apache/beam · error · ValueError

hdfs_user is not set

Error message

hdfs_user is not set

What it means

HadoopFileSystemClients.__init__ resolved no hdfs_user from the pipeline options (neither HadoopFileSystemOptions nor the options dict supplied it), and WebHDFS requests cannot be authenticated on behalf of a user without it.

Source

Thrown at sdks/python/apache_beam/io/hadoopfilesystem.py:138

      raise ValueError('pipeline_options is not set')
    if isinstance(pipeline_options, PipelineOptions):
      hdfs_options = pipeline_options.view_as(HadoopFileSystemOptions)
      hdfs_host = hdfs_options.hdfs_host
      hdfs_port = hdfs_options.hdfs_port
      hdfs_user = hdfs_options.hdfs_user
      self._full_urls = hdfs_options.hdfs_full_urls
    else:
      hdfs_host = pipeline_options.get('hdfs_host')
      hdfs_port = pipeline_options.get('hdfs_port')
      hdfs_user = pipeline_options.get('hdfs_user')
      self._full_urls = pipeline_options.get('hdfs_full_urls', False)

    if hdfs_host is None:
      raise ValueError('hdfs_host is not set')
    if hdfs_port is None:
      raise ValueError('hdfs_port is not set')
    if hdfs_user is None:
      raise ValueError('hdfs_user is not set')
    if not isinstance(self._full_urls, bool):
      raise ValueError(
          'hdfs_full_urls should be bool, got: %s', self._full_urls)
    self._hdfs_client = hdfs.InsecureClient(
        'http://%s:%s' % (hdfs_host, str(hdfs_port)), user=hdfs_user)

  @classmethod
  def scheme(cls):
    return 'hdfs'

  def _parse_url(self, url):
    """Verifies that url begins with hdfs:// prefix, strips it and adds a
    leading /.

    Parsing behavior is determined by HadoopFileSystemOptions.hdfs_full_urls.

    Args:
      url: (str) A URL in the form hdfs://path/...

View on GitHub (pinned to 12126d8942)

Solutions

1. Add --hdfs_user=<username> to pipeline options (e.g. the hdfs superuser or your tenant user).
2. Set 'hdfs_user': 'hduser' in the options dict.
3. Confirm the user has WebHDFS permissions on the target paths to avoid later permission errors.
4. Validate the trio hdfs_host/hdfs_port/hdfs_user in a preflight check.

Example fix

// before
PipelineOptions(['--hdfs_host=namenode.example.com', '--hdfs_port=50070'])
// after
PipelineOptions(['--hdfs_host=namenode.example.com', '--hdfs_port=50070', '--hdfs_user=hduser'])

def require_hdfs_user(opts):
    v = (opts.get('hdfs_user') if isinstance(opts, dict)
         else opts.view_as(HadoopFileSystemOptions).hdfs_user)
    if not v:
        raise ValueError('Set --hdfs_user before launching')
    return v

None

try:
    fs = HadoopFileSystem(pipeline_options=opts)
except ValueError as e:
    if 'hdfs_user is not set' in str(e):
        raise SystemExit('Add --hdfs_user=<user> to pipeline options')
    raise

When it happens

Trigger: Initializing HadoopFileSystem with hdfs_host and hdfs_port configured but no 'hdfs_user' / --hdfs_user flag.

Common situations: Cluster configs where a default OS user is assumed but WebHDFS requires an explicit user; multi-tenant setups where the worker runs as a service account; options dict missing the key.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

• pipeline_options is not set
• hdfs_host is not set
• hdfs_port is not set
• Cannot create a temporary directory for root path prefix %s.
• MatchContinuously(timestamp_cursor=True) deduplicates, so it

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/ab3f77bd8eeffb72. Report an issue: GitHub.