案例实战Elasticsearch基本操作

Posted 2022-03-07 彭宇成

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问题

Elasticsearch集群的简单管理？面向文档（document）的搜索分析引擎？常用的搜索方式有哪些？

场景

本文以构建一个电商网站的后台系统为例，介绍es常用的搜索方式：query string search、query DSL、query filter、full-text search、phrase search、highlight search

注：电商网站商品管理案例背景介绍

1）对商品信息进行CRUD操作
2）执行简单的结构化查询
3）可以执行简单的全文检索，以及复杂的短语检索
4）对于全文检索的结果，可以进行高亮显示
5）对数据进行简单的聚合分析

二、商品的多种搜索方式：

分析

一、document数据格式

面向文档的搜索分析引擎

1）应用系统的数据结构都是面向对象的，复杂的
2）对象数据存储到关系型数据库中，只能拆解开来，变为扁平的多张表，每次查询的时候还得还原回对象格式，相当麻烦
3）ES是面向文档的，文档中存储的数据结构，与面向对象的数据结构是一样的，基于这种文档数据结构，ES可以提供复杂的索引、全文检索与分析聚合等功能
4）ES的document用json数据格式来表达

三、简单的集群管理

1）快速检查集群的健康状况

GET /_cat/health?v

green:每个索引的primary shard 和replica shard 都是active状态的
yellow:每个索引的primary shard都是active状态的，但是部分 replica shard 不是 active状态，处于不可用的
red:不是所有索引的 primary shard都是active状态的，部分索引有数据丢失

2）快速查看集群中有哪些索引

GET /_cat/indices?v

3）简单的索引操作

创建索引： PUT /test_index?pretty

删除索引：DELETE /test_index?pretty

四、商品的CRUD操作

1）新增商品：新增文档，建立索引

语法： PUT /index/type/id
应用：

PUT /ecommerce/product/1

"name":"gaolujie yagao",
"desc":"gaoxiao meibai",
"price":30,
"producer":"gaolujie producer",
"tags":["meibai","fangzhu"]


PUT /ecommerce/product/2

"name":"jiajieshi yagao",
"desc":"youxiao fangzhu",
"price":25,
"producer":"jiajieshi producer",
"tags":["fangzhu"]


PUT /ecommerce/product/3

"name":"zhonghua yagao",
"desc":"caoben zhiwu",
"price":40,
"producer":"zhonghua producer",
"tags":["qinxin"]

es会自动建立index和type，不需要提前创建，而且es默认会对document的每个field都建立倒排索引，让其可以被搜索。

2）查询商品：检索文档

语法：GET /index/type/id
应用：

GET /ecommerce/product/1

3) 修改商品：更新文档

语法：POST /index/type/id/_update“doc”:“fieldname”:”value”
应用：

POST /ecommerce/product/1/_update

  "doc": 
  
    "name":"jiaqiangban gaolujie yagao"

4）删除商品：删除文档

语法：DELETE /index/type/id?pretty
应用：

DELETE   /ecommerce/product/1/?pretty

五、搜索方式

1）query string search
应用）
搜索全部商品：GET /ecommerce/product/_search
搜索商品名称中包含 yagao 的商品，而且按照售价降序排序：

GET /ecommerce/product/_search?q=name:yagao&sort=price:desc

2) query DSL (domain specified language)
应用）
查询所有的商品：

GET /ecommerce/product/_search

  "query": 
  
    "match_all":

查询名称包含 yagao的商品，同时按照价格降序排序：

GET /ecommerce/product/_search

  "query": 
  
    "match":
    
      "name": "yagao"
    
  ,
  "sort": 
  [
    
      "price": 
      
        "order": "desc"
      
    
  ]

或者：

 GET /ecommerce/product/_search

  "query": 
  
    "match":
    
      "name": "yagao"
    
  ,
  "sort": 
  [
      "price": "desc"
  ]

分页查询商品，总共3条商品，假设每页就显示1条商品，显示第一页且只显示商品的名称与价格

GET ecommerce/product/_search

  "query": "match_all": ,
  "_source": ["name","price"],
  "from": 0,
  "size": 1

3) query filter

搜索商品名称包含 yagao,而且售价大于等于40的商品

GET /ecommerce/product/_search

  "query": 
  
    "bool": 
    
      "must": 
      
        "match":
        
          "name":"yagao"
        
      ,
      "filter": 
      
        "range":
        
          "price":
          
            "gte": 40

4） full-text search 全文检索

全文检索：将输入的搜索串拆解开来，去倒排索引里面去一一匹配，只要能匹配上任意一个拆解后的单词，就可以作为结果返回

GET /ecommerce/product/_search

  "query": 
  
    "match":
    
      "producer": "yagao producer"

结果：


  "took": 10,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 4,
    "max_score": 0.51623213,
    "hits": [
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "5",
        "_score": 0.51623213,
        "_source": 
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "yagao producer",
          "tags": "meibai"
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 0.25811607,
        "_source": 
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": 
          "name": "jiaqiangban gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 0.25811607,
        "_source": 
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qinxin"
          ]
        
      
    ]

5、phrase search 与高亮显示

短语搜索：要求输入的搜索串，必须在指定的字段文本中，完全包含一模一样的，才算匹配。

GET /ecommerce/product/_search

  "query": 
  
    "match_phrase":
    
      "producer": "yagao producer"
    
  ,
  "highlight": 
  
    "fields": "producer":

结果：


  "took": 45,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 1,
    "max_score": 0.51623213,
    "hits": [
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "5",
        "_score": 0.51623213,
        "_source": 
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "yagao producer",
          "tags": "meibai"
        ,
        "highlight": 
          "producer": [
            "<em>yagao</em> <em>producer</em>"
          ]
        
      
    ]

聚合分析

1）计算每个tag下的商品数量

PUT /ecommerce/_mapping/product

  "properties": 
  
    "tags":
    
      "type":"text",
      "fielddata": true
    
  


GET /ecommerce/product/_search

  "aggs":
  
    "group_by_tags":
    
      "terms":
      
        "field": "tags",
        "size": 10

结果：


  "took": 69,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 4,
    "max_score": 1,
    "hits": [
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "5",
        "_score": 1,
        "_source": 
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "yagao producer",
          "tags": "meibai"
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 1,
        "_source": 
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 1,
        "_source": 
          "name": "jiaqiangban gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 1,
        "_source": 
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qinxin"
          ]
        
      
    ]
  ,
  "aggregations": 
    "group_by_tags": 
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        
          "key": "fangzhu",
          "doc_count": 2
        ,
        
          "key": "meibai",
          "doc_count": 2
        ,
        
          "key": "qinxin",
          "doc_count": 1
        
      ]

2) 名称包含gaolujie的商品，然后按照 tags分组

GET /ecommerce/product/_search

  "size": 0,
  "query": 
  
    "match": 
    
      "name": "gaolujie"
    
  , 
  "aggs":
  
    "group_by_tags":
    
      "terms":
      
        "field": "tags"

结果：


  "took": 7,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 1,
    "max_score": 0,
    "hits": []
  ,
  "aggregations": 
    "group_by_tags": 
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        
          "key": "fangzhu",
          "doc_count": 1
        ,
        
          "key": "meibai",
          "doc_count": 1
        
      ]

3) 计算每个tag下的商品的平均价格

GET /ecommerce/product/_search

  "size": 1,
  "aggs":
  
    "group_by_tags":
    
      "terms":
      
        "field": "tags",
        "size": 10
      
      , 
      "aggs":
      
        "avg_price":
        
          "avg": 
          
            "field": "price"


  "took": 4,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 4,
    "max_score": 1,
    "hits": [
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "5",
        "_score": 1,
        "_source": 
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "yagao producer",
          "tags": "meibai"
        
      
    ]
  ,
  "aggregations": 
    "group_by_tags": 
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        
          "key": "fangzhu",
          "doc_count": 2,
          "avg_price": 
            "value": 27.5 
        ,
        
          "key": "meibai",
          "doc_count": 2,
          "avg_price": 
            "value": 40 
        ,
        
          "key": "qinxin",
          "doc_count": 1,
          "avg_price": 
            "value": 40 
        
      ]

4 ) 计算每个tag下的商品的平均价格,并且降序排序

GET /ecommerce/product/_search

  "size":0,
  "aggs":
  
    "all_tags": 
    
      "terms": 
      
        "field": "tags",
        "size": 10,
        "order":
        
          "avg_price": "desc"
        
      ,
      "aggs":
      
        "avg_price":
        
          "avg":
          
            "field": "price"

5）按照指定的价格范围区间进行分组，然后在每组内再按照tag进行分组，最后计算每组的平均价格

GET /ecommerce/product/_search

  "size": 20,
  "aggs":
  
    "group_by_price": 
    
      "range":
      
        "field": "price",
        "ranges":
        [
          
            "from": 0,
            "to": 20
          ,
          
            "from": 20,
            "to": 40
          ,
           
            "from":40,
            "to": 50
          
        ]
      ,
      "aggs":
      
        "group_by_tags":
        
          "terms":
          
            "field":"tags"
          ,
          "aggs":
          
            "average_price":
            
              "avg":
              
                "field":"price"

结果：


  "took": 5,
  "timed_out": false,
  "_shards": 
    "total": 5,
    "successful": 5,
    "failed": 0
  ,
  "hits": 
    "total": 4,
    "max_score": 1,
    "hits": [
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "5",
        "_score": 1,
        "_source": 
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "yagao producer",
          "tags": "meibai"
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 1,
        "_source": 
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 1,
        "_source": 
          "name": "jiaqiangban gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        
      ,
      
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 1,
        "_source": 
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qinxin"
          ]
        
      
    ]
  ,
  "aggregations": 
    "group_by_price": 
      "buckets": [
        
          "key": "0.0-20.0",
          "from": 0,
          "to": 20,
          "doc_count": 0,
          "group_by_tags": 
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [] 
        ,
        
          "key": "20.0-40.0",
          "from": 20,
          "to": 40,
          "doc_count": 2,
          "group_by_tags": 
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [  "key": "fangzhu", "doc_count": 2, "average_price":  "value": 27.5  ,  "key": "meibai", "doc_count": 1, "average_price":  "value": 30   ] 
        ,
        
          "key": "40.0-50.0",
          "from": 40,
          "to": 50,
          "doc_count": 1,
          "group_by_tags": 
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [  "key": "qinxin", "doc_count": 1, "average_price":  "value": 40   ] 
        
      ]

总结

参考

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