@Override
  protected void
    preBalanceCluster(Map<TableName, Map<ServerName, List<RegionInfo>>> loadOfAllTable) {
    // We need clusterLoad of all regions on every server to achieve overall balanced
    setClusterLoad(loadOfAllTable);
  }
Pass RegionStates and allow balancer to set the current cluster load.
hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.java