SM51 - instances of SAP system - monitoring

 1. Access T-code:SM51.

Check:
1. Check the Application server instance - state as active.
2. During any maintenance activity, we can make state as - Deactivate.
       Goto--> Administration -->state -->Deactivate.

3.after completing maintenance activity, we can make state as - Activate.

       Goto--> Administration -->state -->Activate.

4.To check list of Users in all the clients(100,200 etc.,)
       Goto --> Users.
   Analysis the user load in all the clients.

5.This option lets you make the changes made in the OS hosts and services tables in a running.
    SAP system take effect by making the desired changes at the operating system level and then

      instead of restarting, resetting the host name buffer for the following components.

     SM51 --> Go to -->Host Name Buffer --> Reset --> Entire System.