Every distinct 5-decimal point was a permanent in-memory entry, a
permanent line in an uncapped `.gev-cache/terrain-heights.json`, and a
live upstream call. Nothing limited the rate, and coordinates were
checked for being finite rather than for being on Earth, so an
out-of-range pair was still a valid cache key.
Four bounds, each following a pattern this repo already uses:
- WGS-84 range is enforced in `parseTerrainPoints`, at the edge, so no
later stage has to. Poles and the antimeridian still parse.
- The point cache holds at most 50,000 entries and evicts oldest-first,
the shape `trackBackfillProxies` uses. Sized from measurement: this
checkout's cache file held 6,189 entries in 1.0 MB of real use, so the
ceiling is eight times that working set. Terrain does not move, so an
evicted point costs one refetch and never a wrong answer.
- A cache file above 24 MB is not read back, mirroring
`rocketLaunchesProxy`. An unmeasurable file is not treated as an
oversized one: without stat, readFile decides, exactly as before.
- The route carries an always-on limiter of 90/min per client, 270
global — the `/api/overpass` band, and an order of magnitude above
measured demand (a full test:track run drove 10 requests, peak 8/min).
The ceilings are constructor options so they can be exercised as
behaviour rather than asserted as constants; production passes none.
They are destructured in the body because `proxyErrorResponses.test.mjs`
slices these proxies to the first column-zero closing brace.
Use 64-point browser and upstream terrain batches to reduce cold-cache timeouts. Preserve successful chunk results, distinguish absent readings from malformed responses, and reject fabricated zero heights.
Original terrain resilience contribution by ItzDESTAQ, with browser batching, validation and regression follow-up by Sameh Khamis.
Validated with unit/build/format/boundary checks, 108 tracking checks, 5 terrain-outage checks, controlled slow-upstream comparison and live browser checks.
Co-authored-by: ItzDESTAQ <[email protected]>
Co-authored-by: Sameh Khamis <[email protected]>
daikaginza