/**
   * This method processes failures by iterating through each bulk response item
   *
   * @param response, a BulkResponse
   */
  private void processBulkResponseFailure(BulkResponse response) {
    logger.warn("There was failures when executing bulk : " + response.buildFailureMessage());

    if (!logger.isDebugEnabled()) return;

    for (BulkItemResponse item : response.getItems()) {
      if (item.isFailed()) {
        logger.debug(
            "Error {} occurred on index {}, type {}, id {} for {} operation ",
            item.getFailureMessage(),
            item.getIndex(),
            item.getType(),
            item.getId(),
            item.getOpType());
      }
    }
  }