apache/hadoop · error · IOException

<xattr> had no <ns> entry.

Error message

<xattr> had no <ns> entry.

What it means

Error "<xattr> had no <ns> entry." thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageReconstructor.java:889

      b.addEntries(v);
    }
    return b;
  }

  private INodeSection.XAttrFeatureProto.Builder xattrsXmlToProto(Node xattrs)
      throws IOException {
    INodeSection.XAttrFeatureProto.Builder bld =
        INodeSection.XAttrFeatureProto.newBuilder();
    while (true) {
      Node xattr = xattrs.removeChild(INODE_SECTION_XATTR);
      if (xattr == null) {
        break;
      }
      INodeSection.XAttrCompactProto.Builder b =
          INodeSection.XAttrCompactProto.newBuilder();
      String ns = xattr.removeChildStr(INODE_SECTION_NS);
      if (ns == null) {
        throw new IOException("<xattr> had no <ns> entry.");
      }
      int nsIdx = XAttrProtos.XAttrProto.
          XAttrNamespaceProto.valueOf(ns).ordinal();
      String name = xattr.removeChildStr(SECTION_NAME);
      String valStr = xattr.removeChildStr(INODE_SECTION_VAL);
      byte[] val = null;
      if (valStr == null) {
        String valHex = xattr.removeChildStr(INODE_SECTION_VAL_HEX);
        if (valHex == null) {
          throw new IOException("<xattr> had no <val> or <valHex> entry.");
        }
        val = new HexBinaryAdapter().unmarshal(valHex);
      } else {
        val = valStr.getBytes(StandardCharsets.UTF_8);
      }
      b.setValue(ByteString.copyFrom(val));

      // The XAttrCompactProto name field uses a fairly complex format

View on GitHub (pinned to 2add963021)

Solutions

1. Add the missing <ns> (namespace) element to the <xattr> 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 an <xattr> stanza in the fsimage XML has no <ns> (namespace) entry.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/0133d172e0edcdc2. Report an issue: GitHub.