使用Java API从Elasticsearch获取所有记录

Question

我正在尝试使用Java API从Elasticsearch中获取所有记录。但我收到以下错误

N[[Wild Thing][localhost:9300][索引：数据/读取/搜索[Phase/DFS]]]；嵌套:QueryPhaseExecutionException[结果窗口太大，from+size必须小于或等于:[10000]但为[10101]。

我的代码如下所示

Client client;
try {
    client = TransportClient.builder().build().
            addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
    int from = 1;
    int to = 100;
    while (from <= 131881) {
        SearchResponse response = client
                .prepareSearch("demo_risk_data")
                .setSearchType(SearchType.DFS_QUERY_THEN_FETCH).setFrom(from)
                .setQuery(QueryBuilders.boolQuery().mustNot(QueryBuilders.termQuery("user_agent", "")))
                .setSize(to).setExplain(true).execute().actionGet();
        if (response.getHits().getHits().length > 0) {
            for (SearchHit searchData : response.getHits().getHits()) {
                JSONObject value = new JSONObject(searchData.getSource());
                System.out.println(value.toString());
            }
        }
    }
}

当前存在的记录总数为131881，因此我从from=1和to=100开始，然后得到100条记录，直到from<=131881。是有办法在哪里我可以检查获得记录的集合，比如说100，直到没有进一步的记录在ElasticSearch。

Answer 1

是的，您可以使用scroll API这样做，Java客户机也支持该API。

你可以这样做：

Client client;
try {
    client = TransportClient.builder().build().
            addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));

    QueryBuilder qb = QueryBuilders.boolQuery().mustNot(QueryBuilders.termQuery("user_agent", ""));
    SearchResponse scrollResp = client.prepareSearch("demo_risk_data")
        .addSort(SortParseElement.DOC_FIELD_NAME, SortOrder.ASC)
        .setScroll(new TimeValue(60000))
        .setQuery(qb)
        .setSize(100).execute().actionGet();

    //Scroll until no hits are returned
    while (true) {
        //Break condition: No hits are returned
        if (scrollResp.getHits().getHits().length == 0) {
            break;
        }

        // otherwise read results
        for (SearchHit hit : scrollResp.getHits().getHits()) {
            JSONObject value = new JSONObject(searchData.getSource());
            System.out.println(value.toString());
        }

        // prepare next query
        scrollResp = client.prepareSearchScroll(scrollResp.getScrollId()).setScroll(new TimeValue(60000)).execute().actionGet();
    }
}