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Elasticsearch nested sort filter 嵌套排序问题及解决

发布时间:2020-12-13 21:05:51 所属栏目:PHP教程 来源:网络整理
导读:官方解释 首先来看1下官方文档:Sorting by Nested Fields 看不懂的没关系,它其实就只有两句是有用的,就是那两段代码。 索引 PUT /my_index/blogpost/ 2 { "title" : "Investment secrets" , "body" : "What they dont tell you ..." , "tags" : [ "shares

官方解释

首先来看1下官方文档:Sorting by Nested Fields
看不懂的没关系,它其实就只有两句是有用的,就是那两段代码。

索引

PUT /my_index/blogpost/2 { "title": "Investment secrets","body": "What they dont tell you ...","tags": [ "shares","equities" ],"comments": [ { "name": "Mary Brown","comment": "Lies,lies,lies","age": 42,"stars": 1,"date": "2014⑴0⑴8" },{ "name": "John Smith","comment": "Youre making it up!","age": 28,"stars": 2,"date": "2014⑴0⑴6" } ] }

嵌套查询

GET /_search { "query": { "nested": { "path": "comments","filter": { "range": { "comments.date": { "gte": "2014⑴0-01","lt": "2014⑴1-01" } } } } },"sort": { "comments.stars": { "order": "asc","mode": "min","nested_filter": { "range": { "comments.date": { "gte": "2014⑴0-01","lt": "2014⑴1-01" } } } } } }

以上是官方代码,方便打不开网页的同学查看。下面是我遇到的问题及解决方法。

记录

这里只提供了RestfulAPI,我在使用java的进程中遇到了很多问题。有超过1半的时间都耗在这里了,特此记录1下。

问题

项目中使用java API,所以参照ResefulAPI写出来1段代码。
首先是有1段正确的restful 代码,这1段是仿照官方文档写的,运行后测试正确无误。

{ "sort": { "goods_sale_number.sale_num": { "order": "asc","nested_filter": { "term": { "warehouse_id": "22" } },"missing": "_last" } },"size": "99999","_source": [ "goods_sale_number","id" ] }

毛病的java代码,根据json转换的,运行后没法排序。

String flag = sortOrder.toString().equals("desc") ? "_last" : "_first"; FilterBuilder termFilter = FilterBuilders.termFilter("goods.goods_sale_number.warehouse_id",warehouseId); searchRequestBuilder.addSort(SortBuilders.fieldSort("goods_sale_number.sale_num") .setNestedFilter(FilterBuilders.nestedFilter("goods_sale_number",termFilter)) .setNestedPath("goods.goods_sale_number") .order(sortOrder).missing(flag));

乍1看,其实java代码和restful的代码并没有甚么区分,但是却1直不能使用。

分析及解决问题

  1. 我尝试过各种各样的写法,改变访问的路径,切换过滤的类型,能试过的方法都试过了,但是还是不可以正确排序。
  2. 由于SearchRequestBuilder类有1个方法可以直接setSource(String),固然,它只能单独使用。如果还有其它的参数,可使用searchRequestBuilder.setExtraSource(String)。所以我尝试把json的值放在这个函数里面使用,结果是正确的,正序逆序都是正确的。
  3. 猜想:多是转换的进程中出错了。(由于elasticsearch 是基于lucene的,所以我猜想是json转换java的结果可能和我写的不1样。实际在查看代码后发现实际上是把java代码转换成了json,放在了searchRequestBuilder.source里面

elasticsearch源码分析

源码

package org.elasticsearch.action.search; public class SearchRequestBuilder extends ActionRequestBuilder<SearchRequest,SearchResponse,SearchRequestBuilder,Client> { ... //这个方法就是解决问题的本源 public SearchRequest request() { if(this.sourceBuilder != null) { ((SearchRequest)this.request).source(this.sourceBuilder()); } return (SearchRequest)this.request; } ... }

分析

在此我们可以看到有1个this.sourceBuilder(),它里面的值,就是我们写的java代码,query,filter,sort 等等都会在这里转换成json,写入到searchRequestBuilder.source,而searchRequestBuilder.extraSource则是之前我写入的另外一部份json,得到这两部份值后对照1下。

//source "sort" : [ { "goods_sale_number.sale_num" : { "order" : "desc","missing" : "_last","nested_filter" : { "nested" : { "filter" : { "term" : { "goods.goods_sale_number.warehouse_id" : "22" } },"path" : "goods_sale_number" } },"nested_path" : "goods.goods_sale_number" } } ]
//extraSource "sort": { "goods_sale_number.sale_num": { "order": "asc","nested_filter": { "term": { "warehouse_id": "22" } },"missing": "_last" } }

可以看到有明显的不同,不同就在于,中间多了几个nested的嵌套。所以分析出多是由于对英文文档理解不当,sort里面的查询并不是是嵌套查询,只是1个普通的查询。由于它本身在添加排序的时候就已是嵌套了。

修改后的java代码:

String flag = sortOrder.toString().equals("desc") ? "_last" : "_first"; FilterBuilder termFilter = FilterBuilders.termFilter("warehouse_id",warehouseId); searchRequestBuilder.addSort(SortBuilders.fieldSort("goods_sale_number.sale_num") .setNestedFilter(termFilter) .order(sortOrder).missing(flag));

再次分析json:

//source "sort" : [ { "goods_sale_number.sale_num" : { "order" : "desc","nested_filter" : { "term" : { "warehouse_id" : "22" } } } } ]

这1次的值和restful API 的json1模1样了。再次履行后发现正确无误。

终究正确的代码

正确的java代码

String flag = sortOrder.toString().equals("desc") ? "_last" : "_first"; FilterBuilder termFilter = FilterBuilders.termFilter("warehouse_id",warehouseId); searchRequestBuilder.addSort(SortBuilders.fieldSort("goods_sale_number.sale_num") .setNestedFilter(termFilter) .order(sortOrder).missing(flag));

问题总结

  1. 把英文学好
  2. 遇到问题打断点
  3. 看源码
  4. 要有耐心
  5. 要仔细

其间遇到的其它问题(child query must only match non-parent docs)

1个毛病日志

[2015-10-20 18:15:25,553][DEBUG][action.search.type ] [local] [shop][4],node[uv2Ii94-R8a_Wk00s7bPew],[P],s[STARTED]: Failed to execute [org.elasticsearch.action.search.SearchRequest@1ba36675] org.elasticsearch.search.query.QueryPhaseExecutionException: [shop][4]: query[ConstantScore(cache(+_type:goods +org.elasticsearch.index.search.nested.NonNestedDocsFilter@5005b052))],from[0],size[10],sort["goods_sale_number.sale_num": org.elasticsearch.index.fielddata.fieldcomparator.LongValuesComparatorSource@31026d4e>!]: Query Failed [Failed to execute main query] at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:163) at org.elasticsearch.search.SearchService.loadOrExecuteQueryPhase(SearchService.java:289) at org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:300) at org.elasticsearch.search.action.SearchServiceTransportAction$5.call(SearchServiceTransportAction.java:231) at org.elasticsearch.search.action.SearchServiceTransportAction$5.call(SearchServiceTransportAction.java:228) at org.elasticsearch.search.action.SearchServiceTransportAction$23.run(SearchServiceTransportAction.java:559) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) Caused by: org.elasticsearch.common.util.concurrent.UncheckedExecutionException: java.lang.IllegalStateException: child query must only match non-parent docs,but parent docID=1 matched childScorer=class org.apache.lucene.search.ConstantScoreQuery$ConstantScorer at org.elasticsearch.common.cache.LocalCache$Segment.get(LocalCache.java:2203) at org.elasticsearch.common.cache.LocalCache.get(LocalCache.java:3937) at org.elasticsearch.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4739) at org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache.getAndLoadIfNotPresent(FixedBitSetFilterCache.java:136) at org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache.access$100(FixedBitSetFilterCache.java:73) at org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache$FixedBitSetFilterWrapper.getDocIdSet(FixedBitSetFilterCache.java:218) at org.elasticsearch.index.fielddata.IndexFieldData$XFieldComparatorSource$Nested.innerDocs(IndexFieldData.java:150) at org.elasticsearch.index.fielddata.fieldcomparator.LongValuesComparatorSource$1.getLongValues(LongValuesComparatorSource.java:73) at org.apache.lucene.search.FieldComparator$LongComparator.setNextReader(FieldComparator.java:716) at org.apache.lucene.search.TopFieldCollector$OneComparatorNonScoringCollector.setNextReader(TopFieldCollector.java:97) at org.elasticsearch.common.lucene.MultiCollector.setNextReader(MultiCollector.java:66) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:612) at org.elasticsearch.search.internal.ContextIndexSearcher.search(ContextIndexSearcher.java:191) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:581) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:533) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:510) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:345) at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:150) ... 8 more Caused by: java.lang.IllegalStateException: child query must only match non-parent docs,but parent docID=1 matched childScorer=class org.apache.lucene.search.ConstantScoreQuery$ConstantScorer at org.apache.lucene.search.join.ToParentBlockJoinQuery$BlockJoinScorer.nextDoc(ToParentBlockJoinQuery.java:286) at org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache$2.call(FixedBitSetFilterCache.java:148) at org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache$2.call(FixedBitSetFilterCache.java:136) at org.elasticsearch.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4742) at org.elasticsearch.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527) at org.elasticsearch.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2319) at org.elasticsearch.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2282) at org.elasticsearch.common.cache.LocalCache$Segment.get(LocalCache.java:2197) ... 25 more

毛病缘由

当前嵌套的字段不在父级下面。
也就是,有1个shop索引(index),它有goods类型(type),然后它的属性(properties)里面有1个嵌套类型字段 sale_number (nested),它有两个字段叫 sale_number和 id,此时如果你使用sale_number.sale_number去访问这个字段是访问不到的,需要使用goods.sale_number.sale_number,所以加上前面的type就能够了。但是这是在代码毛病的时候遇到的毛病的问题,仅此记录,它其实不能在实际使用中常常遇到。

(编辑:李大同)

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