How to find out how many users are currently using Vault?

[erict]

Is there a surefire way to determine how many people are currently using Vault? In Admin | Users it shows everybody logged on, even though I know a few who definitely are not. So it must be 'logged-on' until session time-out, which I had to set to large number to avoid constant 'session time-out please log-in again'.
I now want to reboot the server but don't want to interrupt anybody's work. Is there anything I can query in the database or some other way?

Thanks,
Eric T.

[jclausius]

Unfortunately, no. IIS is in charge of sessions - which controls what the Admin Tool reports as logged in.

However, assuming everyone shuts down properly, this list should be accurate.