Update app to use InfluxDB 3 Core

[jstirnaman]

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 feat: migrate to InfluxDB 3 Core with influxdb3-javascript client #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

• GET /api/devices - List all devices (SQL query)
• GET /api/devices/:deviceId - Get single device (SQL query with parameter)
• POST /api/devices/create - Create device with application token
• GET /api/measurements - Query telemetry data (SQL query)

---

Phase 2: Core Enhancements

Last Value Cache (LVC)

Sub-10ms query performance for latest device readings.

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.

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

# 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/)
• [InfluxDB 3 JavaScript Client](https://github.com/InfluxCommunity/influxdb3-js)
• [Query data with SQL](https://docs.influxdata.com/influxdb3/core/query-data/sql/)
• [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/)

---

Related

• PR feat: migrate to InfluxDB 3 Core with influxdb3-javascript client #18: Initial migration implementation
• Branch: claude/influxdb3-migration-v3-pMqwy