This chapter describes common problems that you might encounter when installing or using Java Management Service and explains how to diagnose and resolve them.

See also Troubleshoot Management Agent Installation Issues.


If the problem still persists or if the problem you're facing isn't listed, refer to the Getting Help section of this document.

Java Runtime usage isn't captured in the fleet

This may be the caused by one of the following:
  • See this A Java runtime may initially be absent from the table.
  • Check which directories on your host will be scanned to discover installations of Java Runtimes. See the steps to customize the directories that are scanned by the agent in Installing a Management Agent.
  • You're using an older Java release.
    Java Management Service relies on the Java Usage Tracker to report Java usage. The Java Usage Tracker tracks how Oracle Java Runtime Environments are being used in your systems and captures the JRE version, vendor, the application being run, and other details.

    Java Usage tracker properties file is truncated once usage reports are successfully sent to JMS.
    Additionally, JMS periodically performs a file scan to detect Java runtimes that aren't captured by the Java Usage Tracker, because they aren't being used or don't have the Java Usage Tracker capabilities. Java Usage Tracker is available for all releases of Java 7, and later, and also for the following older Java releases:
    • 6u25 and later updates

    • 5.0u33 and later updates

    • 1.4.2_35 and later updates

    Oracle Java versions earlier than the ones mentioned above will not have usage reported in JMS because they don’t have usage tracker capabilities.
    JMS generates the usage tracker in the following locations:
    • central location for release 1.8.0_60 and later that supports central usage tracker location. This is done during agent installation.
    • locally for versions earlier than 1.8.0_60 that don't support central usage tracker location. Agents check for older versions periodically and generate local usage tracker properties file for the discovered older Java runtimes.
  • You’re using OpenJDK runtimes.

    JMS detects OpenJDK runtimes through file scanning, but they won't have usage associated because they lack Java Usage Tracker capabilities.

  • Check that you have correctly configured Java Usage Tracker on your host. For more information, see how to configure the Java Usage Tracker in Installing a Management Agent.

A managed instance is absent from a fleet

This may be caused by one of the following:

I can't find my fleet

If you're unable to find a fleet, consider the following troubleshooting approaches.
  • Have you deleted the fleet?

    A deleted fleet is kept for 90 days before it is permanently removed. (See Deleting a Fleet.)

  • Have you selected the appropriate compartment in the Fleet Dashboard?

    (See Viewing Fleets in a Dashboard.)

  • Are you connected to the appropriate OCI region?

    A fleet is a regional resource–this means that you can access it only from the region in which you created it. For example, if you created a fleet in the US East (Ashburn) region, it's not visible from other regions, such as US West (Phoenix). (See Resource Availability.)

I see an unknown application

You may see unknown applications when viewing a table of applications, such as those associated with a managed instance or those that ran on a specific Java Runtime. Each of these is described in the table below.

Application(s) Notes
org.tanukisoftware.wrapper.WrapperSimpleApp This application represents the management agent running on a host.






These applications appear if a management agent has been recently installed or restarted.

I'm unable to install a management agent on my host

This may be caused by the following issues:
  • The clock on your host is not synchronized with the OCI platform. You'll be unable to install a management agent if your host's clock is skewed more than five minutes from the OCI platform. For more information, see Maximum Allowed Client Clock Skew.
  • Ensure you have read the Management Agent documentation and confirm that you meet the prerequisites. In particular, your host must meet the Generic Prerequisites for Deploying Management Agents, including the requirement for JDK 8 (update 281, JDK 1.8.0_281, or higher). The management agent is not compatible with any other versions of the JDK.

The charts are inaccurate

The charts may appear inaccurate if you've recently created a fleet or installed new agents. Change the interval setting from its default (auto) to 1 hour.

The security state of a Java Runtime is absent

The security state is available only for Oracle Java Runtimes.

The vendor name of a Java Runtime is absent

It's not always possible to determine the vendor of a Java Runtime. In such cases, the vendor name is indicated by N/A.

Secure connection between my network and JMS

You might want to transmit to and from JMS (OCI) to your site.

You might want to give your on-premise or OCI network private access to the Oracle Cloud Service. This private access lets your hosts communicate with JMS without passing the information over a public network. Refer to the following articles for more information:

Missing Log Configuration Warning Message and/or Fleet(s) with "Needs Attention" state

JMS uses the OCI Logging service to store inventory and operation logs. While operation logs are optional, inventory logs are required for fleets to function normally. See Log Configuration for details. The Missing log configuration warning message is displayed in the fleet dashboard and the fleet details if logs are not configured or not accessible. This can be caused by:
  • You're using an old fleet for which the log configuration isn't yet enabled.
  • The configured logs of a fleet were disabled or deleted using the OCI logging module.

The state of such fleets is changed to Needs Attention. See Log Configuration Details present in the Fleet Properties Tab of that fleet for more details. To enable logs, click Enable log configuration in the warning message.

My agent isn't working after updating or installing the Java runtime in the managed instance

My agent is not working after updating or installing Java runtime in the managed instance.

There are two possible causes for this issue:
  1. If the Java runtime used by management agents isn't updated according to the instructions in Using Java with Management Agent, your agents will stop working. You'll have to reinstall agents as described in Installing a Management Agent.
  2. If the management agent was set up with system Java, LCM install operation may update the java symlink in alternatives framework and change the default system java path. JMS recommends setting up the management agent with a Java installation that is independent of system java. For example, while installing the management agent, set JAVA_HOME to JDK 8 that is not managed by the operating system's package management system.

Lifecycle Management Work Request Fails With Message "Missing External Plug-in"

You need to have the Java Management Service plugin enabled on your managed instance to perform Java Runtime lifecycle management operations. Follow these steps to enable the plugin in the managed instance.

  1. You have set up the lifecycle management related policies described in Setting Up Oracle Cloud Infrastructure for Java Management Service.
  2. To enable Java Runtime Lifecycle management operations on your compute instance:
    1. For Linux: Sudoers are necessary only for on-prem installations. Edit the /etc/sudoers file and add the following to the end of the file:
      #To change ownership of the Java Management Service plugin to root mgmt_agent ALL=(ALL) NOPASSWD:/opt/oracle/mgmt_agent/agent_inst/bin/ 
      #To run the Java Management Service plugin under root user mgmt_agent ALL=(root) NOPASSWD: ALL
    2. Deploy the service plug-in named Java Management Service, as described in Deploy a Plug-in Using the Agents Page.

Java Runtime Remove Work Request is failing to remove certain runtimes

JMS will not remove the following Java Runtimes from a managed instance:
  • The default Java Runtime
  • The last Java Runtime
  • The Java Runtime used by the Management Agent.

Issues with advanced features

Check the following if you encounter issues with advanced features:

  • Java workloads are running on at least 8u351-b31 or latest
  • Agent is running on JDK; advanced features doesn’t work if the agent is running on JRE instead of JDK
  • You are working on Linux platform; advanced features doesn’t work on Windows