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WebLogic

Adding JVM options​

This guide explains how to add required JVM options to effectively use the Java monitoring agent in the WebLogic application server environment.

Check the OS and then complete the configuration.

{WebLogic_Path}/user_projects/domains/{User_Domain}/bin/startWebLogic.bat
rem ########## WHATAP START ############
set WHATAP_HOME=\path\to\whatap
for /f %%f in ('dir /b /on "%WHATAP_HOME%\whatap.agent-*.jar"') do set last=%%f
set WHATAP_JAR=%last%
set WHATAP_OPTS=-javaagent:%WHATAP_HOME%\%WHATAP_JAR%
if "x%JAVA_OPTIONS%"=="x" goto setWhatap
set JAVA_OPTIONS_TMP=%JAVA_OPTIONS:"=%
if not "x%JAVA_OPTIONS_TMP:whatap=%"=="x%JAVA_OPTIONS_TMP%" goto endWhatap
:setWhatap
set JAVA_OPTIONS=%JAVA_OPTIONS% %WHATAP_OPTS%
:endWhatap
rem ########## WHATAP END ############
Note

In case of Java 17 or later, add the following options for reflection.


--add-opens=java.base/java.lang=ALL-UNNAMED

Viewing the heap histogram​

WhaTap's Java Monitoring provides the function to view the status of heap occupancy objects in the JVM memory (sizes for each object in heap memory). In APP > Instance performance analysis, select the Heap histogram tab.

Java versions 6 to 8 support basic functions without the JVM options. However, for some Java versions, the JVM options must be applied as follows:

  • Java 9 to Java 15

    -Djdk.attach.allowAttachSelf=true
    example
    java -javaagent:{WHATAP_HOME}/whatap.agent-X.Y.Z.jar -Djdk.attach.allowAttachSelf=true -jar {application.jar}

  • Java 16 or later

    -Djdk.attach.allowAttachSelf=true
    --add-opens=jdk.attach/sun.tools.attach=ALL-UNNAMED
    example
    java -javaagent:{WHATAP_HOME}/whatap.agent-X.Y.Z.jar -Djdk.attach.allowAttachSelf=true --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=jdk.attach/sun.tools.attach=ALL-UNNAMED -jar {application.jar}
Note

It does not support Java 5 or earlier and IBM Java.

Starting the monitoring​

Once the application server is restarted after configuring all settings, the agents start collecting data. See the following.