Connect to HDFS Data in RapidMiner

This article shows how you can easily integrate the CData JDBC driver for HDFS into your processes in RapidMiner. This article uses the CData JDBC Driver for HDFS to transfer HDFS data to a process in RapidMiner.

Connect to HDFS in RapidMiner as a JDBC Data Source

You can follow the procedure below to establish a JDBC connection to HDFS:

1. Add a new database driver for HDFS: Click Connections -> Manage Database Drivers.
2. In the resulting wizard, click the Add button and enter a name for the connection.
3. Enter the prefix for the JDBC URL:

   jdbc:hdfs:
   

4. Enter the path to the cdata.jdbc.hdfs.jar file, located in the lib subfolder of the installation directory.
5. Enter the driver class:

   cdata.jdbc.hdfs.HDFSDriver
   

   👁 The JDBC driver configuration. (Salesforce is shown.)
   
6. Create a new HDFS connection: Click Connections -> Manage Database Connections.
7. Enter a name for your connection.
8. For Database System, select the HDFS driver you configured previously.
9. Enter your connection string in the Host box.

   In order to authenticate, set the following connection properties:

   • Host: Set this value to the host of your HDFS installation.
   • Port: Set this value to the port of your HDFS installation. Default port: 50070

   Built-in Connection String Designer

   For assistance in constructing the JDBC URL, use the connection string designer built into the HDFS JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

   java -jar cdata.jdbc.hdfs.jar
   

   Fill in the connection properties and copy the connection string to the clipboard.

   👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)
   

   A typical connection string is below:

   Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;User=root;
   

10. Enter your username and password if necessary. 👁 The connection to the JDBC data source. (Salesforce is shown.)
    

You can now use your HDFS connection with the various RapidMiner operators in your process. To retrieve HDFS data, drag the Retrieve operator from the Operators view. 👁 A Retrieve operation to select data. (Salesforce is shown.)
With the Retrieve operator selected, you can then define which table to retrieve in the Parameters view by clicking the folder icon next to the "repository entry." In the resulting Repository Browser, you can expand your connection node to select the desired example set.

Finally, wire the output to the Retrieve process to a result, and run the process to see the HDFS data.