apache/hadoop · error · UnsupportedOperationException

Unknown type: {}

Error message

Unknown type: {}

What it means

Error "Unknown type: {}" thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/TreePath.java:110

    }
    return id;
  }

  public void accept(long pathId) {
    this.id = pathId;
    i.onAccept(this, id);
  }

  public INode toINode(UGIResolver ugi, BlockResolver blk,
      BlockAliasMap.Writer<FileRegion> out) throws IOException {
    if (stat.isFile()) {
      return toFile(ugi, blk, out);
    } else if (stat.isDirectory()) {
      return toDirectory(ugi);
    } else if (stat.isSymlink()) {
      throw new UnsupportedOperationException("symlinks not supported");
    } else {
      throw new UnsupportedOperationException("Unknown type: " + stat);
    }
  }

  @Override
  public boolean equals(Object other) {
    if (!(other instanceof TreePath)) {
      return false;
    }
    TreePath o = (TreePath) other;
    return getParentId() == o.getParentId()
      && getFileStatus().equals(o.getFileStatus());
  }

  @Override
  public int hashCode() {
    long pId = getParentId() * getFileStatus().hashCode();
    return (int)(pId ^ (pId >>> 32));
  }

View on GitHub (pinned to 2add963021)

Solutions

1. The fs2img tree walk encountered an inode type it cannot convert; remove or exclude unsupported inode types (e.g. symlinks) from the input tree.

When it happens

Trigger: fs2img TreePath encounters an entry type it does not know how to serialize (neither a file, directory, nor symlink), e.g. an unrecognized entry from the input path iteration.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/98c52ad7876dd1d7. Report an issue: GitHub.