apache/hadoop · error · IllegalStateException

Failed to initialize RestCsrfPreventionFilter.

Error message

Failed to initialize RestCsrfPreventionFilter.

What it means

Error "Failed to initialize RestCsrfPreventionFilter." thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/RestCsrfPreventionFilterHandler.java:178

   *
   * @param conf configuration to read
   * @return initialized filter, or null if CSRF protection not enabled
   */
  public static RestCsrfPreventionFilter initializeState(
      Configuration conf) {
    if (!conf.getBoolean(DFS_WEBHDFS_REST_CSRF_ENABLED_KEY,
        DFS_WEBHDFS_REST_CSRF_ENABLED_DEFAULT)) {
      return null;
    }
    String restCsrfClassName = RestCsrfPreventionFilter.class.getName();
    Map<String, String> restCsrfParams = RestCsrfPreventionFilter
        .getFilterParams(conf, "dfs.webhdfs.rest-csrf.");
    RestCsrfPreventionFilter filter = new RestCsrfPreventionFilter();
    try {
      filter.init(new DatanodeHttpServer
          .MapBasedFilterConfig(restCsrfClassName, restCsrfParams));
    } catch (ServletException e) {
      throw new IllegalStateException(
          "Failed to initialize RestCsrfPreventionFilter.", e);
    }
    return(filter);
  }
}

View on GitHub (pinned to 2add963021)

Solutions

1. Check the RestCsrfPreventionFilter init parameters (allowed user agents, browser-useragents regex) in the DataNode web config.
2. Review the DataNode log for the underlying exception and correct the filter configuration.

When it happens

Trigger: DataNode HTTP server startup when the RestCsrfPreventionFilter cannot be initialized from its configuration.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/064a75c0a76d3cc3. Report an issue: GitHub.