@Test
  public void testMasterZKSessionRecoveryFailure() throws Exception {
    LOG.info("Starting " + name.getMethodName());
    SingleProcessHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
    HMaster m = cluster.getMaster();
    m.abort("Test recovery from zk session expired", new KeeperException.SessionExpiredException());
    assertTrue(m.isStopped()); // Master doesn't recover any more
    testSanity(name.getMethodName());
  }
Master recovery when the znode already exists. Internally, this test differs from
{@link #testMasterSessionExpired} because here the master znode will exist in ZK.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java