Elasticsearch高级聚合查询

聚合脚本处理

GET /idx_znyg_datakgzdb/_search
{
  "size": 0,
   //必须是0 否则会把整个数据输出
  "query": {
 //查询条件，先过滤数据，=SQL语法 where
    "bool": {
      "must": [
        {
          "term": {
            "bdsId": {
              "value": "nxzkjy_640303_20200706_000000031"
            }
          }
        }, {
          "range": {
            "fetchTime": {
              "gte": "2020-12-01 00:00:00",
              "lte": "2020-12-01 23:59:59"
            }
          }
        }
      ]
    }
  },
  "aggs": {
 //聚合语法，关键字 类似SQL语法中group by
    "group_by_dbid": {
  //命名随意，与aggs对应，可以理解分组数据集合的名称
      "terms": {
 //分组条件
        "field": "dbId",
  //指定分组字段
        "size": 65535
  //每个桶的数据量
      },
  //引用
      "_source": {
         "includes": [
              "bdsId",
              "nbqId",
              "fetchTime",
              "pwOutputActive"
          ],
         "excludes": []
      },
      "aggs": {
//针对桶内数据操作处理
        "db_energy": {
          "scripted_metric": {
            "init_script": {
              "lang": "painless",
              "source": """
                state.dbEnergyMap=new java.util.HashMap();

              """
            },
            "map_script": {
              "lang": "painless",
              "source": """
                String dbId = doc['dbId'].value;
                double pwPositiveTotal = doc['pwPositiveTotal'].value;
                long fetchMillis = doc['fetchTime'].value.getMillis();
                String fetchKey = '0000000000' + fetchMillis;
                fetchKey = fetchKey.substring(fetchKey.length() - 18, fetchKey.length());
                TreeMap qCombineMap = state.dbEnergyMap.get(dbId);
                if(qCombineMap == null) {
                    qCombineMap = new java.util.TreeMap();
                }
                qCombineMap.put(fetchKey, pwPositiveTotal);
                state.dbEnergyMap.put(dbId, qCombineMap);

              """
            },
            "combine_script": {
              "lang": "painless",
              "source": """
                return state;

              """
            },
            "reduce_script": {
              "lang": "painless",
              "source": """
                Map resMap = new java.util.HashMap();
                Map dbEnergyMap = new java.util.HashMap();
                for(state in states) {
                    if(state != null) {
                        for(dbId in state.dbEnergyMap.keySet()) {
                            TreeMap allQCombineMap = dbEnergyMap.get(dbId);
                            Map qCombineMap = state.dbEnergyMap.get(dbId);
                            if(allQCombineMap == null) {
                                allQCombineMap = new java.util.TreeMap();
                            }
                            allQCombineMap.putAll(qCombineMap);
                            dbEnergyMap.put(dbId, allQCombineMap);
                        }
                    }
                }
                for(dbId in dbEnergyMap.keySet()) {
                    TreeMap qCombineMap = dbEnergyMap.get(dbId);
                    double qCombine = qCombineMap.get(qCombineMap.lastKey()) - qCombineMap.get(qCombineMap.firstKey());
                    resMap.put(dbId, qCombine);
                }
                return resMap;

              """
            }
          }
        }
      }
    }
  }
}

查询参数：

shard_min_doc_count 

       shard_min_doc_count参数用于调节如果索引词实际上应该被添加到候选列表或者不应该被添加到min_doc_count中的分片所具有的确定性。如果集合中的局部碎片频率高于shard_min_doc_count计数，则仅考虑索引词。如果您的文档包含许多低频索引词，并且您对这些索引词不感兴趣（例如，拼写错误），那么您可以设置shard_min_doc_count参数以筛选分片级别上的候选索引词，即使经过合理的确定也不会达到所需的min_doc_count。合并本地计数。默认情况下，shard_min_doc_count设置为0，除非显式设置，否则不会产生任何影响。

注意
      设置shard_min_doc_count＝0也将返回与不匹配的条件的分组。然而，一些返回的文档计数为零的索引词可能只属于从其他类型删除的文档或文档，因此没有保证._all查询将找到这些索引词的正文档计数。

警告
      当不是用文档计数降序排序时，min_doc_count取值太大将使返回一些小于大小的分组，因为没有从分片收集足够的数据。丢失分组可以通过增加shard_size来恢复。设置shard_min_doc_count值太高会导致在分片级别上过滤掉索引词。这个值应该比min_doc_count/#shards低很多。

min_doc_count 

      规定了最终结果的筛选，返回最小的文档数。强制返回空数据。如果是0，时间间隔内缺少数据，则自动补充0.一般场景就是返回空数据，减少程序的处理。

Map resMap = new HashMap<>();
   String index = this.getIndex();
   SearchRequest searchRequest = new SearchRequest(index);
   SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(0);

   Date start = TimeUtil.getStatisticStartTime(currentTime, EnumTimeUnit.DAYS);
   Date end = currentTime;

   BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
   TermQueryBuilder bdsIdQueryBuilder = QueryBuilders.termQuery("bdsId", bdsId);
   RangeQueryBuilder fetchTimeQueryBuilder = QueryBuilders.rangeQuery("fetchTime").gte(start).lte(end);
   RangeQueryBuilder qOutputDailyQueryBuilder = QueryBuilders.rangeQuery("qOutputDaily").gt(0.0)
         .lte(NBQ_SERIES_DAILY_MAX_ENERGY);
   TermQueryBuilder delFlagQueryBuilder = QueryBuilders.termQuery("delFlag", DelFlagEnum.NORMAL.value());

   boolQueryBuilder.must(bdsIdQueryBuilder);
   boolQueryBuilder.must(fetchTimeQueryBuilder);
   boolQueryBuilder.must(qOutputDailyQueryBuilder);
   boolQueryBuilder.must(delFlagQueryBuilder);

   searchSourceBuilder.query(boolQueryBuilder);

   ScriptedMetricAggregationBuilder scriptedMetricAggregationBuilder = AggregationBuilders
         .scriptedMetric("nbq_energy");

   Script initScript = ScriptUtil.getScriptBy(NBQ_DAILY_SCRIPT_PATH, "init_script.js");
   Script mapScript = ScriptUtil.getScriptBy(NBQ_DAILY_SCRIPT_PATH, "map_script.js");
   Script combineScript = ScriptUtil.getScriptBy(NBQ_DAILY_SCRIPT_PATH, "combine_script.js");
   Script reduceScript = ScriptUtil.getScriptBy(NBQ_DAILY_SCRIPT_PATH, "reduce_script.js");
   scriptedMetricAggregationBuilder.initScript(initScript);
   scriptedMetricAggregationBuilder.mapScript(mapScript);
   scriptedMetricAggregationBuilder.combineScript(combineScript);
   scriptedMetricAggregationBuilder.reduceScript(reduceScript);

   //这里会生成 min_doc_count:1  shard_min_doc_count:0
   TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms("group_by_nbq").field("nbqId");
   termsAggregationBuilder.subAggregation(scriptedMetricAggregationBuilder);
   termsAggregationBuilder.size(ESPage.DEFAULT_ALL_PAGESIZE);

   searchSourceBuilder.aggregation(termsAggregationBuilder);
   //这里设置 from和size为0 意思是不放query查询出的数据，只返回分组统计数据
   searchSourceBuilder.from(0);
   searchSourceBuilder.size(0);

   searchRequest.indices(index);
   searchRequest.source(searchSourceBuilder);

   SearchResponse searchResponse = this.restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
   Aggregations aggs = searchResponse.getAggregations();
   if (aggs != null) {
      Map aggMap = aggs.getAsMap();
      ParsedMultiBucketAggregation agg = (ParsedMultiBucketAggregation) aggMap.get("group_by_nbq");
      List list = (List) agg.getBuckets();
      for (MultiBucketsAggregation.Bucket bucket : list) {
         String nbqId = bucket.getKeyAsString();
         Map nbqAggsMap = bucket.getAggregations().getAsMap();
         Aggregation aggr = nbqAggsMap.get("nbq_energy");
         if (aggr instanceof ParsedScriptedMetric) {
            ParsedScriptedMetric metric = (ParsedScriptedMetric) aggr;
            Map metaMap = (Map) metric.aggregation();
            Object data = metaMap.get(nbqId);
            if (data instanceof String) {
               if (NumberUtil.isNumber(StringUtils.trimToEmpty((String) data))) {
                  BigDecimal energy = new BigDecimal(StringUtils.trimToEmpty((String) data));
                  resMap.put(nbqId, energy);
               }
            } else if (data instanceof Double) {
               BigDecimal energy = Optional.ofNullable(BigDecimal.valueOf((Double) data))
                     .orElse(BigDecimal.valueOf(0.0));
               resMap.put(nbqId, energy);
            } else if (data instanceof BigDecimal) {
               BigDecimal energy = Optional.ofNullable((BigDecimal) data).orElse(BigDecimal.valueOf(0.0));
               resMap.put(nbqId, energy);
            }
         }
      }
   }
   return resMap;
}