private void doRequest(final Req req) {
   try {
     SolrClient solrClient = clients.getSolrClient(req);
     solrClient.request(req.uReq);
   } catch (Exception e) {
     SolrException.log(log, e);
     Error error = new Error();
     error.e = e;
     error.req = req;
     if (e instanceof SolrException) {
       error.statusCode = ((SolrException) e).code();
     }
     errors.add(error);
   }
 }