Minor Description
Currently there is only one configuration knob available for controlling the number of mappers per job in HBase Streaming. The current option is number of mappers per region. This options tries to maintain the locality for the mapper and the region servers.
However, in certain certain scenarios where the table has a higher number of regions, the number of mapper/region can lead to explosion of the number of mappers. Hence, we need one more option to control the strict number of mappers per job.