@After
  public void tearDown() throws Exception {
    TEST_UTIL.shutdownMiniCluster();
    if (rst != null && rst.getRegionServer() != null) {
      rst.getRegionServer().stop("end of test");
      rst.join();
    }
  }
Test metrics incremented on region server operations.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestClusterId.java