internal       (on|off)    set to 'on' for exchange to be not used directly by publishers, but only when bound to other exchanges
auto_deleted   (on|off)    auto delete queue when set to 'on', when there are no consumers
delivery_mode  (number)    set to '1' for non-persistent or '2' for persistent queue
queue_dir      (path)      staging dir for undelivered messages e.g. '/home/events'