@Test
  public void testBoundsGreaterThanDefault() throws Exception {
    final int temp = CONF.getInt(BoundedGroupingStrategy.NUM_REGION_GROUPS,
      BoundedGroupingStrategy.DEFAULT_NUM_REGION_GROUPS);
    try {
      CONF.setInt(BoundedGroupingStrategy.NUM_REGION_GROUPS, temp * 4);
      final String parallelism = Integer.toString(temp * 4);
      int errCode =
        WALPerformanceEvaluation.innerMain(new Configuration(CONF), new String[] { "-threads",
          parallelism, "-verify", "-noclosefs", "-iterations", "3000", "-regions", parallelism });
      assertEquals(0, errCode);
    } finally {
      CONF.setInt(BoundedGroupingStrategy.NUM_REGION_GROUPS, temp);
    }
  }
Make sure we can successfully run with more regions then our bound.
hbase-diagnostics/src/test/java/org/apache/hadoop/hbase/wal/TestBoundedRegionGroupingStrategyUsingWPETool.java