apache/hadoop · error · RuntimeException

exception in compare

Error message

exception in compare

What it means

Error "exception in compare" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/JobSubmitter.java:379

        jobSubmitDir.getFileSystem(job), splits);
    return splits.length;
  }
  
  private static class SplitComparator implements Comparator<InputSplit> {
    @Override
    public int compare(InputSplit o1, InputSplit o2) {
      try {
        long len1 = o1.getLength();
        long len2 = o2.getLength();
        if (len1 < len2) {
          return 1;
        } else if (len1 == len2) {
          return 0;
        } else {
          return -1;
        }
      } catch (IOException ie) {
        throw new RuntimeException("exception in compare", ie);
      } catch (InterruptedException ie) {
        throw new RuntimeException("exception in compare", ie);
      }
    }
  }
  
  @SuppressWarnings("unchecked")
  private void readTokensFromFiles(Configuration conf, Credentials credentials)
  throws IOException {
    // add tokens and secrets coming from a token storage file
    String binaryTokenFilename =
      conf.get(MRJobConfig.MAPREDUCE_JOB_CREDENTIALS_BINARY);
    if (binaryTokenFilename != null) {
      Credentials binary = Credentials.readTokenStorageFile(
          FileSystem.getLocal(conf).makeQualified(
              new Path(binaryTokenFilename)),
          conf);
      credentials.addAll(binary);

View on GitHub (pinned to 2add963021)

Solutions

1. Fix the comparator/serialization used to sort input splits so comparisons do not throw; see the wrapped exception for details.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/JobSubmitter.java:379 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/de6fdd7212470df2. Report an issue: GitHub.