public void shutdownMiniDFSCluster() throws IOException {
    if (this.dfsCluster != null) {
      // The below throws an exception per dn, AsynchronousCloseException.
      this.dfsCluster.shutdown();
      dfsCluster = null;
      // It is possible that the dfs cluster is set through setDFSCluster method, where we will not
      // have a fixer
      if (dfsClusterFixer != null) {
        this.dfsClusterFixer.shutdown();
        dfsClusterFixer = null;
      }
      dataTestDirOnTestFS = null;
      CommonFSUtils.setFsDefault(this.conf, new Path("file:///"));
    }
  }
Shuts down instance created by call to {@link #startMiniDFSCluster(int)} or does nothing.
hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtil.java