Administer Java virtual machine settings

The Java virtual machine settings for your application server specify Java virtual machine system properties that your applications use.

You can use the administrative console and wsadmin to configure Java virtual machine settings.

Use the administrative console to administer Java virtual machine settings

To administer Java virtual machine settings with the administrative console, follow these steps:

  1. Start the administrative console.

  2. Expand Servers and click Application Servers.

  3. Click the name of your application server.

  4. On the application server's page, click Process Definition.

  5. On the Process Definition page, click Java Virtual Machine.

  6. Configure settings for the Java virtual machine.

  7. Click Apply or OK.

  8. Save the application server configuration.

Use wsadmin to administer Java virtual machine settings

To administer Java virtual machine settings with wsadmin, follow these steps:

    On the CL command line, run the STRQSH (Start Qshell) command.

    Run the cd command to change to the directory that contains the wsadmin tool: 

    cd /QIBM/ProdData/WebASE51/ASE/bin

    Start wsadmin.

    At the wsadmin prompt, run this command to identify the application server and assign it to the server variable: 

    set server [$AdminConfig getid 
/Cell:myCell/Node:myNode/Server:myAppSvr/]

    where myCell is the name of the cell that contains your application server, myNode is the name of the node that contains your application server, and myAppSvr is the name of your application server.

    This command has been wrapped for display purposes.

    Run this command to identify the Java virtual machine for your application server and assign it to the jvm variable: 

    set jvm [$AdminConfig list JavaVirtualMachine $server]

    Use the attributes command to display a list of the attributes that you can set for the Java virtual machine: 

    $AdminConfig attributes JavaVirtualMachine

    The command displays this output: 

    "bootClasspath String*"
"classpath String*"
"debugArgs String"
"debugMode Boolean"
"disableJIT Boolean"
"executableJarFileName String"
"genericJvmArguments String"
"hprofArguments String"
"initialHeapSize Integer"
"maximumHeapSize Integer"
"osName String"
"runHProf Boolean"
"systemProperties Property(TypedProperty)*"
"verboseModeClass Boolean"
"verboseModeGarbageCollection Boolean"
"verboseModeJNI Boolean"

    Modify the Java virtual machine attributes. For example, to turn on debugging, run this command: 

    $AdminConfig modify $jvm {{debugMode true} {debugArgs "-Djava.compiler=NONE -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=7777"}}

    Run this command to save your changes: 

    $AdminConfig save