JEUS

Adding JVM options

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

1. Refer to the path of the configuration file for startup options depending on the JEUS version, and then add the -javaagent option.

   JEUS 7

   $JEUS_HOME/domains/jeus_domain/config.xml

   <domain>
       <servers>
           <server>
               <name>server1</name>
               <jvm-config>
                   <jvm-option>
                       -Xmx1024m -XX:MaxPermSize=128m
                       -javaagent:/whatap/whatap.agent-X.Y.Z.jar
                   </jvm-option>
               </jvm-config>
           </server>
       </servers>
       ...
   </domain>

   JEUS 6

   $JEUS_HOME/config/$hostname/JEUSMain.xml

   <node>
       <name>node01</name>
       <engine-container1>
           <name>container1</name>
           ...
           <command-option>-Xmx1024m -XX:MaxPermSize=128m
               -javaagent:/whatap/whatap.agent-#.#.#.jar
           </command-option>
           ...
       </engine-container1>
   </node>

2. Restart the application server.

   jdown && jboot

3. Through the application server log file and the agent log file, check whether the agent is operating normally or any error occurs. For the location of log files, see the following:

   • Agent: $WHATAP_HOME/logs/whatap-{SERVER_NAME}-{DATE}.log
   • JEUS 7: $JEUS_HOME/domains/$HOST_NAME/servers/$NODE_NAME/logs/JeusServer.log
   • JEUS 6: $JEUS_HOME/logs/$NODE_NAME/JeusServer.log

4. Check whether the agent has recognized the application server type and service container name.

Note

Log in Whatap Monitoring Service and then select a project. Select Application > Instance performance analysis, and then select the Runtime boot environment tab. Check the whatap.name and whatap.type entries. The last element of the whatap.name entry must be the container name. The application server's type must be specified in the whatap.type field.

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.

Next steps

• Open source tracing

  Depending on the framework or open source library used in applications, you may need to add agent options. For example, when using spring-boot-3.x, feign-client-11, or okhttp3-4.4 with a framework or open source, set the options as follows:

  whatap.conf

  weaving=spring-boot-3.0,feign-11,okhttp3-4.4

  For information on how to configure the framework or open source library that suits your application environment, see the following.

• Checking the installation

  If you have created a project, installed an agent, and applied all JVM options, see the checklist in the following.

• Installation troubleshooting

  It provides various problems that may occur when installing the agent and specific instructions for resolving them. It provides solutions against various situations, including firewall configuration, SpringBoot and Tomcat JMX configuration, and server configuration using the OSGI framework. For more information, see the following.

• Agent setting

  It provides various features for monitoring by applying some options to the agent configuration file (whatap.conf). It includes basic configuration, configuration for server connection and data transfer, how to manage the configuration files for multiple application servers, and transaction tracing, and more. For more information, see the following.

• Starting the monitoring

  After all settings are made, restart the application server. The agent starts collecting data. First, check whether the monitoring data has been collected in Application Dashboard. For more information about Application Dashboard, see the following.