public double getOrComputeWeightedLocality(int region, int server,
    BalancerClusterState.LocalityType type) {
    return getRegionSizeMB(region) * getOrComputeLocality(region, server, type);
  }
Returns locality weighted by region size in MB. Will create locality cache if it does not
already exist.
hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/BalancerClusterState.java