public void setServerSessionTimeout(int timeout) {
        if (getServerSessionTimeout() == timeout) {
            return;
        }
        // Set the new property value
        JiveGlobals.setProperty("xmpp.server.session.timeout", Integer.toString(timeout));
    }
Sets the number of milliseconds to elapse between clearing of idle server sessions.

@param timeout the number of milliseconds to elapse between clearings.
xmppserver/src/main/java/org/jivesoftware/openfire/SessionManager.java