apache/hadoop · error · IOException

<block> found without <numBytes>

Error message

<block> found without <numBytes>

What it means

Error "<block> found without <numBytes>" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageReconstructor.java:757

  }

  private HdfsProtos.BlockProto.Builder createBlockBuilder(Node block)
      throws IOException {
    HdfsProtos.BlockProto.Builder blockBld =
        HdfsProtos.BlockProto.newBuilder();
    Long id = block.removeChildLong(SECTION_ID);
    if (id == null) {
      throw new IOException("<block> found without <id>");
    }
    blockBld.setBlockId(id);
    Long genstamp = block.removeChildLong(INODE_SECTION_GENSTAMP);
    if (genstamp == null) {
      throw new IOException("<block> found without <genstamp>");
    }
    blockBld.setGenStamp(genstamp);
    Long numBytes = block.removeChildLong(INODE_SECTION_NUM_BYTES);
    if (numBytes == null) {
      throw new IOException("<block> found without <numBytes>");
    }
    blockBld.setNumBytes(numBytes);
    return blockBld;
  }

  private void processDirectoryXml(Node node,
          INodeSection.INode.Builder inodeBld) throws IOException {
    inodeBld.setType(INodeSection.INode.Type.DIRECTORY);
    INodeSection.INodeDirectory.Builder bld =
        createINodeDirectoryBuilder(node);
    inodeBld.setDirectory(bld);
    // Will check remaining keys and serialize in processINodeXml
  }

  private INodeSection.INodeDirectory.Builder
      createINodeDirectoryBuilder(Node node) throws IOException {
    INodeSection.INodeDirectory.Builder bld =
        INodeSection.INodeDirectory.newBuilder();

View on GitHub (pinned to 2add963021)

Solutions

1. Add the missing <numBytes> element to the <block> stanza in the fsimage XML.
2. Regenerate the fsimage XML with 'hdfs oiv' from a valid fsimage.

When it happens

Trigger: Thrown by oiv -r when a <block> stanza in the fsimage XML is missing its mandatory <numBytes> element.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/a081f6f9abf625ab. Report an issue: GitHub.