Monitoring 34 NTP Synchronized Clocks from a Cron Job

说明与用途

使用 Python cron 作业监控 34 台 NTP 同步 LED 时钟，轮询其 HTTP 状态，并在偏移量超过约 1 秒时发出警报。

问题

34 wall‑clock displays across three buildings were not being monitored for time accuracy, risking incorrect time display.

结果

All 34 displays are now monitored; alerts fire when a display’s offset exceeds ~1 s or when it becomes unreachable, preventing unnoticed drift.

工作流

• 1. Verify upstream NTP server sanity with ntplib.
• 2. Define human‑perceivable offset threshold (~1 s).
• 3. Load fleet list from JSON.
• 4. Concurrently poll each device’s /status endpoint.
• 5. Normalize JSON response to internal schema.
• 6. Evaluate offset, last_sync_age, and online status.
• 7. Trigger alerts if offset > threshold or device offline.
• 8. Schedule script via cron for regular monitoring.

证据

Each unit exposes an HTTP status endpoint.

来源

I initially monitored each display's offset from the NTP server and alerted at > 500 ms.

来源

The shape I normalize to internally looks like this: {"id":"BLD-A-F2-REG-01",...}

来源