# JT808 Daily Mileage Streaming

## 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 or memory, and upserts the current daily result into MySQL.

## Required MySQL Table

```sql
create table if not exists vehicle_daily_mileage_jt808 (
  stat_date date not null,
  vehicle_key varchar(64) not null,
  vin varchar(32) null,
  phone varchar(32) null,
  first_event_time timestamp null,
  last_event_time timestamp null,
  gps_mileage_km decimal(12,3) not null,
  speed_integral_km decimal(12,3) not null,
  odometer_mileage_km decimal(12,3) null,
  accepted_points int not null,
  bad_jump_segments int not null,
  long_gap_segments int not null,
  out_of_order_points int not null,
  odometer_anomalies int not null,
  data_quality varchar(16) not null,
  updated_at timestamp not null default current_timestamp on update current_timestamp,
  primary key (stat_date, vehicle_key),
  key idx_vehicle_daily_mileage_jt808_vehicle_date (vehicle_key, stat_date)
);
```

## Runtime Settings

Set these in Portainer or Nacos, without committing secrets:

```text
KAFKA_TOPIC_JT808_EVENT=vehicle.event.jt808.v1
VEHICLE_STAT_JT808_MILEAGE_ENABLED=true
VEHICLE_STAT_JT808_STATE_STORE=redis
MYSQL_JDBC_URL=jdbc:mysql://<host>:3306/<database>?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai
MYSQL_USERNAME=<user>
MYSQL_PASSWORD=<password>
REDIS_HOST=<host>
REDIS_PORT=6379
REDIS_DATABASE=50
REDIS_PASSWORD=<password>
```

Algorithm defaults are Asia/Shanghai daily boundary, 5 minute max segment gap, 200 km/h max implied speed, and short-gap jump guard of 300 meters within 10 seconds.