Configure the Java environment

Overview Copied

Java-based components require a Java virtual environment (JVM) to run. This includes the following components and plugins:

This topic walks you through the files and setup required before you start configuring Java-based components.

Required files Copied

Before you begin, check that you have the complete set of Netprobe files on the machine where you are running the Java-based plugin.

These files are bundled in the Netprobe binary package, which you can download from ITRS Downloads.

In addition, check that you have one of the supported Java Runtimes or Java Development Kits on the machine. These packages are available from their respective vendor sites.

Note

The supported Java version may be different, depending on the plugin you plan to run. For guidance on supported versions, see Application and plugin specific information in Geneos Compatibility Matrix.

For Windows platforms, the supported Java installation typically does not require the additional configuration steps outlined in this topic. Please proceed only when you encounter errors with your Java-based plugin.

Certain plugins require additional vendor-specific files to run. You must obtain these from a licensed distribution, as does not make these files available as part of the Netprobe for this reason. In these cases, refer to the plugin user guide for the required vendor-specific files.

Java virtual machine parameters Copied

The Netprobe launches the Java virtual machine (JVM) with the following parameters:

Parameter Description
java.class.path This parameter contains a list of third-party and user-defined classes that the JVM needs for running Java applications. The Netprobe uses all the JAR files found in the current directory, as well as the on the GENEOS_JARS environment variable.
java.library.path

This parameter provides the path to the native libraries that the JVM requires.

Typically, the java.library.path is set to the location of the launchpad library file, and the current working directory. When JAVA_HOME is defined and the Java library is found, their locations are also included in the java.library.path.

java.home This parameter sets the Java home of the embedded JVM.

Once the Netprobe starts, you can find and verify the values of the parameters in the Netprobe log.

Disabling TLS or ciphers Copied

To manually disable older TLS versions or other weak ciphers for Java applications, add the cipher you want to disable to the jdk.tls.disabledAlgorithms property of the java.security file. For example, adding TLSv1, TLSv1.1, and CBC to the list disables the TLSv1 and TLSv1.1 protocols, and the CBC ciphers.


 #Example:
  jdk.tls.disabledAlgorithms=TLSv1, TLSv1.1, CBC

The location of the java.security file is as follows:

For more information on TLS ciphers, see TLS ciphers in Secure Communications.

Configure the Java home Copied

Java home as used by the Netprobe is set following this configuration precedence:

  1. Commandline option — You are provided with a commandline option to specify the JRE to be used by the Netprobe. This will only be loaded when a Java plugin is configured. See Netprobe Command-line Options.

  2. JAVA_HOME environment variable — Geneos components use the JAVA_HOME environment variable (not JRE_HOME) to point to the Java runtime installation directory. For guidance on how to specify JAVA_HOME per platform, see Set the environment variables.

  3. Java executable — On Windows, the Netprobe will attempt to locate Java home using the Java executable configured in the PATH environment variable.

    On Linux, the Netprobe will attempt to locate Java home using the default Java executable configured or symbolic-linked to /etc/alternatives/java. Otherwise, it will locate using the Java executable configured in the PATH environment variable.

    This is not applicable to the IBM AIX operating system.

  4. Default Java installation directories — The Netprobe will recursively locate a usable JRE to be used in the default Java installation directories. On Windows, the directory is C:\Program Files\Java\. On Linux, it is /etc/alternatives.

    This is not applicable to the IBM AIX operating system.

Note

  • The minimum Java version required is Java 8. For guidance, see Java support.
  • Java home set by either using the Java executable or the default Java location will only be used by the Netprobe internally and won’t affect any environment variables.

Set the environment variables Copied

Once the required files are in place, the next step is to set the environment variables so that the Netprobe can locate them.

Note

Beginning Netprobes version 4.12.0, you only need to set the JAVA_HOME environment variable. From the information carried by that variable, the Netprobe can look for other JAR and library files on its own. For more information on this behaviour, see Locating resource files for Netprobe versions 4.12.x.

Locating resource files for Netprobe versions 4.12.x Copied

Beginning Netprobes version 4.12.0, the Netprobe attempts to locate JAR and library files based on the directory set in JAVA_HOME:

With this behaviour in place, the following environment variables become optional:

Instead, the Netprobe searches for the JAR and library files in the following manner:

If the Netprobe fails to locate the files in this method, then it attempts to search the files using the optional environment variables.

Note

If you are running a plugin that requires vendor-specific JAR files, set GENEOS_JARS to point to the directory containing them. For guidance, see For the JAR files.

Java library Copied

The Netprobe needs to create a Java virtual machine from which to load and run Java-based plugins or processes. To do so, it must locate the requisite library file found in the Java runtime installation directory:

To direct the Netprobe to the library file, modify the environment variable accordingly:

When modifying the path environment variable, follow these guidelines:

On Windows Copied

Via command line Copied

You can set the environment variable on the command line:

set JAVA_HOME=C:\Program Files (x86)\Java\jdk1.8.0_211\jre
set PATH=%JAVA_HOME%\bin\client;%PATH%
Via registry Copied

Alternatively, to prevent conflicts with other Java applications, you can set the Netprobe registry keys, instead. The path to the Netprobe registry is HKEY_LOCAL_MACHINE\SOFTWARE\NetAgent\NetprobeNT .

The JAVA_HOME and JVM_LIBPATH keys should be added in the same location as the other Netprobe registry keys:

Windows registry keys for Java resources

Note

If you set the registry keys, then the Netprobe ignores the values set in the environment.

On Solaris Copied

You can set the environment variables on the command line:

setenv JAVA_HOME /usr/java/jdk1.8.0_211/jre
setenv LD_LIBRARY_PATH $JAVA_HOME/lib/sparc/client
setenv PATH $JAVA_HOME/bin:$PATH

On Linux Copied

You can set the environment variables on the command line:

setenv JAVA_HOME /usr/java/jdk1.8.0_211/jre
setenv LD_LIBRARY_PATH $JAVA_HOME/lib/amd64/server
setenv PATH $JAVA_HOME/bin:$PATH

On IBM AIX Copied

You can set the environment variables on the command line:

setenv JAVA_HOME /usr/java8/jre
setenv LIBPATH $JAVA_HOME/lib/ppc:$JAVA_HOME/lib/ppc/j9vm
setenv PATH $JAVA_HOME/bin:$PATH

JAR files Copied

You can specify the directory where the Netprobe accesses the Geneos JAR files through the GENEOS_JARS environment variable.

If a plugin requires vendor-specific JAR files, then use GENEOS_JARS to point to that directory, as well.

On Windows Copied

On Windows platforms, you can set the environment variable on the command line:

set GENEOS_JARS=C:\Jars

On Linux, Solaris, and IBM AIX Copied

On Linux and similar platforms, you can set the environment variable on the command line:

setenv GENEOS_JARS /jars

Note

This setting is particularly useful when a plugin is expected to connect to an application and needs multiple JAR files to be able to connect to it, as it is not always feasible to copy additional JAR files into the current working directory.

Additional directories to shared libraries Copied

To specify additional directories for locating libraries used by the plugin, use the GENEOS_LIBS environment variable.

On Windows Copied

You can set the environment variable on the command line:

set GENEOS_LIBS=C:\Libs

On Linux, Solaris, and IBM AIX Copied

On Linux and similar platforms, you can set the environment variable on the command line:

setenv GENEOS_LIBS /libs

After you set the environment variables, restart the Netprobe.

Next steps Copied

After you have configured the Java environment, you may proceed to setting up your Java-based plugin:

If you encounter errors when configuring your Java environment, see Troubleshoot the Java configuration.

["Geneos"] ["Geneos > Netprobe"] ["User Guide"]

Was this topic helpful?