final FieldMappingMetadata fieldMappings = gfmResponse.fieldMappings(index, field);
        if (fieldMappings == null) {
            try {
                final AcknowledgedResponse pmResponse =
                        indicesClient.preparePutMapping(index).setSource(source, XContentType.JSON).execute().actionGet();
                if (pmResponse.isAcknowledged()) {

                .setFetchSource(false).setSize(fessConfig.getPageScoreBoosterMaxFetchSizeAsInteger()).execute().actionGet(requestTimeout);
        return Arrays.stream(response.getHits().getHits()).map(SearchHit::getId).toArray(n -> new String[n]);
    };

    protected Function<Map<String, Object>, Long> requestHandler = params -> {

                    esClient.admin().cluster().prepareNodesHotThreads().setIgnoreIdleThreads(ignoreIdleThreads).setInterval(interval)
                            .setThreads(threads).setTimeout(timeout).setType(type).execute().actionGet(timeout);
            append(buf, "cluster_name", () -> response.getClusterName().value()).append(',');
            final String hotThreads = response.getNodesMap().entrySet().stream().map(e -> {

        try {
            final SearchEngineClient esClient = ComponentUtil.getSearchEngineClient();
            final NodesStatsResponse response = esClient.admin().cluster().prepareNodesStats().all().execute().actionGet(10000L);
            final XContentBuilder builder = XContentFactory.jsonBuilder();
            builder.startObject();
            response.toXContent(builder, ToXContent.EMPTY_PARAMS);
            builder.endObject();