private void addAuthInfoToConf(Properties authConfig, Configuration conf, String owner,
    String userList) throws IOException {
    List<String> users = new ArrayList<>(Arrays.asList(userList.split(",")));
    users.add(owner);
    for (String user : users) {
      String keyTabFileConfKey = "hbase." + user + ".keytab.file";
      String principalConfKey = "hbase." + user + ".kerberos.principal";
      if (!authConfig.containsKey(keyTabFileConfKey) || !authConfig.containsKey(principalConfKey)) {
        throw new IOException("Authentication configs missing for user : " + user);
      }
    }
    for (String key : authConfig.stringPropertyNames()) {
      conf.set(key, authConfig.getProperty(key));
    }
    LOG.debug("Added authentication properties to config successfully.");
  }
Check for errors in the writer threads. If any is found, rethrow it.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/util/LoadTestTool.java