}
        try {
            final ServletContext servletContext = ComponentUtil.getComponent(ServletContext.class);
            servletContext.setSessionTrackingModes(
                    fessConfig.getSessionTrackingModesAsSet().stream().map(SessionTrackingMode::valueOf).collect(Collectors.toSet()));
        } catch (final Throwable t) {
            logger.warn("Failed to set SessionTrackingMode.", t);
        }