You can check the Dynatrace Server log lines to check number of times the user has successfully logged in:
[ClientSessionInitializer] User 'custom_user' logged in successfully (from DT_SERVER_HOSTNAME)
There is actually an out of the box measure available where you can chart the number of users on the Rich Client.
If you go to the 'dynaTrace Self-Monitoring' System Profile and create a custom chart, there is a measure called 'Number of Clients' which will tell you the number of connected clients.
There isn't a measure for the number of logins however. If you are just looking for that, I would recommend you use this plugin -> https://community.dynatrace.com/community/display/...
Hope this helps,
Yes. You will have to go into debug mode (CTRL + SHIFT + F9) but if you go to the Self-Monitoring profile and go to something like Visits, you will see people logging onto your Web UI.
Another similar post for reference -> https://answers.dynatrace.com/questions/183633/monitor-dynatrace-users.html?childToView=184047#comment-184047