Troubleshooting#

The agent writes its messages to standard error, starting with [verbatime].

The JVM stops at startup#

An agent option is invalid. The line starting with [verbatime] WARN invalid agent arguments: says what to fix. See Agent options.

The Verbatime views do not appear#

Check that verbatime-jmc-plugin.jar is in the dropins directory, then start JDK Mission Control once with -clean. Do the same when a new version of the plugin does not take effect.

JDK Mission Control cannot connect#

The Control view shows Connection failed or Connection timed out.

• Check that the application runs with both the agent and the JMX flags.
• For a container or another host, see From a container or another host.

A recording has no sessions#

• The root did not run while recording. Send the request or run the job after Start recording. A call already running when recording starts is not recorded.
• The root name does not match. A root whose dot stays yellow after its code has run matches no method. With roots=, the agent logs [verbatime] WARN root ... never matched a loaded method when the JVM exits. Check the class and method name, and write nested classes as Outer$Inner.

No recording file after the JVM exits#

• The directory in out= must exist. If not, the agent logs a warning at startup and records nothing.
• Without out=, the recording is deleted when the JVM exits. See Limitations.
• With Maven, Surefire must fork the tests. forkCount=0 ignores argLine.