Cloudera Impala JDBC Example

This example shows how to build and run a maven-based project that executes SQL queries on Cloudera Impala using JDBC. Cloudera Impala is a native Massive Parallel Processing (MPP) query engine which enables users to perform interactive analysis of data stored in HBase or HDFS.

Here are links to more information on Cloudera Impala:

• Cloudera Enterprise RTQ

• Cloudera Impala Documentation

• Cloudera Impala JDBC Documentation

• Impala-User Google Group

To use the Cloudera Impala JDBC driver in your own maven-based project you can copy the <dependency> and <repository> elements from this project's pom to your own instead of manually downloading the JDBC driver jars.

Dependencies

To build the project you must have Maven 2.x or higher installed. Maven info is here.

To run the project you must have access to a Hadoop cluster running Cloudera Impala with at least one populated table defined in the Hive Metastore.

Configure the example

To configure the example you must:

• Select or create the table(s) to query against.
• Set the query and impalad host in the example source file

These steps are described in more detail below.

#####Select or create the table(s) to run the example with For this example I will use one of the Hue Beeswax sample tables. I can see the tables using Hue as in the screenshot below:

Set the query and impalad host

Edit these two setting in the ClouderaImpalaJdbcExample source file:

• Set the SQL Statement

private static final String SQL_STATEMENT = "SELECT description FROM sample_07 limit 10";

• Set the host for the impalad you want to connect to:

private static final String IMPALAD_HOST = "MyImpaladHost";

B uilding the project

To build the project, run the command:

mvn clean compile

from the root of the project directory. There is a build.sh script for your convenience.

Running the example

To run the example, use the command:

mvn exec:java -Dexec.mainClass=com.cloudera.example.ClouderaImpalaJdbcExample

from the root of the project directory. There is a run.sh script for your convenience.

Sample output

Here is sample output from running the example:

$ ./run.sh
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building cloudera-impala-jdbc-example 1.0
[INFO] ------------------------------------------------------------------------ 
...
[INFO] --- exec-maven-plugin:1.2.1:java (default-cli) @ cloudera-impala-jdbc-example ---

Cloudera Impala JDBC Example
Using Connection URL: jdbc:hive2://192.168.171.100:21050/;auth=noSasl
Running Query: SELECT description FROM sample_07 limit 10

== Begin Query Results ======================
All Occupations
Management occupations
Chief executives
General and operations managers
Legislators
Advertising and promotions managers
Marketing managers
Sales managers
Public relations managers
Administrative services managers
== End Query Results =======================


[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.705s
[INFO] Finished at: Fri May 10 12:07:47 PDT 2013
[INFO] Final Memory: 7M/81M
[INFO] ------------------------------------------------------------------------