@Override
  public void setConf(Configuration conf) {
    super.setConf(conf);
    Path rootDir;
    try {
      rootDir = CommonFSUtils.getRootDir(conf);
      rootDir.getFileSystem(conf);
    } catch (IOException ex) {
      throw new RuntimeException(ex);
    }
  }
A simple performance evaluation tool for single client and MR scans and snapshot scans.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/ScanPerformanceEvaluation.java