If you lower the value of "maxInactivityDuration = 1000" then ActiveMQ figures out faster thata one of the connections is dead and resumes delivery to the others.
maxInactivityDuration default is 30000. The maximum inactivity duration (before which the socket is considered dead) in milliseconds. On some platforms it can take a long time for a socket to appear to die, so we allow the broker to kill connections if they are inactive for a period of time. Use by some transports to enable a keep alive heart beat feature. Set to a value <= 0 to disable inactivity.