apache/hadoop · error · IOException

Got NULL as delegation token

Error message

Got NULL as delegation token

What it means

Error "Got NULL as delegation token" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/KMSClientProvider.java:1043

        new DelegationTokenAuthenticatedURL(configurator);
    Token<?> token = null;
    try {
      final String doAsUser = getDoAsUser();
      token = getActualUgi().doAs(new PrivilegedExceptionAction<Token<?>>() {
        @Override
        public Token<?> run() throws Exception {
          // Not using the cached token here.. Creating a new token here
          // everytime.
          LOG.debug("Getting new token from {}, renewer:{}", url, renewer);
          return authUrl.getDelegationToken(url,
              new DelegationTokenAuthenticatedURL.Token(), renewer, doAsUser);
        }
      });
      if (token != null) {
        token.setService(dtService);
        LOG.info("New token created: ({})", token);
      } else {
        throw new IOException("Got NULL as delegation token");
      }
    } catch (InterruptedException e) {
      Thread.currentThread().interrupt();
    } catch (Exception e) {
      if (e instanceof IOException) {
        throw (IOException) e;
      } else {
        throw new IOException(e);
      }
    }
    return token;
  }

  @Override
  public long renewDelegationToken(final Token<?> dToken) throws IOException {
    try {
      final String doAsUser = getDoAsUser();
      final DelegationTokenAuthenticatedURL.Token token =

View on GitHub (pinned to 2add963021)

Solutions

1. The KMS server returned no delegation token; check KMS ACLs and the renewer configuration.

Example fix

Ensure the requesting user is allowed to get delegation tokens.

When it happens

Trigger: Raised at runtime when the documented precondition or configuration requirement for this operation is violated.

Common situations: Misconfigured or missing property, invalid user input, or calling the API before its prerequisites are met.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/c2956b9c34fcb8e9. Report an issue: GitHub.