Sometimes you will find yourself in the situation that you need to stop an SAP Dialog Instance while the Central Instance and Message Server are still running. This can be tricky, but you can avoid any disruptions in service or failed processes if you follow these easy steps:
1. Run transaction SMMS, choose the Dialog Instance you need to stop, and select Goto > Expert Functions > Servers > Deactivate. This will put the instance in passive mode, which prevents any new processes from being started on that instance. This can also be done from transaction SM51 by choosing the instance and selecting Goto > Server Name > Administration > Deactivate.
2. SM66 will now no longer show any active processes on that instance, however this is because your session cannot get to that instance while it is deactivated. You will need to watch the ABAP Work Process Table from the SAP MMC Management Console. When all the processes are idle, then it is safe to stop the instance.
3. Be sure to ONLY stop the dialog instance or you will kill active processes.
Keep in mind if you only have a single Dialog Instance, you will be effectively halting all system access, so it is best to only do this if you have multiple Dialog Instances in you landscape and logon groups.
You will also want to keep in mind that any user sessions already on that instance will still be attached to that instance, so when you stop the instance their sessions will be lost. You will first want to have users connected to that instance log out and back in so that they connect to one of the Active instances.
When you start the instance back up, it should automatically go back into Active mode, so you will just need to verify that in SMMS or SM51.
Hope this helps...
