apache/hadoop · error · UnsupportedOperationException

Remove Not Implemented

Error message

Remove Not Implemented

What it means

Error "Remove Not Implemented" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MarkableIterator.java:77

  @Override
  public void clearMark() throws IOException {
    baseIterator.clearMark();
  }

  @Override
  public boolean hasNext() { 
    return baseIterator.hasNext();
  }

  @Override
  public VALUE next() {
    return baseIterator.next();
  }

  @Override
  public void remove() {
    throw new UnsupportedOperationException("Remove Not Implemented");
  }
}

View on GitHub (pinned to 2add963021)

Solutions

1. Do not call remove() on MarkableIterator; it is unsupported by design.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MarkableIterator.java:77 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/bbe020eada0dc7bb. Report an issue: GitHub.