apache/hadoop · error · IOException

MapOutputFile can't allocate spill/output file

Error message

MapOutputFile can't allocate spill/output file

What it means

Error "MapOutputFile can't allocate spill/output file" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/NativeCollectorOnlyHandler.java:169

      p = output.getSpillFileForWrite(spillNumber++, -1);
      
    } else if (command.equals(GET_COMBINE_HANDLER)) {
      if (null == combinerHandler) {
        return null;
      }
      final ReadWriteBuffer result = new ReadWriteBuffer(8);
      
      result.writeLong(combinerHandler.getId());
      return result;
    } else {
      throw new IOException("Illegal command: " + command.toString());
    }
    if (p != null) {
      final ReadWriteBuffer result = new ReadWriteBuffer();
      result.writeString(p.toUri().getPath());
      return result;
    } else {
      throw new IOException("MapOutputFile can't allocate spill/output file");
    }
  }
}

View on GitHub (pinned to 2add963021)

Solutions

1. Check mapreduce.cluster.local.dir / mapred.local.dir: the local disk must have free space and be writable so spill/output files can be allocated.
2. Increase available local disk space or add more healthy local directories for the task.

Example fix

<property><name>mapreduce.cluster.local.dir</name><value>/data1/local,/data2/local</value></property>

When it happens

Trigger: Thrown by NativeCollectorOnlyHandler when MapOutputFile cannot allocate a spill or output file on the local disk, typically due to exhausted mapred.local.dir space or permissions. Free space on the local dirs or fix their permissions.

Common situations: Local disks full; all mapred.local.dir entries unhealthy; permission problems on local dirs.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/9338eae14ac18720. Report an issue: GitHub.