- poller.py: start lock_refresher() IMMEDIATELY after acquiring the lock,
before the startup jitter and restart-storm deferral. Those sleeps can
together exceed LOCK_TTL (restart defer is up to POLL_SWEEP_INTERVAL), so
with the refresher started afterward the lock could expire mid-deferral and
a second poller could begin sweeping concurrently — the exact hardware-storm
risk this design prevents.
- hwgate.py: clamp POLL_CONCURRENCY to 1 unless POLL_ALLOW_UNSAFE_CONCURRENCY
is set (fragile SAS hardware; >1 can drop expanders). Warn either way.
- build.sh: keep backward-compatible — a non-target first arg is treated as
the commit message (./build.sh "msg" still works), known targets select
web|poller|all.
Adversarial review (gpt-5.5) of the new architecture surfaced real gaps:
Hardware-safety / storm prevention:
- Restart-storm guard: on startup, defer the first sweep if a sweep ran
< POLL_SWEEP_INTERVAL ago (persisted in Redis), so deploy-cycling can no
longer trigger back-to-back full hardware sweeps (poller.py).
- Centralize pacing in the hardware gate: POLL_DRIVE_GAP is now held after
EVERY hardware op (SMART, SES, host, MegaRAID, ledctl), not just the
enclosure-drive loop (hwgate.py); removed the now-redundant per-loop sleeps.
- Single-instance lock made atomic (Lua compare-and-set / compare-and-expire)
and the refresher is now fatal on any error + has a done-callback, so a
dropped lock can never leave two pollers sweeping concurrently (store.py,
poller.py).
- Warn loudly when POLL_CONCURRENCY > 1.
Correctness:
- Heartbeat now actually writes: cache_set omits EX when ttl<=0 (Redis
rejects EX 0), so poller meta/last_sweep_ts persists — this also enables
the restart-storm guard and the poller_fresh health flag (cache.py).
- Web image runs a single uvicorn worker so the MQTT publisher is a true
singleton (two workers shared a client_id and flapped the broker) (Dockerfile).
- LED enqueue catches Redis errors -> API returns 503, not 500 (store.py).
Deploy independence:
- build.sh takes a target (web|poller|all) so web iterations never rebuild
or repush the poller image.
Nits: drop dead SMART_CACHE_TTL constant.
Decouple the privileged hardware poller from web iterations so a web
redeploy can never recreate/restart the poller (the backplane-touching
container). Two images from one Dockerfile via build targets:
- jbod-poller: privileged producer, ships smartmontools/sg3-utils/ledmon,
Redis-only deps (~197MB)
- jbod-web: unprivileged read-only consumer (REST/UI/MQTT), no hardware
tools, no /dev (~147MB)
Two compose projects sharing Redis over host networking:
- compose.infra.yml (jbod-infra): poller + redis — stable substrate
- compose.web.yml (jbod-web): app — 'up -d --build' touches only app
build.sh builds/pushes both images; split requirements-{poller,web}.txt;
dropped the combined docker-compose.yml; .dockerignore excludes tmp/ (keeps
the venv and the mqtt.env creds out of the build context).
