Question

I have an xmpp/ejabberdb app that uses an external service to provide eventing features, but when this service becomes unavailable, I want to disconnect/logout all of my clients. Is this possible? How?

Answer 1

I got it working the way I needed. In fact, I didn’t find any simple way to make my own server logout all connected users given some kind of situation, so I dug into ejabberd’s code and figured out a way to do it myself.

In ejabberd_c2s.erl module, when a client logs out or it’s socket is dropped for some reason, the FSM is terminated, doing all necessary clean up to maintain ejabberd’s consistency.

What I had to do was just create an exported function shutdown/1 in this module that calls gen_fsm:send_all_state_event/2 sending a signal for it to terminate.
As for each connection there’s one c2s process, I need to call this function for each user.

—UPDATING—
Actually there’s no need to create this shutdown function, as ejabber_c2s already has the ability to process ‘closed’ signal, which does the same thing. So, instead of creating the shutdown function, simply doing ge_fsm:send_event(C2SPid, closed) might be enough.
—UPDATING—

To discover the user’s c2s process PID I just use ejabberd_sm:get_session_pid/1 or ejabberd_sm:dirty_get_sessions_list/0 (for all sessions).

This worked fine for me, but if anyone has a better idea, please add here.

Thanks