You can view slow running or stuck Java threads in Trace Explorer.

Application Performance Monitoring provides visibility into slow running or stuck Java threads. The APM Java agent and the APM Java tracer create timed-out spans for threads that do not complete the execution of a request within a defined time period (default time is 60 seconds). The spans dimension values are similar to the standard span with the exception of the OperationName dimension, which is prefixed with TimedOut and the span Kind dimension, which is set to TIMED_OUT. For example, [TimedOut] /frontStore/login.

You can also use this capability in conjunction with Thread Snapshots to identify the class/method/line number on which the Java thread is stuck. For information on the Thread Snapshot view, see View Thread Snapshots.

For information on how to enable, disable, and other configuration options such as changing the default time period for this capability, see the AgentConfig.properties file in the Agent config directory.