Is it possible to set an alert to monitor the number of named users in Portal for ArcGIS? I can see the number of portal users in ArcGIS Monitor Server > Site > Catalog but it would be useful to alert administrators if the number of users is close to the maximum named users allowed in the license file. For example, if portal is set to 'automatically join' to provide a seamless login experience, the named user limit will eventually be reached due to staff turnover. The alert could then prompt the administrator to review the users and or delete inactive users/users who haven't logged in for x weeks.
The listing of users is metadata for the administrator to consider. But the user count is not tracked as a counter as of ArcGIS Monitor 10.8.1. For this reason, an alert is not possible at this time. Future versions of ArcGIS Monitor will consider this as a feature request. Thanks for the question and feedback.