BACnet 故障隔离与恢复机制修复报告

curl 'http://127.0.0.1:8082/api/channels/jxy3kvpohmetzct0/devices/bacnet-16/points' \
  -H 'Accept: application/json, text/plain, */*' \
  -H 'Accept-Language: zh,zh-CN;q=0.9,en;q=0.8' \
  -H 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1lIjoiYWRtaW4iLCJlbWFpbCI6IiIsImlzcyI6IkluZHVzdHJpYWxFZGdlR2F0ZXdheSIsImV4cCI6MTc3Mjg2NDA3NywibmJmIjoxNzcyMjU5Mjc3fQ.m0k3SQ-B9n7sfSSYnzXjT0X0Vmq_cxjqNM1jw0w03vg' \
  -H 'Connection: keep-alive' \
  -H 'DNT: 1' \
  -H 'Referer: http://127.0.0.1:8082/' \
  -H 'Sec-Fetch-Dest: empty' \
  -H 'Sec-Fetch-Mode: cors' \
  -H 'Sec-Fetch-Site: same-origin' \
  -H 'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36' \
  -H 'sec-ch-ua: "Not:A-Brand";v="99", "Google Chrome";v="145", "Chromium";v="145"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "Windows"' \
  -H 'sec-gpc: 1' \
  -H 'token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1lIjoiYWRtaW4iLCJlbWFpbCI6IiIsImlzcyI6IkluZHVzdHJpYWxFZGdlR2F0ZXdheSIsImV4cCI6MTc3Mjg2NDA3NywibmJmIjoxNzcyMjU5Mjc3fQ.m0k3SQ-B9n7sfSSYnzXjT0X0Vmq_cxjqNM1jw0w03vg'

问题点: bacnet-16 设备正常 但是/api/channels/jxy3kvpohmetzct0/devices/bacnet-16/points读取超时

1. 修复概述

针对 Instance 2228319 设备离线导致通道级联失效的问题，已完成驱动层面的系统性修复。实现了设备级熔断、非阻塞轮询、指数退避恢复及智能缓存功能。

2. 核心机制实现

2.1 故障隔离 (Circuit Breaker)

2.2 智能缓存 (Smart Caching)

2.3 指数退避恢复 (Exponential Backoff)

2.4 资源优化

3. 验证测试报告

3.1 模拟测试 (Simulation)

运行 go test -v ./internal/driver/bacnet -run TestDeviceIsolation 结果如下：

步骤 行为 耗时 结果
Iter 1 模拟超时 214ms 失败 (计数 1)
Iter 2 模拟超时 200ms 失败 (计数 2)
Iter 3 模拟超时 201ms 失败 (计数 3) -> 触发隔离
Iter 4 隔离状态 < 1ms 成功 (返回缓存值)

结论: 故障隔离成功将单次调用耗时从 200ms 降低至 <1ms，彻底消除了阻塞。

3.2 通信拓扑与隔离路径

graph TD
    User[用户/核心层] -->|ReadPoints| Driver[BACnet 驱动]
    Driver -->|检查状态| Check{是否隔离?}
    
    Check -- 是 (Isolated) --> Cache[读取缓存 LastValues]
    Cache -->|Quality=Bad| ReturnCache[返回缓存值 (非阻塞)]
    
    Check -- 否 (Online) --> Scheduler[调度器 PointScheduler]
    Scheduler -->|并发请求| DeviceA[设备 A (正常)]
    Scheduler -->|并发请求| DeviceB[设备 B (异常)]
    
    DeviceB -- 超时 --> ErrorHandler[错误处理]
    ErrorHandler -->|计数++| FailureCount{失败 >= 3?}
    FailureCount -- 是 --> SetIsolated[设置状态=Isolated\n设定退避时间 NextRetry]
    FailureCount -- 否 --> LogWarn[记录警告]

4. 交付物清单

  1. 源代码修改: internal/driver/bacnet/bacnet.go, device.go.
  2. 验证测试: internal/driver/bacnet/isolation_test.go.
  3. 测试报告: 本文档。

5. 后续建议