WebSphere Message Broker, Version 8.0.0.7
Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS
See information about the latest product version
See information about the latest product version
JVM parameter values
Select the objects and properties associated with the Java™ Virtual Machine (JVM) that you want to change.
To change these properties, you must specify the broker name, and set the ObjectName to ComIbmJVMManager. If you are setting a debug port number, you must also include -e and specify the name of the execution group which will use the port.
- -n jvmMinHeapSize
- The minimum size of the storage available to the
JVM, specified in bytes.
- Value type: integer
- Initial value: -1, which represents 33554432 bytes (32MB) with the global cache disabled, or 100663296 (96MB) with the global cache enabled
- -n jvmMaxHeapSize
- The maximum size of the storage available to the
JVM, specified in bytes. If you have configured a publish/subscribe
domain, when execution groups retain publications, you might need
to increase this value. If you have included the XSLTransform node in one or
more message flows, and the node is processing very large XML messages,
you might also have to change this parameter.
- Value type: integer
- Initial value: -1, which represents 268435456 bytes (256 MB)
- -n jvmDebugPort
- The port on which the execution group is listening. You must set a port number to activate debug in the execution group.
- Value type: integer
- Initial value: 0
Warning: When the jvmDebugPort is enabled, a remote user can connect to the broker's JVM and inspect its behavior and data, including potentially sensitive information. A remote user can also exert control over the broker's behavior. It is therefore recommended that the jvmDebugPort is disabled on production systems. - -n jvmNativeStackSize
- The maximum stack size for Java threads.
- Value type: integer
- Initial value: -1, which represents 1048576 bytes (1 MB) on Solaris and Linux platforms, otherwise the value is JVM dependent
- -n jvmJavaOSStackSize
- The default stack size for Java Operating
System threads. If you have a message flow with large number of nodes
between two nodes written in Java (for
example, JavaCompute nodes
or Java user-defined nodes),
you might have to increase the size of this parameter.
- Value type: integer
- Initial value: JVM dependent
- -n jvmSystemProperty
- The value of this property defines Java system properties for an execution group that can be used by JavaCompute nodes. The format is in the form -Dname1=value1. You can set multiple properties in the following way:
-v"-Dname1=value1 -Dname2=value2"
Note: As shown in this example, there must not be a space character after the -v parameter.- Value type: integer
- Initial value: JVM dependent
- -n jvmVerboseOption
- The value of this property identifies the type of Java verbose information that is displayed for
an execution group.
- Value type: string
- Initial value: none
- Other valid values:
- class: display information about each class loaded
- jni: display information about use of native methods and other Java Native Interface activity
- gc: display information about each garbage collection event
- all: display information for all of the verbose options
See the mqsichangeproperties command for examples of how to change parameters for the JVM. Other examples are provided for particular tasks: