@Override
 protected URI rewriteURI(HttpServletRequest request) {
   try {
     final Server indexer = selector.pick();
     if (indexer == null) {
       throw new ISE("Cannot find instance of indexingService");
     }
     return new URI(
         request.getScheme(),
         indexer.getHost(),
         request.getRequestURI(),
         request.getQueryString(),
         null);
   } catch (URISyntaxException e) {
     throw Throwables.propagate(e);
   }
 }