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ETL Data Into Stardog

This page discusses Stardog’s NiFi integration support to ETL data sources to Stardog.

Page Contents
  1. Overview
  2. Installation
  3. Running NiFi
    1. Example NiFi Workflow


Stardog supports integration with Apache Nifi, a scalable, robust ETL platform that can be used to load and transform data from Enterprise data sources to Stardog. Stardog includes three Processors for loading, querying and updating a Stardog database.


To install NiFi and the Stardog connector:

  1. Go to and download the latest binary release ( as of this writing)
  2. Decompress the zip file to a local folder
  3. Download the Stardog NiFi nar files from into the lib folder in the NiFi installation folder

Running NiFi

Start the NiFi server by running the command bin/ start in the NiFi installation folder. It takes up to a minute for the NiFi server to start. Once the server is running you can go to the URL http://localhost:8080/nifi in your browser, which will show the empty workflow. You can drag the processor icon from the top left to the empty canvas and add a Stardog processor:

Nifi Demo

Once the processor is added you can change the parameters to specify the Stardog server to connect to, credentials, etc. See the following example for more details:

Example NiFi Workflow

An example NiFi workflow is provided in the Stardog Examples GitHub repository. The workflow is for loading the Coivd19 dataset published by New York Times on GitHub into Stardog. It contains three processors:

  1. NiFi built-in processor to retrieve the CSV file from GitHub.
  2. StardogPut processor that ingests the CSV file into a staging graph in Stardog using the Stardog mappings available in the examples repository.
  3. StardogQuery processor that copies the staging graph to the default graph and updates the last modification time.

Follow these steps to upload this workflow to your NiFi instance (see the screencast below and refer to Apache NiFi user interface for terminology):

  1. From the Operate Palette, click the “Upload Template” button and select the covid19-stardog.xml file.
  2. Drag the “Template” icon from the Components Toolbar onto the canvas.
  3. Unselect the processors by clicking an empty spot on the canvas and then select the StardogPut processor to configure the connection details and point to the correct location for the mappings file nyt-covid.sms.
  4. Modify the connection details for the StardogQuery processor in a similar way.

Nifi Demo

The example is created to run every hour so if you have leave NiFi running the data will be fetched, transformed and uploaded into Stardog every hour.

As an alterative to supplying the Stardog url and credentials in every Stardog processor, you can configure the Stardog Connection Service just once and then reference that service in each Stardog processor.