@Override
  protected Logger getLogger() {
    return LOG;
  }
Unbalances the regions on the cluster by choosing "target" servers, and moving some regions
from each of the non-target servers to random target servers.
@param fractionOfRegions Fraction of regions to move from each server.
@param fractionOfServers Fraction of servers to be chosen as targets.
hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/UnbalanceRegionsAction.java