final PingResponse pingResponse = searchEngineClient.ping();
            writeJsonResponse(pingResponse.getStatus() == 0 ? HttpServletResponse.SC_OK : HttpServletResponse.SC_SERVICE_UNAVAILABLE,
                    "\"data\":" + pingResponse.getMessage());
        } catch (final Exception e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Failed to process a ping request.", e);
            }

fore{content:"\f297"}.fa-wpexplorer:before{content:"\f2de"}.fa-wpforms:before{content:"\f298"}.fa-wpressr:before{content:"\f3e4"}.fa-wrench:before{content:"\f0ad"}.fa-x-ray:before{content:"\f497"}.fa-xbox:before{content:"\f412"}.fa-xing:before{content:"\f168"}.fa-xing-square:before{content:"\f169"}.fa-y-combinator:before{content:"\f23b"}.fa-yahoo:before{content:"\f19e"}.fa-yammer:before{content:"\f840"}.fa-yandex:before{content:"\f413"}.fa-yandex-international:before{content:"\f414"}.fa-yarn:bef...

fore{content:"\f297"}.fa-wpexplorer:before{content:"\f2de"}.fa-wpforms:before{content:"\f298"}.fa-wpressr:before{content:"\f3e4"}.fa-wrench:before{content:"\f0ad"}.fa-x-ray:before{content:"\f497"}.fa-xbox:before{content:"\f412"}.fa-xing:before{content:"\f168"}.fa-xing-square:before{content:"\f169"}.fa-y-combinator:before{content:"\f23b"}.fa-yahoo:before{content:"\f19e"}.fa-yammer:before{content:"\f840"}.fa-yandex:before{content:"\f413"}.fa-yandex-international:before{content:"\f414"}.fa-yarn:bef...

                logger.error(() -> "Failed to flush " + stream(indices).get(stream -> stream.collect(Collectors.joining(", "))), e);
            }
        });

    }

    public PingResponse ping() {
        try {
            final ClusterHealthResponse response =
                    client.admin().cluster().prepareHealth().execute().actionGet(ComponentUtil.getFessConfig().getIndexHealthTimeout());

        Set<String> value = (Set<String>) propMap.get(API_PING_SEARCH_ENGINE_FIELD_SET);
        if (value == null) {
            value = split(getApiPingSearchEngineFields(), ",")
                    .get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).collect(Collectors.toSet()));
            propMap.put(API_PING_SEARCH_ENGINE_FIELD_SET, value);
        }
        return value;
    }