screentinker/server/test/debug-throughput.test.js
ScreenTinker fa3ab44c20 feat(#146): /api/status.debug throughput counters (gauges -> gauges + work done)
The debug block exposed only gauges (buckets, quarantined, inFlight) — state, not work.
A real flapping Firestick reads as flap.buckets:36, quarantined:0, indistinguishable
from healthy. Add lightweight in-memory throughput counters (total + last-completed
rolling window) so the server tells the flapper/flood story itself.

- lib/rolling-counter.js: shared bounded scalar counter (total, curWindow, lastWindow,
  windowStart); rolls lazily on bump AND read (no timer), idle decays to 0.
  DEBUG_STATS_WINDOW_MS default 60000.
- flap-limiter: refused{Total,LastWindow} (every allow:false), quarantineStarts{Total,
  LastWindow} (a quarantine event stays visible after the gauge decays).
- ota-breaker: stats() rateBackoff{Total,LastWindow}.
- ota-download-guard: servedTotal/shedTotal alongside the per-window values.
- database: maintenance sweepsTotal (confirm the prune is firing, not stalled).
- routes/status: debug block gains ota_breaker + the new fields (aggregate-only, cheap).

Tests: rolling-counter window-roll + idle decay; each counter increments on the right
event; booted /api/status asserts the new fields present + numeric. Suite 285/285.
Fallout doc: observability section lists the fields + what each tells a soak-watcher.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-30 23:24:32 -05:00

74 lines
3.8 KiB
JavaScript

'use strict';
// #146 observability — throughput counters on /api/status.debug. The shared rolling
// counter + each subsystem's total/lastWindow increment on the right event.
const os = require('node:os');
const path = require('node:path');
const crypto = require('node:crypto');
process.env.DATA_DIR = path.join(os.tmpdir(), 'st-thru-' + crypto.randomBytes(4).toString('hex'));
const { test } = require('node:test');
const assert = require('node:assert/strict');
const { rollingCounter, bump, read } = require('../lib/rolling-counter');
const flap = require('../lib/flap-limiter');
const breaker = require('../lib/ota-breaker');
const guard = require('../lib/ota-download-guard');
const config = require('../config');
test('rolling-counter: total accrues; lastWindow = last CLOSED window; idle decays to 0', () => {
const c = rollingCounter(1000);
bump(c, 0); bump(c, 100); bump(c, 200); // window 1: 3 hits in [0,1000)
let r = read(c, 300);
assert.equal(r.total, 3);
assert.equal(r.lastWindow, 0, 'still inside window 1 — no completed window yet');
bump(c, 1100); // rolls: lastWindow=3, curWindow=1
r = read(c, 1200);
assert.equal(r.total, 4);
assert.equal(r.lastWindow, 3, 'lastWindow reflects window 1');
r = read(c, 6000); // 2+ idle windows
assert.equal(r.lastWindow, 0, 'no activity for 2+ windows -> lastWindow decays to 0');
});
test('flap: allow:false bumps refusedTotal; a quarantine start bumps quarantineStartsTotal', () => {
const save = { max: config.connectRateMax, win: config.connectRateWindowMs, cd: config.connectRateCooldownMs, qt: config.connectRateQuarantineTrips, qm: config.connectRateQuarantineMs };
Object.assign(config, { connectRateMax: 1, connectRateWindowMs: 100000, connectRateCooldownMs: 1, connectRateQuarantineTrips: 2, connectRateQuarantineMs: 100000 });
flap.reset();
try {
flap.check('d:t', 0); flap.check('d:t', 1); // 2nd exceeds max 1 -> trip1 (refused)
let s = flap.stats(2);
assert.ok(s.refusedTotal >= 1, 'a refusal bumped refusedTotal');
assert.equal(s.quarantineStartsTotal, 0, 'no quarantine yet');
flap.check('d:t', 3); flap.check('d:t', 4); // past cooldown -> trip2 -> quarantine
s = flap.stats(5);
assert.equal(s.quarantineStartsTotal, 1, 'quarantine start counted (even though the gauge later decays)');
assert.ok(s.refusedTotal >= 2, 'both refusals counted');
assert.equal(typeof s.refusedLastWindow, 'number');
} finally { Object.assign(config, { connectRateMax: save.max, connectRateWindowMs: save.win, connectRateCooldownMs: save.cd, connectRateQuarantineTrips: save.qt, connectRateQuarantineMs: save.qm }); flap.reset(); }
});
test('ota-breaker: a rate-backoff verdict bumps rateBackoffTotal', () => {
breaker.reset();
const before = breaker.stats(0).rateBackoffTotal;
for (let i = 0; i < 6; i++) breaker.decide('1.8.1', '1.9.2-beta7', null, i); // device=none flood > THRESHOLD
const s = breaker.stats(10);
assert.ok(s.rateBackoffTotal > before, `rate-backoff counted (${s.rateBackoffTotal})`);
assert.equal(typeof s.rateBackoffLastWindow, 'number');
});
test('ota-download: a shed bumps shedTotal; a serve bumps servedTotal', () => {
const s = guard.newState();
guard.admit(s, 'critical'); // shed
assert.equal(s.shedTotal, 1);
guard.admit(s, 'normal'); guard.admit(s, 'normal');
assert.equal(s.servedTotal, 2, 'serves counted');
});
test('maintenance: sweepsTotal increments per completed prune', async () => {
const { pruneStatusLog, getMaintenanceStats } = require('../db/database');
require('../lib/chunked-prune').__setBandForTest(() => 'normal');
const before = getMaintenanceStats().sweepsTotal;
await pruneStatusLog({ bandGate: false });
assert.equal(getMaintenanceStats().sweepsTotal, before + 1, 'a completed sweep bumped sweepsTotal');
});