apache/hadoop · error · IOException

Skip not supported for IFileInputStream

Error message

Skip not supported for IFileInputStream

What it means

Error "Skip not supported for IFileInputStream" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/IFileInputStream.java:129

    if (curReadahead != null) {
      curReadahead.cancel();
    }
    if (currentOffset < dataLength) {
      byte[] t = new byte[Math.min((int)
            (Integer.MAX_VALUE & (dataLength - currentOffset)), 32 * 1024)];
      while (currentOffset < dataLength) {
        int n = read(t, 0, t.length);
        if (0 == n) {
          throw new EOFException("Could not validate checksum");
        }
      }
    }
    in.close();
  }
  
  @Override
  public long skip(long n) throws IOException {
   throw new IOException("Skip not supported for IFileInputStream");
  }
  
  public long getPosition() {
    return (currentOffset >= dataLength) ? dataLength : currentOffset;
  }
  
  public long getSize() {
    return checksumSize;
  }
  
  /**
   * Read bytes from the stream.
   * At EOF, checksum is validated, but the checksum
   * bytes are not passed back in the buffer. 
   */
  public int read(byte[] b, int off, int len) throws IOException {

    if (currentOffset >= dataLength) {

View on GitHub (pinned to 2add963021)

Solutions

1. Do not call skip() on IFileInputStream; read and discard bytes manually to advance the stream.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/IFileInputStream.java:129 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/035f9b1609a7372b. Report an issue: GitHub.