node-red-contrib-questdb

Node-RED nodes for writing data to QuestDB time-series database using the Influx Line Protocol (ILP).

Features

• High-performance writes using QuestDB's native ILP protocol
• Connection pooling with automatic reconnection
• Multiple protocols: HTTP, HTTPS, TCP, TCPS
• Authentication: Basic auth and Bearer token support
• TLS/SSL: Full TLS support with certificate verification options
• Flexible data mapping: Map message fields to QuestDB columns
• Type support: Symbols, floats, integers, longs, booleans, strings, timestamps, arrays, and decimals
• Auto-flush: Configurable automatic flushing by row count or time interval
• Examples included: Ready-to-use flow examples

Installation

Via Node-RED Palette Manager

1. Open Node-RED
2. Go to Menu > Manage palette > Install
3. Search for node-red-contrib-questdb
4. Click Install

Via npm

cd ~/.node-red
npm install node-red-contrib-questdb

Then restart Node-RED.

Nodes

QuestDB Write

Writes data to QuestDB using the ILP protocol.

Configuration

Connection Settings:

• Protocol: HTTP (default), HTTPS, TCP, or TCPS
• Host: QuestDB server hostname or IP
• Port: 9000 (HTTP) or 9009 (TCP)

Security Settings:

• Enable Auth: Toggle authentication
• Auth Type: Username/Password or Bearer Token
• TLS Verify: Verify server certificate (for HTTPS/TCPS)

Advanced Settings:

• Auto Flush: Enable automatic flushing
• Flush Rows: Number of rows before auto-flush (default: 75000)
• Flush Interval: Time interval for auto-flush in ms (default: 1000)
• Request Timeout: HTTP request timeout in ms
• Buffer Size: Initial and maximum buffer sizes

Input Message Format

msg.topic = "table_name";
msg.payload = {
    symbols: {
        tag_name: "sensor1",      // Indexed string columns
        location: "warehouse"
    },
    columns: {
        temperature: 23.5,        // Auto-detected as float
        humidity: 65,             // Auto-detected as float
        status: "active",         // String column
        alert: true               // Boolean column
    },
    timestamp: Date.now()         // Optional: milliseconds or Date object
};

Explicit Type Specification

For precise control over column types:

msg.payload = {
    symbols: { device: "sensor1" },
    columns: {
        value: { value: 123456789, type: "long" },
        price: { value: "123.456789", type: "decimal" },
        readings: { value: [1.1, 2.2, 3.3], type: "array", elementType: "double" }
    },
    timestamp: Date.now()
};

Supported Types:

• int / integer - 32-bit signed integer
• long - 64-bit signed integer
• float - 32-bit floating point
• double - 64-bit floating point
• decimal - Arbitrary precision decimal
• string - Text value
• boolean - true/false
• timestamp - Date/time value
• array - Array with auto-detected element type
• array_double - Array of doubles
• array_long - Array of longs
• array_string - Array of strings

QuestDB Mapper

Maps incoming message fields to QuestDB ILP structure. Useful for transforming data from various sources.

Configuration

• Table Name: Target table (or use msg.topic)
• Timestamp Field: Path to timestamp field in message
• Symbol Mappings: Map source fields to QuestDB symbols
• Column Mappings: Map source fields to columns with type conversion

Example

Input message:

{
    topic: "sensors",
    payload: {
        device: "sensor1",
        temp: 23.5,
        readings: [1.1, 2.2, 3.3],
        ts: 1699999999000
    }
}

With mappings:

• Symbol: payload.device → device_id
• Column: payload.temp → temperature (double)
• Column: payload.readings → values (array_double)
• Timestamp: payload.ts

Output:

{
    topic: "sensors",
    payload: {
        symbols: { device_id: "sensor1" },
        columns: {
            temperature: { value: 23.5, type: "double" },
            values: { value: [1.1, 2.2, 3.3], type: "array", elementType: "double" }
        },
        timestamp: 1699999999000
    }
}

Examples

The package includes ready-to-use examples. After installation:

1. Open Node-RED
2. Go to Menu > Import
3. Select Examples > node-red-contrib-questdb

Available Examples

1. Basic Write - Simple sensor data write
2. Batch Write - Writing arrays of measurements
3. Using Mapper - Transform MQTT data for QuestDB
4. Direct Value Write - Simple numeric writes
5. Multiple Tables - Writing to different tables
6. With Timestamp - Custom timestamp handling
7. Continuous Data - Generating continuous metrics

QuestDB Setup

Using Docker

docker run -p 9000:9000 -p 9009:9009 questdb/questdb

Connection String Format

The node uses QuestDB's connection string format internally:

http::addr=localhost:9000;auto_flush_rows=75000;auto_flush_interval=1000;

Compatibility

• Node-RED: >= 2.0.0
• Node.js: >= 14.0.0
• QuestDB: >= 6.0 (recommended: latest)

Troubleshooting

Connection Issues

1. Verify QuestDB is running: curl http://localhost:9000
2. Check firewall settings for ports 9000/9009
3. For HTTPS/TCPS, ensure certificates are properly configured

Data Not Appearing

1. Check the node status indicator (green = connected)
2. Verify table creation in QuestDB console
3. Enable debug output to see write confirmations

Performance Tips

1. Use symbols for frequently queried columns (they're indexed)
2. Batch writes when possible using arrays
3. Adjust auto-flush settings based on your write patterns

License

MIT

Author

Holger Amort

Links

• QuestDB Documentation
• QuestDB Node.js Client
• GitHub Repository
• Report Issues