Connect to Cassandra Data in the Denodo Platform

Denodo Platform is a data virtualization product providing a single point of contact for enterprise database data. When paired with the CData JDBC Driver for Apache Cassandra, Denodo users can work with live Cassandra data alongside other enterprise data sources. This article walks through creating a virtual data source for Cassandra in the Denodo Virtual DataPort Administrator.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live Cassandra data. When you issue complex SQL queries to Cassandra, the driver pushes supported SQL operations, like filters and aggregations, directly to Cassandra and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze Cassandra data using native data types.

Create the Cassandra Virtual Port

To connect to live Cassandra data from Denodo, you need to copy the JDBC Driver JAR file to the external library directory for Denodo and create a new JDBC Data Source from the Virtual DataPort Administrator tool.

1. Download the CData JDBC Driver for Apache Cassandra installer, unzip the package, and run the JAR file to install the driver.
2. Copy the JAR File (and license file if it exists) from the installation location (typically C:\Program Files\CData\CData JDBC Driver for Apache Cassandra\lib\) to the Denodo external library directory (C:\Denodo\Denodo Platform\lib-external\jdbc-drivers\cdata-cassandra-19).
3. Open the Denodo Virtual DataPort Administrator tool and navigate to the Server Explorer tab.
4. Right-click "admin" and select New -> Data source -> JDBC.
5. Configure the JDBC Connection:
   • Name: your choice, e.g.: cassandra
   • Database adapter: Generic
   • Driver class path: C:\Denodo\Denodo Platform\lib-external\jdbc-drivers\cdata-cassandra-19
   • Driver class: cdata.jdbc.cassandra.CassandraDriver

   • Database URI: Set this to a JDBC URL using the necessary connection properties. For example,

     jdbc:cassandra:Database=MyCassandraDB;Port=7000;Server=127.0.0.1;

     Information on creating the Database URI follows:

     Built-In Connection String Designer

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

     java -jar cdata.jdbc.cassandra.jar

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

     Set the Server, Port, and Database connection properties to connect to Cassandra. Additionally, to use internal authentication set the User and Password connection properties.

6. Click the "Test connection" button to confirm the configuration and click Save.

View Cassandra Data in the VirtualPort Administrator Tool

After creating the data source, you can create a base view of Cassandra data for use in the Denodo Platform.

1. Click the "Create base view" button in the newly created VirtualPort (admin.Cassandra).
2. Expand the object tree and select the objects (tables) you wish to import.
3. Click the "Create selected" button to create views of the Cassandra data.
   Optional: Click "Create associations from foreign keys" to define relationships between the objects.
4. With the view(s) created, navigate to a table (cdata_cassandra_customer) in the Server Explorer and double-click the selected table.
5. In the new tab, click "Execution panel" to open a query panel.
6. Customize the query in the "Execute" tab or use the default:

   SELECT * FROM cdata_cassandra_customer CONTEXT ('i18n'='us_est', 'cache_wait_for_load'='true')
   

7. Click Execute to view the data.

With the base view created, you can now work with live Cassandra data like you would any other data source in Denodo Platform, for example, querying Cassandra in the Denodo Data Catalog.

Download a free, 30-day trial of the CData JDBC Driver for Apache Cassandra and start working with your live Cassandra data in Denodo Platform. Reach out to our Support Team if you have any questions.