Use
You can use the
workload monitor (Transaction ST03N) to display spool statistics for the application servers in your SAP System.The spool statistics are useful for spool administrators who want to check what has been output in each application server, the number of dialog steps and so on.

The Spool statistics
Procedure

If no spool statistics are available for a specific application server, the system does not display the icon for the Spool statistics.