Tuning HBase Prior to Decommissioning DataNodes
To increase the speed of a rolling restart of the HBase service, set the Region Mover Threads property to a higher value.
Minimum Required Role: Configurator (also provided by Cluster Administrator, Full Administrator)
This increases the number of regions that can be moved in parallel, but places additional strain on the HMaster. In most cases, Region Mover Threads should be set to 5 or lower.