private void cleanupHbckZnode() {
    try {
      if (zkw != null && hbckZodeCreated) {
        ZKUtil.deleteNode(zkw, hbckEphemeralNodePath);
        hbckZodeCreated = false;
      }
    } catch (KeeperException e) {
      // Ignore
      if (!e.code().equals(KeeperException.Code.NONODE)) {
        LOG.warn("Delete HBCK znode " + hbckEphemeralNodePath + " failed ", e);
      }
    }
  }
This method maintains an ephemeral znode. If the creation fails we return false or throw
exception
@return true if creating znode succeeds; false otherwise
@throws IOException if IO failure occurs
hbase-server/src/main/java/org/apache/hadoop/hbase/util/HBaseFsck.java