KNX and Apache Druid Integration

Input and output integration overview

The KNX plugin listens for messages from the KNX home-automation bus via a KNX-IP interface, allowing for real-time data integration from KNX-enabled devices.

This plugin allows Telegraf to send JSON-formatted metrics to Apache Druid over HTTP, enabling real-time ingestion for analytical queries on high-volume time-series data.

Integration details

KNX

The KNX plugin allows for the listening to messages transmitted over the KNX home-automation bus. It establishes a connection with the KNX bus through a KNX-IP interface, making it compatible with various message datapoint types that KNX employs. The plugin supports service input configuration, wherein it remains active to listen for relevant metrics or events rather than relying solely on scheduled intervals. This inherent characteristic enables real-time data capture from the KNX systems, enhancing automation and integration possibilities for building management and smart home applications. Additionally, this plugin is designed to handle multiple measurements from the KNX data, allowing for a flexible categorization of metrics based on the derived datapoint types, thus broadening the scope of data integration in smart environments.

Apache Druid

This configuration uses Telegraf’s HTTP output plugin with json data format to send metrics directly to Apache Druid, a real-time analytics database designed for fast, ad hoc queries on high-ingest time-series data. Druid supports ingestion via HTTP POST to various components like the Tranquility service or native ingestion endpoints. The JSON format is ideal for structuring Telegraf metrics into event-style records for Druid’s columnar and time-partitioned storage engine. Druid excels at powering interactive dashboards and exploratory queries across massive datasets, making it an excellent choice for real-time observability and monitoring analytics when integrated with Telegraf.

Configuration

KNX

[[inputs.knx_listener]]
  ## Type of KNX-IP interface.
  ## Can be either "tunnel_udp", "tunnel_tcp", "tunnel" (alias for tunnel_udp) or "router".
  # service_type = "tunnel"

  ## Address of the KNX-IP interface.
  service_address = "localhost:3671"

  ## Measurement definition(s)
  # [[inputs.knx_listener.measurement]]
  #   ## Name of the measurement
  #   name = "temperature"
  #   ## Datapoint-Type (DPT) of the KNX messages
  #   dpt = "9.001"
  #   ## Use the string representation instead of the numerical value for the
  #   ## datapoint-type and the addresses below
  #   # as_string = false
  #   ## List of Group-Addresses (GAs) assigned to the measurement
  #   addresses = ["5/5/1"]

  # [[inputs.knx_listener.measurement]]
  #   name = "illumination"
  #   dpt = "9.004"
  #   addresses = ["5/5/3"]

Apache Druid

[[outputs.http]]
  ## Druid ingestion endpoint (e.g., Tranquility, HTTP Ingest, or Kafka REST Proxy)
  url = "http://druid-ingest.example.com/v1/post"

  ## Use POST method to send events
  method = "POST"

  ## Data format for Druid ingestion (expects JSON format)
  data_format = "json"

  ## Optional headers (may vary depending on Druid setup)
  # [outputs.http.headers]
  #   Content-Type = "application/json"
  #   Authorization = "Bearer YOUR_API_TOKEN"

  ## Optional timeout and TLS settings
  timeout = "10s"
  # tls_ca = "/path/to/ca.pem"
  # tls_cert = "/path/to/cert.pem"
  # tls_key = "/path/to/key.pem"
  # insecure_skip_verify = false

Input and output integration examples

KNX

1. Smart Home Energy Monitoring: Utilize the KNX plugin to monitor energy consumption across various devices in a smart home setup. By configuring measurements for different appliances, users can gather real-time data on power usage, enabling them to optimize energy consumption and reduce costs. This setup can also integrate with visualization tools to provide insights into energy trends and usage patterns.

2. Automated Lighting Control System: Leverage this plugin to listen for lighting status updates from KNX sensors in a building. By capturing measurements related to illumination, users can develop an automated lighting control system that adjusts the brightness based on the time of day or occupancy, enhancing comfort and energy efficiency.

3. HVAC Performance Tracking: Implement the KNX plugin to track temperature and ventilation data across different zones in a building. By monitoring these metrics, facilities managers can identify trends in HVAC performance, optimize climate control strategies, and proactively address maintenance needs to ensure consistent environmental quality.

4. Integrated Security Solutions: Use the plugin to capture data from KNX security sensors, such as door/window open/close statuses. This information can be routed into a central monitoring system, providing real-time alerts and enabling automated responses, such as locking doors or activating alarms, thus enhancing the building’s security posture.

Apache Druid

1. Real-Time Application Monitoring Dashboard: Use Telegraf to collect metrics from application servers and send them to Druid for immediate analysis and visualization in dashboards. Druid’s low-latency querying allows users to interactively explore system behavior in near real-time.

2. Security Event Aggregation: Aggregate and forward security-related metrics such as failed logins, port scans, or process anomalies to Druid. Analysts can build dashboards to monitor threat patterns and investigate incidents with millisecond-level granularity.

3. IoT Device Analytics: Collect telemetry from edge devices via Telegraf and send it to Druid for fast, scalable processing. Druid’s time-partitioned storage and roll-up capabilities are ideal for handling billions of small JSON events from sensors or gateways.

4. Web Traffic Behavior Exploration: Use Telegraf to capture web server metrics (e.g., requests per second, latency, error rates) and forward them to Druid. This enables teams to drill down into user behavior by region, device, or request type with subsecond query performance.

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