Graham McIntire
bbf6481603
Telemetry puts nexrad_decode_png at 1.76 s/call × 37,847 calls/h — ~18.5 h of CPU across the cluster every real hour, the single biggest CPU consumer in the system. The map-click path (fetch_rain_cells) already cached decoded frames by 5-min bucket, but the per-contact CommonVolumeRadarWorker path (fetch_decoded_frame) went straight to network + decode on every call. Backfill means many contacts share a 5-min window, so the same 66 MB frame was being decoded dozens of times. Wire fetch_decoded_frame through NexradCache keyed on the rounded timestamp. Add a 20-entry size cap in NexradCache so backfill processing contacts in random timestamp order can't grow the ETS table to hundreds of GB. Each frame is ~66 MB, so 20 = ~1.3 GB worst case, well under typical pod memory. Expected impact: cuts sustained decode load by an order of magnitude depending on backfill temporal locality; map-click path is unchanged. |
||
|---|---|---|
| .. | ||
| microwaveprop | ||
| microwaveprop_web | ||
| mix/tasks | ||
| microwaveprop.ex | ||
| microwaveprop_web.ex | ||