How to work with Couchbase 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 Couchbase, Spark can work with live Couchbase data. This article describes how to connect to and query Couchbase data from a Spark shell.

The CData JDBC Driver offers unmatched performance for interacting with live Couchbase data due to optimized data processing built into the driver. When you issue complex SQL queries to Couchbase, the driver pushes supported SQL operations, like filters and aggregations, directly to Couchbase 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 Couchbase data using native data types.

Install the CData JDBC Driver for Couchbase

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

Start a Spark Shell and Connect to Couchbase Data

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

   To connect using the Login method, set User, Password, and Server to the credentials for the account and the address of the server you want to connect to.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.couchbase.jar

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

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

   scala> val couchbase_df = spark.sqlContext.read.format("jdbc").option("url", "jdbc:couchbase:User=myuseraccount;Password=mypassword;Server=http://mycouchbaseserver;").option("dbtable","Customer").option("driver","cdata.jdbc.couchbase.CouchbaseDriver").load()
3. Once you connect and the data is loaded you will see the table schema displayed.

4. Register the Couchbase data as a temporary table:

   scala> couchbase_df.registerTable("customer")

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

   scala> couchbase_df.sqlContext.sql("SELECT FirstName, TotalDue FROM Customer WHERE FirstName = Bob").collect.foreach(println)

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

Using the CData JDBC Driver for Couchbase in Apache Spark, you are able to perform fast and complex analytics on Couchbase 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.