@Before
  public void before() throws Exception {
    UTIL.getConfiguration().set("hbase.master.loadbalancer.class", this.balancerName);
    // set minCostNeedBalance to 0, make sure balancer run
    UTIL.startMiniCluster(1);

    this.tableDescriptor = TableDescriptorBuilder.newBuilder(TableName.valueOf("test"))
      .setColumnFamily(ColumnFamilyDescriptorBuilder.of(FAMILY_NAME)).build();
  }
Test whether region re-balancing works. (HBASE-71) The test only works for cluster wide
balancing, not per table wide. Increase the margin a little to make StochasticLoadBalancer result
acceptable.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestRegionRebalancing.java