RED commit `a2879e12` — perf regression test; CI run: see Actions tab.
Fixes#1257.
## Root cause
`handleNodes` looped over the response page and called
`store.GetRepeaterRelayInfo(pk, win)` +
`store.GetRepeaterUsefulnessScore(pk)` for every repeater/room. Each
call:
- grabbed its own `s.mu.RLock`,
- walked `byPathHop[pk]` (+ the matching 1-byte raw-prefix bucket, which
on busy networks fans out to nearly the entire non-advert tx set),
- and re-parsed every `tx.FirstSeen` with `parseRelayTS`.
Default page is the 50 most-recently-seen nodes — almost all hot
repeaters — so the request did O(50) lock acquisitions and hundreds of
thousands of timestamp parses on the same set of txs. That's the classic
load-then-paginate / per-row N+1 shape called out in the issue (same
family as #1226).
The `?limit=2000` variant looks faster relatively only because per-node
enrichment dwarfs serialization; on staging both still bottleneck on the
same loop.
## Fix
Two new bulk methods on `PacketStore`:
- `GetRepeaterRelayInfoMap(windowHours)` → `pubkey → RepeaterRelayInfo`
- `GetRepeaterUsefulnessScoreMap()` → `pubkey → 0..1`
Both snapshot `byPathHop` under a single `RLock`, pre-parse each
`FirstSeen` exactly once (a tx that appears in N hop buckets used to be
parsed N times), and emit one entry per hop key. Cached 15s — same TTL
as `GetNodeHashSizeInfo` / `GetMultiByteCapMap`, same status-column
freshness budget.
`handleNodes` is one map-lookup per node; behavior, output schema, and
`RelayActive` / `RelayCount{1h,24h}` / `LastRelayed` /
`usefulness_score` semantics are preserved.
## Why no `limit` default change
The issue mentioned a default-limit knob. Investigated: `queryInt(r,
"limit", 50)` already defaults to 50 — frontends calling `/api/nodes`
(no limit) get a 50-row page today. Capping further would change
behavior (live.js already passes `?limit=2000` when it wants more); the
cost was per-repeater enrichment, not page size. Fixing the N+1 is the
correct lever and preserves backward compat.
## Perf
Regression test `TestHandleNodesPerfLargeFleet` (600 nodes, 150k
non-advert tx, repeaters indexed under `byPathHop`):
| | elapsed | vs 2s budget |
|---|---|---|
| before (master) | 4.72s | ✗ |
| after | ~4ms | ✓ (~1000×) |
## TDD
- RED: `a2879e12` — test fails at 4.72s on master.
- GREEN: `c529d29a` — fix; full `cmd/server` + `cmd/ingestor` suites
green.
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Co-authored-by: corescope-bot <bot@corescope>
Kpa-clawbot