apache/hadoop · error · IllegalArgumentException

Mismatched checkpoint type: ${id.getClass()}

Error message

Mismatched checkpoint type: ${id.getClass()}

What it means

Error "Mismatched checkpoint type: ${id.getClass()}" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/checkpoint/FSCheckpointService.java:105

    @Override
    public void close() throws IOException {
      isOpen=false;
      out.close();
    }

    @Override
    public boolean isOpen() {
      return isOpen;
    }

  }

  @Override
  public CheckpointReadChannel open(CheckpointID id)
      throws IOException, InterruptedException {
      if (!(id instanceof FSCheckpointID)) {
        throw new IllegalArgumentException(
            "Mismatched checkpoint type: " + id.getClass());
      }
      return new FSCheckpointReadChannel(
          fs.open(((FSCheckpointID) id).getPath()));
  }

  private static class FSCheckpointReadChannel
      implements CheckpointReadChannel {

    private boolean isOpen = true;
    private final ReadableByteChannel in;

    FSCheckpointReadChannel(FSDataInputStream in){
      this.in = Channels.newChannel(in);
    }

    @Override
    public int read(ByteBuffer bb) throws IOException {

View on GitHub (pinned to 2add963021)

Solutions

1. Use a checkpoint ID type matching the FSCheckpointService (FileSystemCheckpointID); mismatched custom ID types are rejected.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/checkpoint/FSCheckpointService.java:105 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/67f83f9c5e92fbc7. Report an issue: GitHub.