How to work with CockroachDB Data in Apache Spark using SQL

Apache Spark is a fast and general engine for large-scale data processing. When paired with the CData JDBC Driver for CockroachDB, Spark can work with live CockroachDB data. This article describes how to connect to and query CockroachDB data from a Spark shell.

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

Install the CData JDBC Driver for CockroachDB

Download the CData JDBC Driver for CockroachDB installer, unzip the package, and run the JAR file to install the driver.

Start a Spark Shell and Connect to CockroachDB Data

1. Open a terminal and start the Spark shell with the CData JDBC Driver for CockroachDB JAR file as the jars parameter: $ spark-shell --jars /CData/CData JDBC Driver for CockroachDB/lib/cdata.jdbc.cockroachdb.jar
2. With the shell running, you can connect to CockroachDB with a JDBC URL and use the SQL Context load() function to read a table.

   Set the following to connect to CockroachDB.

   • Server: The host name or IP address of the server.
   • Port: The port number of the CockroachDB server. If not specified, the default port is 26257.
   • Database: The name of the Cockroach database. If not specified, you connect to the user's default database.
   • User: The Cockroach DB user account used to authenticate.
   • Password: The password used to authenticate the user.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.cockroachdb.jar

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

   Configure the connection to CockroachDB, using the connection string generated above.

   scala> val cockroachdb_df = spark.sqlContext.read.format("jdbc").option("url", "jdbc:cockroachdb:User=root;Password=root;Database=system;Server=localhost;Port=26257").option("dbtable","Orders").option("driver","cdata.jdbc.cockroachdb.CockroachDBDriver").load()
3. Once you connect and the data is loaded you will see the table schema displayed.

4. Register the CockroachDB data as a temporary table:

   scala> cockroachdb_df.registerTable("orders")

5. Perform custom SQL queries against the Data using commands like the one below:

   scala> cockroachdb_df.sqlContext.sql("SELECT ShipName, ShipCity FROM Orders WHERE ShipCountry = USA").collect.foreach(println)

   You will see the results displayed in the console, similar to the following:

Using the CData JDBC Driver for CockroachDB in Apache Spark, you are able to perform fast and complex analytics on CockroachDB data, combining the power and utility of Spark with your data. Download a free, 30 day trial of any of the 200+ CData JDBC Drivers and get started today.