It is an attempt to understand what is dpmon and its use.
DPMON is a tool provided by SAP to use from the operating system. This is similar to work process overview like SM50 or SM66.
This tool is of great help when for some reason we are not able to login through SAP GUI. We can identify the issue by logging into the operating system and use dpmon.
(On a redhat linux operating system)
Login to the central instance host of the SAP system using <sidadm> user id.
Go to the profiles directory using
cd /usr/sap/<SID>/SYS/profile (or)
cd /sapmnt/<SID>/profile (or)
use dpmon pf=<profilename>
Will get a display “Dispatcher Queue Statistics” . We can see if any dispatcher waits are there.
dispatch monitor menu is listed. type l view the work process overview.
If all the work processes are full take the PID of the work process having problem and kill using the OS level command Kill -9 <PID>..
After this we can login to the system through SAPGUI.