Our application is using Symfony 2.0 and MongoDB with FOSUserBundle for user management.
Client wants to prevent login with the same username from different device at the same time in their application.
Our idea is to invalidate/delete all other sessions for the same user when the successful login occurs.
The problem is, that we cannot save session in DB, because Mongo Session handler was added later in the version 2.1.
The only solution we come up with is to iterate over the session files saved in file-system and check if the username of the user is saved in that file. If that is true, we just delete the file and login session on other locations are terminated. Of course we have to check that we don't delete the current session also.
Does anyone have a better idea how the problem could be solved? If not, are there any hidden traps that we should know about?