Currently in MR-279 the Auxiliary services, like ShuffleHandler, have no way to communicate information back to the applications. Because of this the Map Reduce Application Master has hardcoded in a port of 8080 for shuffle. This prevents the configuration "mapreduce.shuffle.port" form ever being set to anything but 8080. The code should be updated to allow this information to be returned to the application master. Also the data needs to be persisted to the task log so that on restart the data is not lost.