apache/hadoop · error · EOFException

File is empty: ${jsonFile}

Error message

File is empty: ${jsonFile}

What it means

load(File) throws EOFException("File is empty: <path>") when the file exists and is regular but has length 0. Hadoop checks this up front because Jackson's error for a zero-byte stream (a MismatchedInputException) hides the simple fact that there is nothing to parse.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/JsonSerialization.java:184

  /**
   * Load from a JSON text file.
   * @param jsonFile input file
   * @return the parsed JSON
   * @throws IOException IO problems
   * @throws JsonParseException If the input is not well-formatted
   * @throws JsonMappingException failure to map from the JSON to this class
   */
  @SuppressWarnings("unchecked")
  public synchronized T load(File jsonFile)
      throws IOException, JsonParseException, JsonMappingException {
    if (!jsonFile.exists()) {
      throw new FileNotFoundException("No such file: " + jsonFile);
    }
    if (!jsonFile.isFile()) {
      throw new FileNotFoundException("Not a file: " + jsonFile);
    }
    if (jsonFile.length() == 0) {
      throw new EOFException("File is empty: " + jsonFile);
    }
    try {
      return mapper.readValue(jsonFile, classType);
    } catch (IOException e) {
      LOG.warn("Exception while parsing json file {}", jsonFile, e);
      throw e;
    }
  }

  /**
   * Save to a local file. Any existing file is overwritten unless
   * the OS blocks that.
   * @param file file
   * @param instance instance
   * @throws IOException IO exception
   */
  public void save(File file, T instance) throws
      IOException {

View on GitHub (pinned to 2add963021)

Solutions

1. Identify the writer that owns the file and regenerate it (re-run the job or restart the owning daemon).
2. If empty files are a legitimate 'no state yet' case, check length() first and return defaults.
3. Make the producer write atomically (temp file + rename) so empty files never appear at the final path.

Example fix

// before
MyType t = serializer.load(stateFile);

// after
if (stateFile.length() == 0) {
  return defaults(); // fresh install: no state written yet
}
return serializer.load(stateFile);

if (f.length() == 0) {
  return defaults(); // or quarantine the file for investigation
}
return serializer.load(f);

When it happens

Trigger: Loading a zero-length file: a writer created the file and crashed before writing, or an external process truncated it.

Common situations: State or metadata files left empty by an unclean shutdown; a file staged incompletely when a transfer was interrupted after create; placeholder files created by touch during setup.

Related errors

• No such file: ${jsonFile}
• Not a file: ${jsonFile}
• No data in ${path}
• No data
• ${resource}

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/c806b0119de80fb0. Report an issue: GitHub.