ElasticSearch 安装与使用

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_16399991/article/details/82971840

 

1.简介

Elastic （官网：https://www.elastic.co） 的底层是开源库 Lucene。但是，你没法直接用 Lucene，必须自己写代码去调用它的接口。Elastic 是 Lucene 的封装，提供了 REST API 的操作接口，开箱即用，通过简单的REST api 隐藏了lucene的复杂性，从而让全文搜索变得简单。

2.安装

下载地址：https://www.elastic.co/downloads/elasticsearch 

#我的系统信息
$uname -a
Linux iZ23iuzu9fvZ 2.6.32-696.20.1.el6.x86_64 #1 SMP Fri Jan 26 17:51:45 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
#下载并解压 
$ wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.4.1.tar.gz

$ tar -zxvf elasticsearch-6.4.2.tar.gz

#启动 Elastic 
$ ./bin/elasticsearch

注意：不能使用root账户启动；

如果这时报错"max virtual memory areas vm.maxmapcount [65530] is too low"，要运行下面的命令。

$ sudo sysctl -w vm.max_map_count=262144

如果一切正常，Elastic 就会在默认的9200端口运行。这时，打开另一个命令行窗口，请求该端口，会得到说明信息。

$ curl localhost:9200
{
  "name" : "mvQoSGm",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "4vUSt2_AQFSj5LZDVgR74g",
  "version" : {
    "number" : "6.4.2",
    "build_flavor" : "default",
    "build_type" : "tar",
    "build_hash" : "04711c2",
    "build_date" : "2018-09-26T13:34:09.098244Z",
    "build_snapshot" : false,
    "lucene_version" : "7.4.0",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

3.安装 中文分词插件IK

ik插件地址： https://github.com/medcl/elasticsearch-analysis-ik

我使用了方法1 进行下载安装；

#下载与你的es版本想对应的版本 
$ wget https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v6.4.1/elasticsearch-analysis-ik-6.4.1.zip
......
#解压
$ unzip elasticsearch-analysis-ik-6.4.1.zip 
......
#完成后重启es

通过_analyze 分析分词器 standard 和ik

#默认的standard 
$ curl -XGET -H "Content-Type: application/json"  "http://localhost:9200/_analyze?pretty=true" -d'{"text":"公安部：各地校车将享最高路权"}';
{
  "tokens" : [
    {
      "token" : "公",
      "start_offset" : 0,
      "end_offset" : 1,
      "type" : "<IDEOGRAPHIC>",
      "position" : 0
    },
    {
      "token" : "安",
      "start_offset" : 1,
      "end_offset" : 2,
      "type" : "<IDEOGRAPHIC>",
      "position" : 1
    },
    {
      "token" : "部",
      "start_offset" : 2,
      "end_offset" : 3,
      "type" : "<IDEOGRAPHIC>",
      "position" : 2
    },
    {
      "token" : "各",
      "start_offset" : 4,
      "end_offset" : 5,
      "type" : "<IDEOGRAPHIC>",
      "position" : 3
    },
    {
      "token" : "地",
      "start_offset" : 5,
      "end_offset" : 6,
      "type" : "<IDEOGRAPHIC>",
      "position" : 4
    },
    {
      "token" : "校",
      "start_offset" : 6,
      "end_offset" : 7,
      "type" : "<IDEOGRAPHIC>",
      "position" : 5
    },
    {
      "token" : "车",
      "start_offset" : 7,
      "end_offset" : 8,
      "type" : "<IDEOGRAPHIC>",
      "position" : 6
    },
    {
      "token" : "将",
      "start_offset" : 8,
      "end_offset" : 9,
      "type" : "<IDEOGRAPHIC>",
      "position" : 7
    },
    {
      "token" : "享",
      "start_offset" : 9,
      "end_offset" : 10,
      "type" : "<IDEOGRAPHIC>",
      "position" : 8
    },
    {
      "token" : "最",
      "start_offset" : 10,
      "end_offset" : 11,
      "type" : "<IDEOGRAPHIC>",
      "position" : 9
    },
    {
      "token" : "高",
      "start_offset" : 11,
      "end_offset" : 12,
      "type" : "<IDEOGRAPHIC>",
      "position" : 10
    },
    {
      "token" : "路",
      "start_offset" : 12,
      "end_offset" : 13,
      "type" : "<IDEOGRAPHIC>",
      "position" : 11
    },
    {
      "token" : "权",
      "start_offset" : 13,
      "end_offset" : 14,
      "type" : "<IDEOGRAPHIC>",
      "position" : 12
    }
  ]
}

ik_max_word 和 ik_smart 什么区别?

ik_max_word: 会将文本做最细粒度的拆分，比如会将“中华人民共和国国歌”拆分为“中华人民共和国,中华人民,中华,华人,人民共和国,人民,人,民,共和国,共和,和,国国,国歌”，会穷尽各种可能的组合；

ik_smart: 会做最粗粒度的拆分，比如会将“中华人民共和国国歌”拆分为“中华人民共和国,国歌”。

$curl -XGET -H "Content-Type: application/json"  "http://localhost:9200/_analyze?pretty=true" -d'{"text":"公安部：各地校车将享最高路权","analyzer": "ik_max_word"}';
{
  "tokens" : [
    {
      "token" : "公安部",
      "start_offset" : 0,
      "end_offset" : 3,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "公安",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "部",
      "start_offset" : 2,
      "end_offset" : 3,
      "type" : "CN_CHAR",
      "position" : 2
    },
    {
      "token" : "各地",
      "start_offset" : 4,
      "end_offset" : 6,
      "type" : "CN_WORD",
      "position" : 3
    },
    {
      "token" : "校车",
      "start_offset" : 6,
      "end_offset" : 8,
      "type" : "CN_WORD",
      "position" : 4
    },
    {
      "token" : "将",
      "start_offset" : 8,
      "end_offset" : 9,
      "type" : "CN_CHAR",
      "position" : 5
    },
    {
      "token" : "享",
      "start_offset" : 9,
      "end_offset" : 10,
      "type" : "CN_CHAR",
      "position" : 6
    },
    {
      "token" : "最高",
      "start_offset" : 10,
      "end_offset" : 12,
      "type" : "CN_WORD",
      "position" : 7
    },
    {
      "token" : "路",
      "start_offset" : 12,
      "end_offset" : 13,
      "type" : "CN_CHAR",
      "position" : 8
    },
    {
      "token" : "权",
      "start_offset" : 13,
      "end_offset" : 14,
      "type" : "CN_CHAR",
      "position" : 9
    }
  ]
}

$ curl -XGET -H "Content-Type: application/json"  "http://localhost:9200/_analyze?pretty=true" -d'{"text":"公安部：各地校车将享最高路权","analyzer": "ik_smart"}';
{
  "tokens" : [
    {
      "token" : "公安部",
      "start_offset" : 0,
      "end_offset" : 3,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "各地",
      "start_offset" : 4,
      "end_offset" : 6,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "校车",
      "start_offset" : 6,
      "end_offset" : 8,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "将",
      "start_offset" : 8,
      "end_offset" : 9,
      "type" : "CN_CHAR",
      "position" : 3
    },
    {
      "token" : "享",
      "start_offset" : 9,
      "end_offset" : 10,
      "type" : "CN_CHAR",
      "position" : 4
    },
    {
      "token" : "最高",
      "start_offset" : 10,
      "end_offset" : 12,
      "type" : "CN_WORD",
      "position" : 5
    },
    {
      "token" : "路",
      "start_offset" : 12,
      "end_offset" : 13,
      "type" : "CN_CHAR",
      "position" : 6
    },
    {
      "token" : "权",
      "start_offset" : 13,
      "end_offset" : 14,
      "type" : "CN_CHAR",
      "position" : 7
    }
  ]
}

可以看到 standard只是分成一个个的汉字，ik更加的智能。

4.创建 一个索引

参考官网文档Indices APIs ：https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-create-index.html 

官方例子：

curl -X PUT "localhost:9200/twitter" -H 'Content-Type: application/json' -d'
{
    "settings" : {
        "index" : {
            "number_of_shards" : 3, 
            "number_of_replicas" : 2 
        }
    }
}
'

-d指定了你的参数，我把这些参数放到了json文件中，
 

#createindex.json
  {
    
    "setings" : { 
        "refresh_interval":"5s", #代表创建新的索引后，不会立即生效，5s后刷新 默认1s
        "number_of_shards" : 1, #索引分片
        "number_of_replicas" : 0 #副本
    },  
    "mappings" : { 
        "product" : { 
            "dynamic":false,
            "properties" : { 
                "productid" : { 
                    "type" : "long" 
                },  
                "name":{
                    "type":"text", 
                    "index":true, 
                    "analyzer":"ik_max_word"
                },  
    
                "short_name":{
                    "type":"text", 
                    "index":true, 
                    "analyzer":"ik_max_word"
                },  
                "desc":{
                    "type":"text", 
                    "index":true, 
                    "analyzer":"ik_max_word"
                }   
            }   
        }   
    }   

}

然后 使用 -d‘@your jsonFile’指定你的json文件。下边我创建了一个索引名称为product（自己定义）的索引。

curl -H "Content-Type: application/json" -XPUT "http://localhost:9200/product?pretty=true" -d'@createindex.json'

返回：

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "index" : "product"
}

说明创建成功。
 

5.添加数据

官网文档 Document APIs：https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-index_.html；

我这里给上边创建的product索引添加一条数据

curl -X PUT "localhost:9200/product/product/1?pretty=true" -H 'Content-Type: application/json' -d'
{
    "productid" : 1,
    "name" : "测试添加索引产品名称",
    "short_name" : "测试添加索引产品短标题",
    "desc" : "测试添加索引产品描述"
}
'

运行后返回结果如下，创建成功。

6.查询

官方文档Search APIs ：https://www.elastic.co/guide/en/elasticsearch/reference/current/search.html

查询上边建立的product文档

查询了所有

curl -X GET "localhost:9200/product/_search?pretty"

匹配单个name 

curl -X POST "localhost:9200/product/_search?pretty=true" -H 'Content-Type: application/json' -d'
{
    "query" : {
        "match" : { 
            "name" : "中泰" 
        }
    }
}
'

可以看到只返回了一条数据：

匹配多个字段 

下边匹配desc 和short_name  为中华

curl -X POST "localhost:9200/product/_search?pretty=true" -H 'Content-Type: application/json' -d'
{
    "query" : {
        "multi_match" : { 
            "query":"中华",
            "fields" : ["desc","short_name"]
        }
    }
}
'

返回结果如下：

ik还支持高亮信息，详情可参考ik官网。

------------------------

参考 阮一峰老师博客 ：http://www.ruanyifeng.com/blog/2017/08/elasticsearch.html