Installing the Java runtime on your Vertica cluster

The HCatalog Connector requires a 64-bit Java Virtual Machine (JVM). The JVM must support Java 6 or later, and must be the same version as the one installed on your Hadoop nodes.

Installing Java on your Vertica cluster is a two-step process:

1. Install a Java runtime on all of the hosts in your cluster.

2. Set the JavaBinaryForUDx configuration parameter to tell Vertica the location of the Java executable.

Installing a Java runtime

For Java-based features, Vertica requires a 64-bit Java 6 (Java version 1.6). Vertica supports runtimes from either Oracle or OpenJDK. You can choose to install either the Java Runtime Environment (JRE) or Java Development Kit (JDK), since the JDK also includes the JRE.

Many Linux distributions include a package for the OpenJDK runtime. See your Linux distribution's documentation for information about installing and configuring OpenJDK.

To install the Oracle Java runtime, see the Java Standard Edition (SE) Download Page. You usually run the installation package as root in order to install it. See the download page for instructions.

Once you have installed a JVM on each host, ensure that the java command is in the search path and calls the correct JVM by running the command:

$ java -version

This command should print something similar to:

java version "1.8.0_102"
Java(TM) SE Runtime Environment (build 1.8.0_102-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode)

Setting the JavaBinaryForUDx configuration parameter

The JavaBinaryForUDx configuration parameter tells Vertica where to look for the JRE to execute Java UDxs. After you have installed the JRE on all of the nodes in your cluster, set this parameter to the absolute path of the Java executable. You can use the symbolic link that some Java installers create (for example /usr/bin/java). If the Java executable is in your shell search path, you can get the path of the Java executable by running the following command from the Linux command line shell:

$ which java
/usr/bin/java

If the java command is not in the shell search path, use the path to the Java executable in the directory where you installed the JRE. Suppose you installed the JRE in /usr/java/default (which is where the installation package supplied by Oracle installs the Java 1.6 JRE). In this case the Java executable is /usr/java/default/bin/java.

You set the configuration parameter by executing the following statement as a database superuser:

=> ALTER DATABASE DEFAULT SET PARAMETER JavaBinaryForUDx = '/usr/bin/java';

See ALTER DATABASE for more information on setting configuration parameters.

To view the current setting of the configuration parameter, query the CONFIGURATION_PARAMETERS system table:

=> \x
Expanded display is on.
=> SELECT * FROM CONFIGURATION_PARAMETERS WHERE parameter_name = 'JavaBinaryForUDx';
-[ RECORD 1 ]-----------------+----------------------------------------------------------
node_name                     | ALL
parameter_name                | JavaBinaryForUDx
current_value                 | /usr/bin/java
default_value                 |
change_under_support_guidance | f
change_requires_restart       | f
description                   | Path to the java binary for executing UDx written in Java

Once you have set the configuration parameter, Vertica can find the Java executable on each node in your cluster.