Connect to Impala Data in CloverDX (formerly CloverETL)

The CData JDBC Driver for Impala enables you to use the data transformation components in CloverDX (formerly CloverETL) to work with Impala as sources and destinations. In this article, you will use the JDBC Driver for Impala to set up a simple transfer into a flat file. The CData JDBC Driver for Impala enables you to use the data transformation components in CloverDX (formerly CloverETL) to work with Impala as sources and destinations. In this article, you will use the JDBC Driver for Impala to set up a simple transfer into a flat file.

Connect to Impala as a JDBC Data Source

1. Create the connection to Impala data. In a new CloverDX graph, right-click the Connections node in the Outline pane and click Connections -> Create Connection. The Database Connection wizard is displayed.
2. Click the plus icon to load a driver from a JAR. Browse to the lib subfolder of the installation directory and select the cdata.jdbc.apacheimpala.jar file.
3. Enter the JDBC URL.

   In order to connect to Apache Impala, set the Server, Port, and ProtocolVersion. You may optionally specify a default Database. To connect using alternative methods, such as NOSASL, LDAP, or Kerberos, refer to the online Help documentation.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.apacheimpala.jar

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

   A typical JDBC URL is below:

   jdbc:apacheimpala:Server=127.0.0.1;Port=21050;

Query Impala Data with the DBInputTable Component

1. Drag a DBInputTable from the Readers selection of the Palette onto the job flow and double-click it to open the configuration editor.
2. In the DB connection property, select the Impala JDBC data source from the drop-down menu.
3. Enter the SQL query. For example: SELECT City, CompanyName FROM Customers WHERE Country = 'US'

Write the Output of the Query to a UniversalDataWriter

1. Drag a UniversalDataWriter from the Writers selection onto the jobflow.
2. Double-click the UniversalDataWriter to open the configuration editor and add a file URL.
3. Right-click the DBInputTable and then click Extract Metadata.
4. Connect the output port of the DBInputTable to the UniversalDataWriter.
5. In the resulting Select Metadata menu for the UniversalDataWriter, choose the Customers table. (You can also open this menu by right-clicking the input port for the UniversalDataWriter.)
6. Click Run to write to the file.