apache/hadoop · error · IOException

Exception reading

Error message

Exception reading 

What it means

Error "Exception reading " thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/Credentials.java:269

  /**
   * Convenience method for reading a token storage file and loading its Tokens.
   * @param filename filename.
   * @param conf configuration.
   * @throws IOException raised on errors performing I/O.
   * @return Token.
   */
  public static Credentials readTokenStorageFile(File filename,
                                                 Configuration conf)
      throws IOException {
    DataInputStream in = null;
    Credentials credentials = new Credentials();
    try {
      in = new DataInputStream(new BufferedInputStream(
          Files.newInputStream(filename.toPath())));
      credentials.readTokenStorageStream(in);
      return credentials;
    } catch(IOException ioe) {
      throw new IOException("Exception reading " + filename, ioe);
    } finally {
      IOUtils.cleanupWithLogger(LOG, in);
    }
  }

  /**
   * Convenience method for reading a token from a DataInputStream.
   *
   * @param in DataInputStream.
   * @throws IOException raised on errors performing I/O.
   */
  public void readTokenStorageStream(DataInputStream in) throws IOException {
    byte[] magic = new byte[TOKEN_STORAGE_MAGIC.length];
    in.readFully(magic);
    if (!Arrays.equals(magic, TOKEN_STORAGE_MAGIC)) {
      throw new IOException("Bad header found in token storage.");
    }
    SerializedFormat format;

View on GitHub (pinned to 2add963021)

Solutions

1. Verify the credentials file named in the message exists and is readable by the process user.
2. Check the file for corruption; regenerate the token storage file if it is damaged.
3. Ensure the filesystem containing the file is healthy and not returning I/O errors.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/Credentials.java:269 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/f803e8744f574ebc. Report an issue: GitHub.