1 What's New in JDK Mission Control 9

JDK Mission Control (JMC) is an advanced set of tools for managing, monitoring, profiling, and troubleshooting Java applications. JMC enables efficient and detailed data analysis for areas such as code performance, memory, and latency without introducing the performance overhead normally associated with profiling and monitoring tools.

The following are some of the new features introduced in JMC 9:

  • Reduced allocations in the JMC parser have significantly improved JFR parser performance, including reduction in Doubles and allocation rate in ParserStats. Binary search has also improved the speed of linear time reordering and linear lane search.
  • Search by event type IDs is now enabled and is displayed in a column (hidden by default) next to the event ID.
  • JMC can now start flightrecorder on GraalVM native image.
  • To improve the performance and efficiency of the flamegraph visualization, a Java Swing based framework is now used. In addition, the performance of flame graph model creation has been improved.
  • A new field has been added to specify the scan frequency of the JVM browser to monitor JVMs. To update the scan frequency:
    • In Windows, go to Windows, Preferences, JDK Mission Control, JVM Browser, and then Local.
    • In macOS, go to JDK Mission Control, Settings, JDK Mission Control, JVM Browser, and then Local.
    Enter the required scan interval in JVM Browser Refresh Interval (ms) field.
  • JMC 9 now supports dark mode. Go to Preferences, General, Appearance, and select the Dark theme to enable.
  • New rule is added to use the jdk.FinalizerStatistics JFR event. This event helps to determine where the finalizers, which have been deprecated for removal in a future release, are run in your application.
  • New rule is added to display G1 MMU information. It compares the pause time targets with the actual pause time and provides a warning message if it exceeds the pause target.
  • A new rule has been added to JMC to detect Inverted Parallelism in GC. The new rule makes use of the new GC CPU time JFR event, which has been introduced in JDK 20. See Add rule to detect GC Inverted Parallelism for more information.
  • The Percentage (by Duration) column is added in the Stack Trace tab. It displays the percentage of aggregate duration (in time unit).
  • Automated analysis now displays the reason for all Ignored Rules, helping to clearly understand the reason behind missing events.
  • Stack traces can be exported in collapsed format. Right-click the stack trace you wish to export, select Export stacktraces and Collapsed.
  • JMC is now supported on Linux aarch64 platform.
  • Due to changes in the APIs provided by Twitter, the JMC plug-in for Twitter has been removed.