat, lon, 4h window) covering every uncovered nearby
station (sorted for deterministic unique-args).
Expected effect on backfill: ~10-20x fewer IEM requests per contact
enrichment cycle, matching drop in 429 retry traffic.
When ASOS/RAOB/IEMRE APIs return empty data, store a stub record so
dedup checks (has_surface_observations?, has_sounding?, has_iemre_observation?)
see coverage and don't recreate the same jobs on future backfill runs.
- Add precip_1h_in and wx_codes fields to ASOS surface observations
- Add IEMRE reanalysis schema for radar-derived hourly precipitation
- Add IemreFetchWorker with exponential backoff and idempotency
- Integrate IEMRE enqueue into cron weather backfill pipeline
- All existing QSOs marked iemre_queued=false for automatic backfill
IEM was returning 503s under 10 concurrent workers. Three fixes:
- Req transient retry with exponential backoff on IEM requests
- WeatherFetchWorker Oban job retries failed ASOS/RAOB fetches 2-3h later
with random jitter to avoid thundering herd
- Import script concurrency reduced 10→5, weather queue capped at 3
