Elasticsearch学习笔记

1.核心概念

• bucket: 一个数据分组（类似于sql group by以后的数据）
• metric：对bucket执行的某种聚合分析的操作，比如说求平均值，最大值，最小值。一些系列的统计方法(类似 select count(1)  MAX  MIN  AVG)

请求参数说明：

size: 0  ，//只要聚合结果，不要原始数据，不等于0会返回原始数据

aggs: 固定语法，对数据进行分组聚合操作（类似于group by操作）

terms: 根据字段的值进行分组

field: 根据指定的字段值进行分组

返回参数说明：

hits.hits: 我们指定的size是0，所以hits.hits就是空，否则会返回聚合原始数据

aggregations：聚合结果

buckets：根据聚合条件返回的结果集

key: 每个bucket对应分组条件的值

doc_count：每个bucket分组内数据量

默认排序规则：安装doc_count 降序排列

Aggregation 的语法

例如：

2.java代码关于脚本解析（Painless 编程调试）

第一种使用自定义聚合脚本

Map> resMap = new HashMap>();
 
String index = this.getIndex();
 
SearchRequest searchRequest = new SearchRequest(index);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(0);
 
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
TermQueryBuilder bdsIdQueryBuilder = QueryBuilders.termQuery("bdsId", bdsId);
 
BoolQueryBuilder lessThanStartQueryBuilder = QueryBuilders.boolQuery();
RangeQueryBuilder faultStartLessThanStart = QueryBuilders.rangeQuery("faultStartTime").lte(start);
RangeQueryBuilder faultEndLessThanStart = QueryBuilders.rangeQuery("faultEndTime").lte(start);
lessThanStartQueryBuilder.must(faultStartLessThanStart);
lessThanStartQueryBuilder.must(faultEndLessThanStart);
 
BoolQueryBuilder greatThanStartQueryBuilder = QueryBuilders.boolQuery();
RangeQueryBuilder faultStartGreatThanStart = QueryBuilders.rangeQuery("faultStartTime").gte(end);
RangeQueryBuilder faultEndGreatThanStart = QueryBuilders.rangeQuery("faultEndTime").gte(end);
greatThanStartQueryBuilder.must(faultStartGreatThanStart);
greatThanStartQueryBuilder.must(faultEndGreatThanStart);
 
boolQueryBuilder.must(bdsIdQueryBuilder);
boolQueryBuilder.mustNot(lessThanStartQueryBuilder);
boolQueryBuilder.mustNot(greatThanStartQueryBuilder);
 
searchSourceBuilder.query(boolQueryBuilder);
 
//这里开始是脚本聚合，自定义脚本聚合可以互相交互
ScriptedMetricAggregationBuilder scriptedMetricAggregationBuilder = AggregationBuilders
      .scriptedMetric("fault_duration");
 
//参数初始化
Map params = new HashMap();
params.put("now", now.getTime());
params.put("start", start.getTime());
params.put("end", end.getTime());
 
//脚本初始化
Script initScript = ScriptUtil.getScriptBy(CABLEFAULT_SCRIPT_PATH, "init_script.js");
Script mapScript = ScriptUtil.getScriptBy(CABLEFAULT_SCRIPT_PATH, "map_script.js");
Script combineScript = ScriptUtil.getScriptBy(CABLEFAULT_SCRIPT_PATH, "combine_script.js");
Script reduceScript = ScriptUtil.getScriptBy(CABLEFAULT_SCRIPT_PATH, "reduce_script.js");
scriptedMetricAggregationBuilder.params(params);
scriptedMetricAggregationBuilder.initScript(initScript);
scriptedMetricAggregationBuilder.mapScript(mapScript);
scriptedMetricAggregationBuilder.combineScript(combineScript);
scriptedMetricAggregationBuilder.reduceScript(reduceScript);
 
TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms("group_by_cableid")
      .field("cableId");
termsAggregationBuilder.subAggregation(scriptedMetricAggregationBuilder);
termsAggregationBuilder.size(ESPage.DEFAULT_ALL_PAGESIZE);
termsAggregationBuilder.minDocCount(0);
 
searchSourceBuilder.aggregation(termsAggregationBuilder);
 
ESPage.Builder builder = new ESPage.Builder(ESPage.DEFAULT_ALL_PAGESIZE).pageNo(0);
ESPage esPage = builder.build();
searchSourceBuilder.from(Long.valueOf(esPage.getFrom()).intValue());
searchSourceBuilder.size(0);
 
searchRequest.source(searchSourceBuilder);
//执行发送 ES调用查询
SearchResponse searchResponse = this.restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
Aggregations aggs = searchResponse.getAggregations();

第二种混合调用

String index = this.getIndex();
 
SearchRequest searchRequest = new SearchRequest(index);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(0);
 
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
TermQueryBuilder bdsIdQueryBuilder = QueryBuilders.termQuery("bdsId", bdsId);
RangeQueryBuilder evaluateTimeQueryBuilder = QueryBuilders.rangeQuery("evaluateTime").gte(start).lte(end);
TermQueryBuilder evaluateTypeQueryBuilder = QueryBuilders.termQuery("evaluateType",
      String.valueOf(evaluateType.getValue()));
boolQueryBuilder.must(bdsIdQueryBuilder);
boolQueryBuilder.must(evaluateTimeQueryBuilder);
boolQueryBuilder.must(evaluateTypeQueryBuilder);
 
searchSourceBuilder.query(boolQueryBuilder);
 
TopHitsAggregationBuilder topHitsAggregationBuilder = AggregationBuilders.topHits("top_record");
topHitsAggregationBuilder.sort("createDate", SortOrder.ASC);
topHitsAggregationBuilder.size(CommonConstant.ES_MAX_TOP_HITS);
 
 
Script filterScript=ScriptUtil.getScriptBy(HEALTH_PVLOSS_SCRIPT_PATH,"pv_filter_script.js");
 
TermsAggregationBuilder groupByEvaluateTimeAggregationBuilder = AggregationBuilders
      .terms("group_by_bds_id_evaluate_time");
groupByEvaluateTimeAggregationBuilder.script(filterScript);//注意一下这里，与第一种方式调用不一样
groupByEvaluateTimeAggregationBuilder.subAggregation(topHitsAggregationBuilder);
groupByEvaluateTimeAggregationBuilder.size(CommonConstant.ES_MAX_PAGE_SIZE);
groupByEvaluateTimeAggregationBuilder.minDocCount(0);
 
TermsAggregationBuilder groupByPvCodeAggregationBuilder = AggregationBuilders.terms("group_by_pvcode")
      .field("pvCode");
groupByPvCodeAggregationBuilder.subAggregation(groupByEvaluateTimeAggregationBuilder);
groupByPvCodeAggregationBuilder.size(CommonConstant.ES_MAX_PAGE_SIZE);
groupByPvCodeAggregationBuilder.minDocCount(0);
 
searchSourceBuilder.aggregation(groupByPvCodeAggregationBuilder);
ESPage.Builder builder = new ESPage.Builder(ESPage.DEFAULT_ALL_PAGESIZE).pageNo(0);
ESPage esPage = builder.build();
 
searchSourceBuilder.size(0);
 
searchRequest.indices(index);
searchRequest.source(searchSourceBuilder);
 
SearchResponse searchResponse = this.restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
Aggregations aggs = searchResponse.getAggregations();