I understand that I can do VaadinSession.getCurrent().close() after forwarding to a logout page with a logout button but what do I do if I fire an employee (user) under my account and want their session to be terminated right away? In other words how can the Admin for an account force any sessions for fired users to be terminated ASAP.
If you don’t use clustering, then you can simply maintain a thread-safe list of weak references to all VaadinSessions, registering them on create and unregistering them on destroy. Something akin to this:
https://stackoverflow.com/questions/24995677/how-to-get-all-sessions-in-vaadin
. Then, you can simply enumerate the list, and close all sessions for particular user. Thread safety is important to avoid race conditions.
If you use clustering, I’d employ a broadcast solution which would send a request message to every node; every node can then walk its own list of VaadinSessions and close them accordingly.