Sun Java System Web Server 6.1 SP11 Administrator's Guide

Configuring JVM Settings

Unlike previous releases of the product, the Sun Java System Web Server 6.1 no longer supports the standalone Java Runtime Environment (JRE). Instead, JDK 1.4.1 or higher is a pre-requisite for the server. When you install the server, if you select the default JDK option ,Java Development Kit (JDK) version 1.4.1_03 is installed in the <server-root>/bin/https/jdk directory.

You can configure Java Virtual Machine (JVM) settings for your server instance. These settings include the location of your Java home, compiler options, debugging options, and profiler information. One reason to configure these settings is to improve performance. For more information on performance see the Sun Java System Web Server 6.1 SP11 Performance Tuning, Sizing, and Scaling Guide.

Configuring General Settings

To edit the location of the JDK and to specify debug options perform following steps:

ProcedureTo edit the location of the JDK and to specify debug options

  1. Access the Server Manager and choose the Java tab.

  2. Click JVM General.

    Figure 12–2 The JVM General Interface

    The JVM General Interface

  3. Set the Java Home.

    The Java Home is the path to the directory where the Java Developer’s Kit (JDK) is installed. Sun Java System Web Server supports the Sun JDK 1.4.1_03.

  4. Choose whether to enable debugging and set debug options.

    A list of debug options is available at:

    http://java.sun.com/products/jpda/doc/conninv.html#Invocation

  5. Click OK.

Configuring Path Settings

You might want to configure JVM path settings for certain reasons. For example, you want to choose a suffix for the system’s classpath in order to override system classes such as the XML Parser classes, or you want to ignore the environment classpath to prevent environment variable side effects on a production environment.

To configure the JVM’s path settings in the Administration interface, perform the following tasks

ProcedureTo configure the JVM's path settings in the Administration interface

  1. Access the Server Manager and choose the Java tab.

  2. Click JVM Path Settings.

  3. Choose a suffix for the system’s classpath

  4. Choose whether to ignore the environment classpath.

    If you do not ignore the classpath, the CLASSPATH environment variable is read and appended to the Sun Java System Web Server classpath. The CLASSPATH environment variable is added after the classpathsuffix, at the very end.

    For a development environment, the classpath should be used. For a production environment, this classpath should be ignored to prevent environment variable side effects.

  5. Set a native library path prefix and suffix.

    The native library path is the automatically constructed concatenation of the Web Server installation relative path for its native shared libraries, the standard JRE native library path, the shell environment setting (LD_LIBRARY_PATH on UNIX), and any path specified in the profiler element. It does not appear explicitly in the server configuration, because the native library path is synthesized

  6. Click OK.

Configuring JVM Options

To set JVM command-line options in the Administration interface, perform the following tasks

ProcedureTo set JVM command-line option in the Administration interface

  1. Access the Server Manager, and choose the Java tab.

  2. Click JVM Options and make the necessary changes.

    For information about specific JVM options, see:

    http://java.sun.com/docs/hotspot/VMOptions.html

  3. Click OK.

Configuring the JVM Profiler

You can use a profiler to perform remote profiling on the Sun Java System Web Server to discover bottlenecks in server-side performance.

To configure the JVM Profiler in the Administration interface, perform the following tasks

ProcedureTo configure the JVM Profiler in the Administration interface

  1. Access the Server Manager, and choose the Java tab.

  2. Click JVM Profiler.

  3. Specify the classpath, the native library path, and whether the profiler is enabled.

  4. Add, delete or edit JVM options for the profiler, and click OK.

    For more information about profilers, see the Sun Java System Web Server 6.1 SP11 Programmer’s Guide.