Update app to use InfluxDB 3 Core

@jstirnaman is already working on this.

Since Feb 10, 2026.

Use InfluxDB 3 Core

Overview

Migrate the IoT API sample application from InfluxDB 2.x to InfluxDB 3 Core using the @influxdata/influxdb3-client JavaScript client library.

---

Phase 1: Core Migration ✅

Environment Changes

Variable | New Value | Replaces
-- | -- | --
INFLUX_HOST | http://localhost:8181 | INFLUX_URL
INFLUX_DATABASE | iot_center | INFLUX_BUCKET
INFLUX_DATABASE_AUTH | iot_center_devices | INFLUX_BUCKET_AUTH
INFLUX_TOKEN | Admin token | Same
~~INFLUX_ORG~~ | Removed | Not used in InfluxDB 3

---

References

• InfluxDB 3 Core Documentation


• InfluxDB 3 JavaScript Client


• Query data with SQL


• Last Value Cache


• Processing Engine

---

Related

• PR #18: Initial migration implementation


• Branch: claude/influxdb3-migration-v3-pMqwy

## Use InfluxDB 3 Core

### Overview

Migrate the IoT API sample application from InfluxDB 2.x to InfluxDB 3 Core using the `@influxdata/influxdb3-client` JavaScript client library.

---

## Phase 1: Core Migration ✅

### Environment Changes
| Variable | New Value | Replaces |
|----------|-----------|----------|
| `INFLUX_HOST` | `http://localhost:8181` | `INFLUX_URL` |
| `INFLUX_DATABASE` | `iot_center` | `INFLUX_BUCKET` |
| `INFLUX_DATABASE_AUTH` | `iot_center_devices` | `INFLUX_BUCKET_AUTH` |
| `INFLUX_TOKEN` | Admin token | Same |
| ~~`INFLUX_ORG`~~ | Removed | Not used in InfluxDB 3 |

### Client Library Migration
- Replace `@influxdata/influxdb-client` with `@influxdata/influxdb3-client` v2.0.0
- Use `InfluxDBClient` class with `{ host, token }` configuration
- Use `Point` class for line protocol construction
- Use `client.query(sql, database)` for SQL queries
- Use `client.write(data, database)` for writes

### Query Language Migration
- Convert all Flux queries to SQL
- InfluxDB 3 Core supports SQL queries only (no Flux)
- Query limit: Last 72 hours of data (Core limitation)

### Authentication Changes
- InfluxDB 3 Core does not have the Authorizations API
- Implement application-level device tokens stored in `iot_center_devices` database
- Generate tokens using `crypto.randomBytes(32).toString('hex')`
- Store device credentials as line protocol with `deviceauth` measurement

### API Endpoints Migrated
- [x] `GET /api/devices` - List all devices (SQL query)
- [x] `GET /api/devices/:deviceId` - Get single device (SQL query with parameter)
- [x] `POST /api/devices/create` - Create device with application token
- [x] `GET /api/measurements` - Query telemetry data (SQL query)

---

## Phase 2: Core Enhancements

### Last Value Cache (LVC)
Sub-10ms query performance for latest device readings.

```bash
influxdb3 create last_cache \
--database iot_center \
--table environment \
--key-columns deviceId \
--value-columns Temperature,Humidity,Pressure,CO2
```

**Use case**: Real-time dashboard showing current sensor values for all devices.

### Distinct Value Cache (DVC)
Fast metadata lookups without full table scans.

```bash
influxdb3 create distinct_cache \
--database iot_center \
--table environment \
--columns deviceId,deviceType,location
```

**Use case**: Populate device filter dropdowns, list available locations.

### Processing Engine
Python plugins for data processing triggered by WAL writes, schedules, or HTTP requests.

**Example: Temperature Alert Plugin**
```python
# temperature_alert.py
def process_writes(influxdb3_local, table_batches, args):
for table_batch in table_batches:
if table_batch["table_name"] == "environment":
for row in table_batch["rows"]:
if row.get("Temperature", 0) > args.get("threshold", 30):
influxdb3_local.write(
f'alerts,deviceId={row["deviceId"]},type=temperature '
f'value={row["Temperature"]},message="High temperature"'
)
```

**Use cases**:
- Temperature threshold alerts (WAL trigger)
- Daily device health summary (scheduled)
- On-demand data aggregation (HTTP request)

---

## Technical Notes

### InfluxDB 3 Core Limitations
| Limitation | Description |
|------------|-------------|
| Query window | Last 72 hours only |
| Authentication | No resource tokens (use application-level auth) |
| Availability | Single node only |
| Processing Engine | Python plugins only |

### Data Model Changes
| InfluxDB 3 | InfluxDB 2.x |
|------------|--------------|
| Database | Bucket |
| Table | Measurement |
| Tags | Tags |
| Fields | Fields |

---

## References

- [[InfluxDB 3 Core Documentation](https://docs.influxdata.com/influxdb3/core/)](https://docs.influxdata.com/influxdb3/core/)
- [[InfluxDB 3 JavaScript Client](https://github.com/InfluxCommunity/influxdb3-js)](https://github.com/InfluxCommunity/influxdb3-js)
- [[Query data with SQL](https://docs.influxdata.com/influxdb3/core/query-data/sql/)](https://docs.influxdata.com/influxdb3/core/query-data/sql/)
- [[Last Value Cache](https://docs.influxdata.com/influxdb3/core/query-data/last-value-cache/)](https://docs.influxdata.com/influxdb3/core/query-data/last-value-cache/)
- [[Processing Engine](https://docs.influxdata.com/influxdb3/core/process-data/process-engine/)](https://docs.influxdata.com/influxdb3/core/process-data/process-engine/)

---

## Related

- PR #18: Initial migration implementation
- Branch: `claude/influxdb3-migration-v3-pMqwy`