adam
0f829e0380
Rearchitect so a single poller process is the sole owner of all SAS/SMART/ SES hardware I/O, serialized behind one gate and paced, writing results to Redis. The API/web and MQTT publisher become pure Redis readers — they no longer issue any subprocess and can restart freely without touching the bus. This addresses backplane/expander stress from concurrent + restart-triggered SMART/SES storms (the prior model re-ran a hardware sweep on every container start, and polled sg_ses 0x02+0x07 every 60s; 0x07 errored on the IOM6/ Xyratex expanders). - poller.py: paced sweep (inventory, SMART per-drive w/ gap, SES 0x02, ZFS, host/MegaRAID), startup jitter, single-instance Redis lock, LED-queue worker - services/hwgate.py: global serialization semaphore (POLL_CONCURRENCY=1) - services/store.py: Redis as the only producer<->consumer interface + LED queue - services/health.py: shared drive-health classifier (fixes overview double-count) - gate smartctl/sg_ses/zpool/ledctl; drop sg_ses 0x07 from the hot path - routers + temps read-only from the store; main.py drops the in-process poller - compose: 3 services (privileged poller + unprivileged app + redis) w/ pacing knobs
28 lines
1011 B
Python
28 lines
1011 B
Python
"""Global hardware-access gate.
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Every command that touches the SAS bus — smartctl, sg_ses, zpool, ledctl —
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must run inside this gate. It serializes hardware I/O so the poller can
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never fire a thundering herd of subprocesses at fragile SAS expanders
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(which on some shelves drop out and suspend pools under concurrent load).
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Concurrency defaults to 1 (fully serialized). It can be raised via
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POLL_CONCURRENCY for healthier backplanes, but 1 is the safe default.
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The gate is a per-process asyncio.Semaphore — only the poller process
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calls hardware, so a per-process gate is sufficient. The semaphore is
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created lazily on first use so it binds to the running event loop.
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"""
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import asyncio
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import os
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_sem: asyncio.Semaphore | None = None
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def gate() -> asyncio.Semaphore:
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"""Return the shared hardware semaphore (use as `async with gate():`)."""
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global _sem
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if _sem is None:
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n = max(1, int(os.environ.get("POLL_CONCURRENCY", "1")))
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_sem = asyncio.Semaphore(n)
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return _sem
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