apache/hadoop · error · IOException

Expected to find <createdListSize> in <dirDiff> section.

Error message

Expected to find <createdListSize> in <dirDiff> section.

What it means

A <dirDiff> element is missing <createdListSize>, the count of created-list entries that follow the diff header. The reconstructor needs it to set DirectoryDiff.createdListSize before scanning <created> entries, so its absence is fatal for this diff.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageReconstructor.java:1481

          throw new IOException("Expected to find <childrenSize> in " +
              "<dirDiff> section.");
        }
        bld.setIsSnapshotRoot(dirDiff.removeChildBool(
            SNAPSHOT_DIFF_SECTION_IS_SNAPSHOT_ROOT));
        bld.setChildrenSize(childrenSize);
        String name = dirDiff.removeChildStr(SECTION_NAME);
        if (name != null) {
          bld.setName(ByteString.copyFrom(name, StandardCharsets.UTF_8));
        }
        Node snapshotCopy = dirDiff.removeChild(
            SNAPSHOT_DIFF_SECTION_SNAPSHOT_COPY);
        if (snapshotCopy != null) {
          bld.setSnapshotCopy(createINodeDirectoryBuilder(snapshotCopy));
        }
        Integer expectedCreatedListSize = dirDiff.removeChildInt(
            SNAPSHOT_DIFF_SECTION_CREATED_LIST_SIZE);
        if (expectedCreatedListSize == null) {
          throw new IOException("Expected to find <createdListSize> in " +
              "<dirDiff> section.");
        }
        bld.setCreatedListSize(expectedCreatedListSize);
        while (true) {
          Node deleted = dirDiff.removeChild(
              SNAPSHOT_DIFF_SECTION_DELETED_INODE);
          if (deleted == null){
            break;
          }
          bld.addDeletedINode(Long.parseLong(deleted.getVal()));
        }
        while (true) {
          Node deleted = dirDiff.removeChild(
              SNAPSHOT_DIFF_SECTION_DELETED_INODE_REF);
          if (deleted == null){
            break;
          }
          bld.addDeletedINodeRef(Integer.parseInt(deleted.getVal()));

View on GitHub (pinned to 2add963021)

Solutions

1. Add <createdListSize>N</createdListSize> to the <dirDiff>, where N is the number of <created> children that follow
2. Verify it is a direct child of <dirDiff>, spelled exactly 'createdListSize'
3. Cross-check N against the actual <created> entries to avoid the follow-on count-mismatch error
4. Regenerate the XML with a same-version oiv when in doubt

Example fix

<!-- before -->
<dirDiff><snapshotId>3</snapshotId><childrenSize>5</childrenSize></dirDiff>
<!-- after -->
<dirDiff><snapshotId>3</snapshotId><childrenSize>5</childrenSize><createdListSize>0</createdListSize></dirDiff>

# python: every <dirDiff> needs <createdListSize>
import xml.etree.ElementTree as ET

def dirdiffs_have_createdlistsize(path):
    for ev, el in ET.iterparse(path, events=('end',)):
        if el.tag == 'dirDiff' and el.find('createdListSize') is None:
            return False
    return True

// catch oiv failure naming <createdListSize>; set it to the number of
// <created> children, remove partial output, re-run

When it happens

Trigger: A <dirDiff> where <createdListSize> was omitted, renamed, or moved inside a sibling element such as <snapshotCopy>; also diffs assembled by scripts that emit <created> entries but not the size field.

Common situations: Hand-edited diffs where created files were added/removed without touching the size field; template-based XML generation missing the field; version-skewed writers.

Related errors

• <dirDiffEntry> contained no <inodeId> entry.
• <dirDiffEntry> contained no <count> entry.
• Expected to find <childrenSize> in <dirDiff> section.
• Expected <created> entry to have a <name> field
• <fileDiffEntry> contained no <inodeid> entry.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/ea9e7d01a79de621. Report an issue: GitHub.