sentIndex.set(null);
        sentDocList.clear();
        docList.add(new HashMap<>(Map.of(//
                "_id", "001", //
                "config_id", "W01", //
                "url", "http://test.com/001"//
        )));
        docList.add(new HashMap<>(Map.of(//
                "_id", "002", //
                "thumbnail", "http://test.com/002", //
                "url", "http://test.com/002"//
        )));

                        SearchEngineUtil.scroll(index, hit -> {
                            try {
                                writer.write("{\"index\":{\"_index\":\"" + index + "\",\"_id\":\""
                                        + StringEscapeUtils.escapeJson(hit.getId()) + "\"}}\n");
                                writer.write(hit.getSourceAsString());
                                writer.write("\n");

        final Map<String, Object> firstLineInnerMap = new HashMap<>();
        firstLineInnerMap.put("_index", index);
        firstLineInnerMap.put("_type", type);
        firstLineInnerMap.put("_id", item.getId());
        firstLineMap.put("index", firstLineInnerMap);

        final Map<String, Object> secondLine = new HashMap<>();

        secondLine.put("text", item.getText());

        // reading

        try {
            zos.putNextEntry(entry);
            SearchEngineUtil.scroll(index, hit -> {
                final String data = "{\"index\":{\"_index\":\"" + index + "\",\"_id\":\"" + StringEscapeUtils.escapeJson(hit.getId())
                        + "\"}}\n" + hit.getSourceAsString() + "\n";
                try {
                    zos.write(data.getBytes(Constants.CHARSET_UTF_8));

                        SearchEngineUtil.scroll(alias, hit -> {
                            try {
                                writer.write("{\"index\":{\"_index\":\"" + hit.getIndex() + "\",\"_id\":\""
                                        + StringEscapeUtils.escapeJson(hit.getId()) + "\"}}\n");
                                writer.write(hit.getSourceAsString());
                                writer.write("\n");

        }
    }

    protected Map<String, Object> toSource(final SearchLogEvent searchLogEvent) {
        final Map<String, Object> source = toLowerHyphen(searchLogEvent.toSource());
        source.put("_id", searchLogEvent.getId());
        // source.put("version_no", searchLogEvent.getVersionNo());
        source.put("event_type", searchLogEvent.getEventType());
        return source;
    }

# field names
index.field.favorite_count=favorite_count
index.field.click_count=click_count
index.field.config_id=config_id
index.field.expires=expires
index.field.url=url
index.field.doc_id=doc_id
index.field.id=_id
index.field.version=_version
index.field.seq_no=_seq_no
index.field.primary_term=_primary_term
index.field.lang=lang
index.field.has_cache=has_cache
index.field.last_modified=last_modified

    String INDEX_FIELD_URL = "index.field.url";

    /** The key of the configuration. e.g. doc_id */
    String INDEX_FIELD_doc_id = "index.field.doc_id";

    /** The key of the configuration. e.g. _id */
    String INDEX_FIELD_ID = "index.field.id";

    /** The key of the configuration. e.g. _version */
    String INDEX_FIELD_VERSION = "index.field.version";

    /** The key of the configuration. e.g. _seq_no */

                                    }
                                    final IndexRequestBuilder requestBuilder = client.prepareIndex().setIndex(configIndex)
                                            .setId(result.get("index").get("_id")).setSource(source, XContentType.JSON);
                                    builder.add(requestBuilder);
                                }
                            }
                        } catch (final Exception e) {