Files
meshcore-analyzer/docs/specs
efitenandClaude Opus 5.5 a08f2f4e7c fix(liveness): count only evidence that can be the node alone (#2260) (#2261)
Fixes #2260 (part 1 of 2: liveness; the adaptive offline threshold
follows in a separate PR).

## Problem

A repeater silent since 2026-10-18 showed **Active — Last relayed 4m
ago** and **Last Heard 36m**, and its offline mail never fired. Every
hit after that date was the 1-byte hop `67`, shared by nine nodes:

- the live resolver's affinity tiebreak (`resolvePathForObs`) put those
transmissions in `byNode`, which fed `stats.lastHeard` and
`LastHeardMap`;
- `last_relayed` folds in the 1-byte prefix bucket on purpose (#662),
and drove the status in `roles.js` and the notify offline check.

## Fix

The store keeps `certainHeard` per node: the newest transmission that
can only be that node.

| Evidence | Counts? |
|---|---|
| Own packet (`pubKey`, `srcPubKey`) | ✅ |
| Flood relay hop whose prefix, at the packet's path hash size, matches
exactly one path-capable node | ✅ |
| 1-byte hop shared with other repeaters | ❌ |
| Direct-route path (hops still to come, `Mesh::removeSelfFromPath`) | ❌
|
| TRACE (path bytes are SNR) | ❌ |
| Destination (`destPubKey`) | ❌ |

A multibyte repeater legitimately appears as a 1-byte hop (the
originator picks the hash size, `Mesh::routeRecvPacket` appends at that
size), so only uniqueness decides. The rule is applied in every load
path through `indexResolvedPathHops` and the new
`indexColdLoadRelayHops`: Load, loadChunk, scanAndMergeChunk, live
ingest, late observations.

Liveness reads only that:

- `/api/nodes` and the node detail: `last_heard` is the newer of
`last_seen` and the certain last heard. Before, it was a plain copy of
`last_seen`.
- health / bulk-health `stats.lastHeard`.
- `LastHeardMap` → notify offline check. The separate relay input
(`lastRelayed`, `relayTimes`, `notifyInput.Relayed`) is removed.
- `roles.js getEffectiveHeardMs`: newest known timestamp, without
`last_relayed`. The side pane no longer says "Last relayed"; the Last
Relayed row stays (analytics) with an updated tooltip.
- New status **`uncertain`** (repeaters and rooms): nothing certain
within the silent window, but the shared prefix (`last_relayed`) still
in paths. Grey badge with explanation, an *Uncertain* filter on the
nodes list and the map, dimmed like stale. The offline mail for such a
node says only its shared prefix was still seen.
- A prefix also held by a path-capable node in `inactive_nodes` is not
unique; adverts with `signatureValid: false` are no evidence;
`/api/nodes/search` reports the same `last_heard`.

Attribution for analytics (`byNode`, packet counts, `last_relayed`,
relay counters, usefulness) is unchanged.

## Performance

Hot path: `noteCertainRelays` runs per observation on ingest under the
write lock: two hex bytes of header parsing plus one prefix-map lookup
per resolved hop.

```
BenchmarkNoteCertainRelays-16   10307640   116.2 ns/op   0 B/op   0 allocs/op   (8-hop 2-byte path, 2,000 repeaters)
BenchmarkLastHeardMap-16            1902   0.77 ms/op                            (5,000 nodes; was 3.7 ms scanning byNode)
```

Memory: one string per node ever certainly heard, dropped together with
the node's `byNode` list on eviction.

## Tests

- `certain_heard_loadpaths_test.go`: every load path (Load, loadChunk,
LoadChunked — each with and without resolved_path — live ingest, late
observations) feeds `certainHeard`; each of the 8 call sites verified
red with a nil prefix map.
- `certain_heard_test.go`: hop width per route/payload type; retired
namesake prefix; failed signature; uncertain offline mail; shared vs
unique 1-byte vs 2-byte hops; direct/TRACE/nil prefix map; cold-load
path; sender vs destination; eviction; `lastHeardValue`; `/api/nodes`,
detail and health agree.
- Regression for #2260: last certain packet on day X, 20 shared-prefix
hops after it → `LastHeardMap` stays at X and `node.offline` goes bad
after 72 h. Verified red with the uniqueness check mutated out.
- Notify: `TestEvaluateCertainHeard` replaces the relay-input test.
- Frontend: `last_relayed` alone no longer keeps a repeater or room
active; newest timestamp wins (an old `_liveSeen` can't hide a fresh
certain relay).
- `cmd/server` `go test ./...` and `test-all.sh` pass locally, also on a
trial merge into a downstream fork with 457 extra commits.

## Validation

Ran the server on the freshened e2e fixture: list, detail and health
report the same last heard; e.g. a repeater whose `last_relayed` is 3
min newer than anything certain keeps its certain time. **No browser
screenshot**: Playwright isn't installed on this machine; CI's E2E
covers the pages.

## Not changed

- The ingestor's relay touch of `nodes.last_seen` (#1854) resolves a
shared hop only when exactly one candidate is adjacent in the neighbor
graph; it did not fire in this case. Left as is.
- The `lastHeard=` list filter still filters `last_seen` in SQL.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-22 19:11:30 +02:00
..