logger.debug("Failed to process a search request.", e);
            }
            writeJsonResponse(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
        }
    }

    protected String detailedMessage(final Throwable t) {
        if (t == null) {
            return "Unknown";
        }
        Throwable target = t;
        if (target.getCause() == null) {