Tracing of JES2 processing is done by activating IBM® or installation trace points in the code. Trace points may be put into the code to save register contents and data. Initialize tracing by specifying parameters on the TRACE(n), TRACEDEF, SSI(n), and device initialization statements. Traced data can be accessed in formatted system output and through a dump of unformatted trace tables residing in CSA storage.

Enter the $T TRACEDEF command to start the trace facility. This command allows you to specify the JES2 environment characteristics. The $S TRACE(n) and $P TRACE(n) allow you to activate and deactivate specific trace identifiers, which relate to events to be traced. For a list of the trace identifiers and their associated meanings, see z/OS JES2 Diagnosis, GA32-0993.

You can trace all processors of a given type using the $T PCE command. This command allows you to start or stop tracing for a particular processor. The $D PCE command displays the tracing status for JES2 processors.

To start or stop tracing for a subsystem interface function, enter the $T SSI(n) command. For more information about the SSI functions that are intended for customer use, and their associated meanings, see z/OS MVS Using the Subsystem Interface, SA38-0679.