The subprocess-booting test suites hand-picked fixed ports in a cramped ~3955-4021 range, and
156-schedule-read-path deviated to a RANDOM port (3900 + rand%90) that overlapped those fixed
ports. Under CI load two servers could race on the same port, surfacing as flaky "no such table:
devices" / "FOREIGN KEY constraint failed" (a server answering a request against a half-migrated
or wrong DB). It's environmental — the suites pass locally and in isolation.
Fix: a shared test/helpers/free-port.js (bind :0 on loopback, read the OS-assigned port, release)
called in before() so every suite gets a guaranteed-unique ephemeral port — concurrent suites can
no longer collide, and no one has to hand-assign ports.
- Codemod converted 30 suites: const PORT = <fixed|random> -> let PORT (+ BASE) assigned via
`PORT = await freePort()` at the top of before().
- 3 hand-fixed (different structure): 148-eviction-storm (lowercase `base`), boot-health (no
before() — allocates PORT + a throwaway SEED_PORT inside the test, replacing the hardcoded
3894), totp-keyrotation (no before() — allocates at the test start before bootServer()).
No fixed 39xx/40xx ports remain. Full server suite 435/435; the 4 hand-touched suites pass in
isolation. Pure test-infra change — no app code touched.
1. devices_connected (always on, never gated): a top-level /api/status field next to
loop_lag = LIVE WS socket count from the heartbeat connection map (getConnectedCount),
NOT devices.status='online' (which lags by the offline-timeout). The single
most-glanced operational number, so it can't disappear when debug is off. Also dropped
4 dead per-poll COUNT(*) queries the route computed but never returned.
2. debug block behind an admin flag: new minimal app_settings KV table (none existed;
ai_settings is per-workspace, white_labels is branding) + lib/app-settings.js (cached,
refresh-on-write so status polls read a cached boolean, not a DB row).
routes/status.js includes `debug` ONLY when status_debug_enabled is on (persisted value
overrides the STATUS_DEBUG_ENABLED env default); when off the key is omitted entirely.
3. Admin toggle: GET/PUT /api/admin/status-debug (requirePlatformAdmin, mirrors the
branding endpoints) + a checkbox in the Admin tab "Status endpoint" section
(mirrors the branding checkbox). Takes effect on the next poll, no restart.
Tests: devices_connected always present+numeric and rises with a live socket (booted +
socket.io-client); debug present by default, admin flips OFF -> key omitted (loop_lag +
devices_connected remain) -> ON again, no restart; non-admin 403, anon 401; unit coverage
for getConnectedCount + app-settings default/override. Suite 289/289.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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>
Expose the new internal states so we can SEE the limiters biting during the alpha soak
instead of grepping logs. /api/status now carries debug: {
flap: {buckets, quarantined},
ota_download: {inFlight, servedThisWindow, shedThisWindow, windowCount},
maintenance: {deleted, ms, at, running}, // last status-log prune
log_coalescer_buffer,
}. Aggregate counts only (no device ids/secrets), cheap in-memory reads. stats()
added to flap-limiter + ota-download-guard (singleton prod state), getMaintenanceStats
from database. Asserted in the booted /api/status test.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Don't let telemetry/logging cook the loop under a storm.
- lib/log-coalescer.js: dedup+count high-frequency lines, flush ONE summarized line per
key per window ("[loop-lag] band=critical (x47 in 30s)"). Bounded buffer (auto-flush
at MAX_KEYS). Applied to the loop-lag "still loaded" line (band CHANGES stay immediate),
the per-request OTA check line, and "Device reconnected".
- loop-lag: event_loop_lag rows are BUFFERED and batch-inserted on a flush interval
(was a synchronous INSERT per sample); the buffer is bounded (drop-oldest). Its
retention prune now rides the Item-A chunkedDelete so this table can never repeat the
status_log bloat-then-freeze. /api/status still reads in-memory current (real-time
band unaffected).
- Bounded the previously un-evicted per-device Maps: content-ack limiter gets an idle
sweep (started in server.js); status-log-writer.lastWritten is capped (drop-oldest;
it only suppresses a redundant consecutive row, so eviction is safe).
Tests: N identical lines -> one counted line; single line verbatim; coalescer buffer
bounded under a distinct-key flood; content-ack Map swept of idle buckets.
loop-lag-integration updated for the batched-insert cadence. Suite 266/266.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Gates genuine reconnects PER DEVICE before the heavy register work (DB writes +
playlist build) runs, so a single flapping device can no longer saturate the
event loop and take down the server.
- Actuator is per-device, keyed on device_id (modeled on lastPlayLogAt). A device
is flagged only when it exceeds reconnectBaseMax genuine reconnects per window.
Same-socket playlist refreshes (isPlaylistRefresh) are exempt.
- Load-awareness is BANDED (normal/elevated/critical from the step-2 lag signal),
not a continuous controller. The band only MULTIPLIES an already-flagged
device's backoff; global lag never gates a healthy device.
- Hysteresis: escalate immediately while storming (tighten fast); decay one level
per reconnectReleaseMs of calm (release slow).
- HARD CEILING per device, independent of band and warm-up — a slow-ramp attacker
can't train through it.
- COLD START: for reconnectWarmupMs after boot, force the normal band and apply
only the hard ceiling, so a full-fleet reconnect after a deploy doesn't throttle
healthy screens. State is in-memory, resets on restart.
- Observability: every throttle engagement logs device, band, observed vs allowed
rate, and backoff. Throttled device gets device:throttled + a deferred disconnect.
Tests (api.test.js style):
- unit: healthy-never-throttled, storm-throttled-with-growing-backoff, band
multiplies backoff, hard-ceiling-even-in-warmup, warm-up leniency, neighbor
isolation, slow release.
- integration GATE (the required one): full-fleet reconnect right after restart
throttles NO healthy device; a single device storming IS throttled; a neighbor
stays unaffected while another storms.
- also fixes pre-existing test PORT collisions (my new integration files clashed
with totp.test.js:3979 and totp-keyrotation.test.js:3980 -> moved to 3982/3983);
full suite now green serially AND in parallel.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Continuously samples event-loop delay via perf_hooks.monitorEventLoopDelay()
(C++-backed histogram; cheap). Each window persists mean/p50/p99/max to a new
event_loop_lag table and recomputes a coarse load band (normal/elevated/critical)
from the window p99. Standalone value: current lag is exposed on /api/status and
band changes are logged, so site lag is diagnosable independent of throttling.
The band feeds the #142 reconnect throttle (next commit) but ships first as its
own subsystem.
- event_loop_lag is bounded from day one: indexed on sampled_at + scheduled prune
(LAG_TELEMETRY_RETENTION_DAYS, small default) modeled on the play_logs prune.
Deliberately NOT another unbounded-growth table.
- Band transitions are asymmetric: jump up immediately (tighten fast), release one
level at a time after N calm samples below a deadband (release slow, no flap).
Pure nextBand() function, unit-tested deterministically.
- config: LAG_SAMPLE_INTERVAL_MS, LAG_RESOLUTION_MS, LAG_TELEMETRY_RETENTION_DAYS,
LAG_PRUNE_INTERVAL_MS, LAG_ELEVATED_MS, LAG_CRITICAL_MS, LAG_RELEASE_SAMPLES.
- tests: band-transition unit tests; integration proves sampling persists, stays
bounded under the prune, and surfaces on /api/status.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
