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docs: align jt808 mileage storage

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lingniu
2026-07-01 04:00:57 +08:00
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commit e97116202b
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12
docs/operations/jt808-daily-mileage-runbook.md
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@@ -2,11 +2,11 @@
## Scope
The analytics app can calculate daily mileage from JT808 telemetry only. It consumes `vehicle.event.jt808.v1`, keeps the rolling per-vehicle daily state in Redis, and saves the current daily result into the common `vehicle-stat` metric repository.
The analytics app can calculate daily mileage from JT808 telemetry only. It consumes `vehicle.event.jt808.v1` and saves the current daily result into the common `vehicle-stat` metric repository.
## Storage
There is no separate JT808 daily-mileage table. Runtime state is stored under the configured JT808 state store so the stream can continue after restart. The derived metric is written through `VehicleStatRepository.saveDailyStat(...)` into the common JDBC/MySQL metric table `vehicle_stat_metric`.
There is no separate JT808 daily-mileage table and no Redis mileage state. The current day start total, latest total, and derived daily mileage are all stored in the common JDBC/MySQL metric table `vehicle_stat_metric`.
The JT808 daily-mileage value is calculated from the GPS total mileage reported in location additional information:
@@ -15,7 +15,7 @@ daily_mileage_km = last_total_mileage_km - first_total_mileage_km
calculation_method = JT808_TOTAL_MILEAGE_DIFF
```
The metric is saved only after at least two ordered JT808 location points with valid `total_mileage_km` have been received for the same vehicle and local day. If the difference is negative, no metric row is saved for that state update.
The first valid JT808 location point for a vehicle and local day stores the day start total and writes `daily_mileage_km=0.0`. Later ordered points update the latest total and the derived `daily_mileage_km`. If a later total mileage is lower than the stored start or latest total, the update is ignored and the previous metric remains.
## Runtime Settings
@@ -27,10 +27,6 @@ VEHICLE_STAT_JT808_MILEAGE_ENABLED=true
MYSQL_JDBC_URL=<jdbc-url>
MYSQL_USERNAME=<user>
MYSQL_PASSWORD=<password>
REDIS_HOST=<host>
REDIS_PORT=6379
REDIS_DATABASE=50
REDIS_PASSWORD=<password>
```
Algorithm defaults use the Asia/Shanghai daily boundary. The rolling state stores only the fields needed by the GPS total-mileage difference calculation.
Algorithm defaults use the Asia/Shanghai daily boundary. Restart recovery reads the same `vehicle_stat_metric` rows, so no separate mileage state store is required.