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？
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：
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
1）快速检查集群的健康状况
GET /_cat/health?vgreen: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?v3）简单的索引操作
创建索引： PUT /test_index?pretty
删除索引：DELETE /test_index?pretty
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/13) 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/?pretty1）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:desc2) 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>" ] } } ] } }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 } } ] } } ] } } }