Each /weather/tiles request was running the full ScalarFile decode path
(File.read → gunzip → Msgpax.unpack → normalize) for any non-analysis
valid_time, because GridCache deliberately skipped forecast hours to keep
memory low. With 21 simultaneous viewport tiles all hitting the same few
chunk files, each tile took 1.5-3.2s of contended IO + CPU.
On a GridCache miss when a ScalarFile exists, hydrate GridCache from the
file once (deduped via the existing claim_fill primitive) and serve all
subsequent reads from ETS. Bound memory with prune_keep_latest/1 — keep
the 24 most-recently-touched valid_times, which covers a full HRRR run
(analysis + 18 forecasts) plus a few stragglers from the previous run.
In the steady state, the first viewport read for a given forecast hour
takes one full ScalarFile decode (~50-100 ms for 92k cells); every
subsequent tile, point lookup, and viewport read for the same hour
serves from ETS in <1 ms.
Band-warm failures in the Rust propagation_ready pipeline were only
surfaced via Logger.warning, so Prometheus had no way to see them.
The /weather GridCache hit/miss was likewise invisible while its
/map counterpart (ScoreCache) already reported cache ratio.
- NotifyListener emits [:microwaveprop, :propagation, :notify_listener, :warm]
with %{ok, err} measurements and %{valid_time} metadata after every
propagation_ready notification. Public handle_propagation_ready/1 so
tests can exercise the warm+telemetry path without Postgrex.
- GridCache.fetch/1, fetch_bounds/2, and fetch_point/3 emit
[:microwaveprop, :weather, :grid_cache, :lookup] with a :hit | :miss
metadata key on every ETS lookup.
1. GridCache: auto-release fill lock when the claimer process crashes.
claim_fill/1 + release_fill/1 go through the GenServer so the
server can Process.monitor the caller and clean up the ETS entry
on :DOWN. Clear/0 now resets both the data table and the lock
table. Fixes a latent bug where a crashed fill leaked the lock
indefinitely, preventing every subsequent /weather mount for that
valid_time from claiming and leaving cache cold.
2. RadarFrameWorker: distinguish permanent vs transient fetch errors.
404 from the IEM n0q archive is permanent (file will never exist)
and marks contacts :unavailable as before. Any other error shape
(5xx, timeout, transport failure) now returns {:error, reason}
so Oban retries — previously those also pinned contacts at
:unavailable after a transient outage.
3. AdminTaskWorker.native_derive: replace per-row Repo.update_all
(N round-trips + N fsyncs) with one UPDATE ... FROM unnest(...)
per 2000-row batch. For the 10k-profile budget this is one
network round trip per chunk instead of 10k, and one fsync per
chunk instead of 10k. Restructured the clause to separate
derivation (pure) from persistence (I/O).
All three changes are test-covered (grid_cache_test auto-release
test, radar_frame_worker_test 5xx + transport tests, existing
admin_task_worker_test native_derive coverage exercises the new
bulk path). Also drops the scorer_diff no-op test that was
verifying the clause removed in 61da51c.
- Add Weather.GridCache: ETS cache of derived HRRR grid rows keyed by
valid_time, cluster-synced via PubSub. Eagerly warmed from
PropagationGridWorker after each upsert so /weather map pan/zoom and
weather_point_detail hit zero DB on warm cache.
- Replace latest_weather_grid DB query path with cache-first lookup +
DB fallback. hrrr_profiles is 42M rows partitioned; pulling 3-10k
rows per viewport on every pan was the main cost.
- ContactLive.Show: defer the heavy enrichment loads (weather, solar,
HRRR, terrain, IEMRE, elevation profile, ITU-R propagation analysis,
data_sources) into a handle_info(:hydrate) that runs after the shell
renders. Initial mount now returns nil placeholders; template already
had :if guards for all of them. Shell-to-first-paint goes from
~500ms-2s down to ~20ms.
- Cache fetch_queue_counts for 5s in ContactLive.Show — oban_jobs group
by query was running on every contact page view.
- Backfill stats: wrap count_unprocessed, fetch_stats, fetch_db_stats
in Microwaveprop.Cache with 2-5s TTLs; bump refresh debounce from 1s
to 2s so bulk enrichment events don't thrash the DB.
