@Test
  public void test() throws InterruptedException {
    RegionServerThread t = UTIL.getMiniHBaseCluster().stopRegionServer(0);
    t.join();
  }
Testcase to confirm that we will not hang when shutdown a cluster with no live region servers.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestShutdownWithNoRegionServer.java