apache/hadoop · error · org.apache.hadoop.hdfs.util.XMLUtils.InvalidXmlException

{e}

Error message

{e}

What it means

In delegationKeyFromXml(), the KEY element of a DELEGATION_KEY stanza is hex-decoded with Hex.decodeHex(). A DecoderException (odd number of hex digits or non-hex characters) is rethrown as InvalidXmlException carrying the original exception text. The XML input therefore contains a malformed hex-encoded delegation key.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogOp.java:5502

        Integer.toString(key.getKeyId()));
    XMLUtils.addSaxString(contentHandler, "EXPIRY_DATE",
        Long.toString(key.getExpiryDate()));
    if (key.getEncodedKey() != null) {
      XMLUtils.addSaxString(contentHandler, "KEY",
          Hex.encodeHexString(key.getEncodedKey()));
    }
    contentHandler.endElement("", "", "DELEGATION_KEY");
  }
  
  public static DelegationKey delegationKeyFromXml(Stanza st)
      throws InvalidXmlException {
    int keyId = Integer.parseInt(st.getValue("KEY_ID"));
    long expiryDate = Long.parseLong(st.getValue("EXPIRY_DATE"));
    byte key[] = null;
    try {
      key = Hex.decodeHex(st.getValue("KEY").toCharArray());
    } catch (DecoderException e) {
      throw new InvalidXmlException(e.toString());
    } catch (InvalidXmlException e) {
    }
    return new DelegationKey(keyId, expiryDate, key);
  }

  public static void permissionStatusToXml(ContentHandler contentHandler,
      PermissionStatus perm) throws SAXException {
    contentHandler.startElement(
        "", "", "PERMISSION_STATUS", new AttributesImpl());
    XMLUtils.addSaxString(contentHandler, "USERNAME", perm.getUserName());
    XMLUtils.addSaxString(contentHandler, "GROUPNAME", perm.getGroupName());
    fsPermissionToXml(contentHandler, perm.getPermission());
    contentHandler.endElement("", "", "PERMISSION_STATUS");
  }

  public static PermissionStatus permissionStatusFromXml(Stanza st)
      throws InvalidXmlException {
    Stanza status = st.getChildren("PERMISSION_STATUS").get(0);

View on GitHub (pinned to 2add963021)

Solutions

1. Check the KEY value: even length, only 0-9/a-f characters, no whitespace or 0x prefix.
2. Regenerate the XML from the binary edits file to get a pristine hex blob.
3. Re-encode the key correctly if you must edit: lowercase or uppercase hex both work, but digit count must be even.

Example fix

<!-- before: odd length + trailing whitespace -->
<KEY>0a1b2c3d4 </KEY>

<!-- after: even-length hex, no whitespace -->
<KEY>0a1b2c3d04</KEY>

String key = st.getValue("KEY");
boolean validHex = key != null && key.length() % 2 == 0
    && key.matches("[0-9a-fA-F]+");
if (!validHex) {
  throw new IllegalArgumentException("Malformed hex in DELEGATION_KEY/KEY");
}

try {
  DelegationKey k = FSEditLogOp.delegationKeyFromXml(st);
} catch (InvalidXmlException e) {
  // the message embeds DecoderException text: fix the KEY hex before retrying
}

When it happens

Trigger: OfflineEditsViewer XML-to-binary conversion where KEY contains whitespace, an odd-length string, a '0x' prefix, or characters outside 0-9a-f; keys truncated or reflowed by copy-paste or line-wrapping when the XML was edited or transferred.

Common situations: Hand-edited or script-mangled XML; hex blobs wrapped by email/chat transfer; tools emitting base64 where hex is required.

Related errors

• can't understand DelegationTokenIdentifier KIND {kind}
• Invalid value for FsAction
• expecting </EDITS>
• you must put <EDITS> at the top of the XML file! Got tag {}
• you must put <EDITS_VERSION> at the top of the XML file! Got

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/f1bc18637cd5430a. Report an issue: GitHub.