Oracle Cloud Infrastructure Documentation

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 Management Agent and Deploying JMS Plug-ins.
  • 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.
    Note

    Java Usage tracker properties file is truncated once usage reports are successfully sent to JMS Fleets.
    Additionally, JMS plugins 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 Fleets because they don’t have usage tracker capabilities.
    JMS plugin 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 plugins 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 Management Agent and Deploying JMS Plug-ins.