Transaction code SM51 is to display list of active application servers that have registered in the SAP message server. Further, you can manage & display the status, users, work process in all application servers belonging to the SAP System.
• Processes: Display & control work process. [SM50]
• User: Display & manage user sessions. [SM04]
• SNC Status: Display SNC status.
• Release Notes: Display detailed release information for an application server.
• Remote Logon: Log on by any server in the system; you can see the server where you are logged on in the status bar in the second entry from the left.
• System Log: System logs. [SM21]