The Wrapper contains support for requesting that the JVM dump out its current state. The exact contents of the information will vary depending on which JVM is being run.
The Sun JVMs will display the stack traces of all running threads to the console.
IBM JVMs provide even more useful information. The stack traces of all threads as well as object monitor states are dumped to the console. In addition a file is created in the current directory which in addition to the information shown in the console also contains useful information about the system including all of the environment variables.
A Thread Dump can be requested on Windows systems by pressing CTRL-BREAK or on Linux systems by pressing CTRL-\. Invoking a thread dump does not affect the JVM. It will continue to run normally.
The startup for Linux and Solaris provided with the Wrapper instalation, launch the Wrapper in a backgroud thread. To request a thread dump using these scripts, simply rerun the script specifying the 'dump' parameter.