Load Cassandra Data to a Database Using Embulk

Embulk is an open source bulk data loader. When paired with the CData JDBC Driver for Apache Cassandra, Embulk easily loads data from Cassandra to any supported destination. In this article, we explain how to use the CData JDBC Driver for Apache Cassandra in Embulk to load Cassandra data to a MySQL dtabase.

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).

Configure a JDBC Connection to Cassandra Data

Before creating a bulk load job in Embulk, note the installation location for the JAR file for the JDBC Driver (typically C:\Program Files\CData\CData JDBC Driver for Apache Cassandra\lib).

Embulk supports JDBC connectivity, so you can easily connect to Cassandra and execute SQL queries. Before creating a bulk load job, create a JDBC URL for authenticating with Cassandra.

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

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.

Below is a typical JDBC connection string for Cassandra:

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

Load Cassandra Data in Embulk

After installing the CData JDBC Driver and creating a JDBC connection string, install the required Embulk plugins.

Install Embulk Input & Output Plugins

1. Install the JDBC Input Plugin in Embulk.
   https://github.com/embulk/embulk-input-jdbc/tree/master/embulk-input-jdbc

embulk gem install embulk-input-jdbc

2. In this article, we use MySQL as the destination database. You can also choose SQL Server, PostgreSQL, or Google BigQuery as the destination using the output Plugins.
   https://github.com/embulk/embulk-output-jdbc/tree/master/embulk-output-mysql

   embulk gem install embulk-output-mysql
   

With the input and output plugins installed, we are ready to load Cassandra data into MySQL using Embulk.

Create a Job to Load Cassandra Data

Start by creating a config file in Embulk, using a name like cassandra-mysql.yml.

1. For the input plugin options, use the CData JDBC Driver for Apache Cassandra, including the path to the driver JAR file, the driver class (e.g. cdata.jdbc.cassandra.CassandraDriver), and the JDBC URL from above
2. For the output plugin options, use the values and credentials for the MySQL database

Sample Config File (cassandra-mysql.yml)

in:
	type: jdbc
	driver_path: C:\Program Files\CData[product_name] 20xx\lib\cdata.jdbc.cassandra.jar
	driver_class: cdata.jdbc.cassandra.CassandraDriver
	url: jdbc:cassandra:Database=MyCassandraDB;Port=7000;Server=127.0.0.1;
	table: "Customer"
out: 
	type: mysql
	host: localhost
	database: DatabaseName
	user: UserId
	password: UserPassword
	table: "Customer"
	mode: insert

After creating the file, run the Embulk job.

embulk run cassandra-mysql.yml

After running the the Embulk job, find the Salesforce data in the MySQL table.

Load Filtered Cassandra Data

In addition to loading data directly from a table, you can use a custom SQL query to have more granular control of the data loaded. You can also perform increment loads by setting a last updated column in a SQL WHERE clause in the query field.

in:
	type: jdbc
	driver_path: C:\Program Files\CData[product_name] 20xx\lib\cdata.jdbc.cassandra.jar
	driver_class: cdata.jdbc.cassandra.CassandraDriver
	url: jdbc:cassandra:Database=MyCassandraDB;Port=7000;Server=127.0.0.1;
	query: "SELECT City, TotalDue FROM Customer WHERE [RecordId] = 1"
out: 
	type: mysql
	host: localhost
	database: DatabaseName
	user: UserId
	password: UserPassword
	table: "Customer"
	mode: insert

More Information & Free Trial

By using CData JDBC Driver for Apache Cassandra as a connector, Embulk can integrate Cassandra data into your data load jobs. And with drivers for more than 200+ other enterprise sources, you can integrate any enterprise SaaS, big data, or NoSQL source as well. Download a 30-day free trial and get started today.