1.什么是全文检索和Lucene

基于java环境,基于Lucene之上包装一层外壳 Lucene是一个java的搜索引擎库,操作非常繁琐

https://blog.csdn.net/sinat_35188997/article/details/83502920

2.Elasticsearch应用场景

1.搜索：电商，百科

2.高亮显示：githup

3.分析和数据挖掘

3.Elasticsearch特点

1.高性能，分布式

2.对运维友好，不需要会java语言，开箱即用

3.功能丰富

mysql和ES对比 库 索引 index 表 类型 type 字段 项 filter 行 文档 doc

4.Elasticsearch在电商搜索的实现

mysql: skuid name 1 狗粮100kg 2 猫粮50kg 3 猫罐头200g

ES: 聚合运算之后得到SKUID: 1 2

拿到ID之后,mysql就只需要简单地where查询即可 mysql: select xx from xxx where skuid 1

通俗的说就是es会在运算后得到一个值与mysql里面相对应，减少mysql的压力。

5.ES安装启动

1.下载软件
mkdir /data/soft
[root@db-01 /data/soft]# ll -h
total 268M
-rw-r--r-- 1 root root 109M Feb 25  2019 elasticsearch-6.6.0.rpm
-rw-r--r-- 1 root root 159M Sep  2 16:35 jdk-8u102-linux-x64.rpm

2.安装jdk
rpm -ivh jdk-8u102-linux-x64.rpm 
[root@db-01 /data/soft]# java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (build 1.8.0_212-b04)
OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode)

3.安装ES
rpm -ivh elasticsearch-6.6.0.rpm

4.检查
netstat -lntup|grep 9200
systemctl status elasticsearch.service

[root@db-01 ~]# curl 127.0.0.1:9200
{
  "name" : "Zr3WNj9",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "HR0ERydmTV2OH55subh7HQ",
  "version" : {
    "number" : "6.6.0",
    "build_flavor" : "default",
    "build_type" : "rpm",
    "build_hash" : "a9861f4",
    "build_date" : "2019-01-24T11:27:09.439740Z",
    "build_snapshot" : false,
    "lucene_version" : "7.6.0",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

6.ES配置

1.查看ES有哪些配置 
[root@db-01 ~]# rpm -qc elasticsearch
/etc/elasticsearch/elasticsearch.yml    #ES主配置文件    
/etc/elasticsearch/jvm.options          #jvm配置
/etc/init.d/elasticsearch               #init的启动文件
/etc/sysconfig/elasticsearch            #ES环境变量的相关配置
/usr/lib/sysctl.d/elasticsearch.conf    #ES环境变量的相关配置
/usr/lib/systemd/system/elasticsearch.service   #systemcd启动文件

2.自定义配置文件
[root@db-01 ~]# grep "^[a-Z]" /etc/elasticsearch/elasticsearch.yml 
node.name: node-1
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
bootstrap.memory_lock: true
network.host: 10.0.0.51,127.0.0.1
http.port: 9200

3.重启服务后发现报错
systemctl restart elasticsearch 

4.解决内存锁定失败:
查看日志发现提示内存锁定失败
tail -f /var/log/elasticsearch/elasticsearch.log 
[2019-09-06T10:12:35,988][ERROR][o.e.b.Bootstrap          ] [node-1] node validation exception
[1] bootstrap checks failed
[1]: memory locking requested for elasticsearch process but memory is not locked

解决方案:
systemctl edit elasticsearch
[Service]
LimitMEMLOCK=infinity
systemctl daemon-reload
systemctl restart elasticsearch

7.ES交互方式

三种交互方式
curl命令：
​ 最繁琐
​ 最复杂
​ 最容易出错
​ 不需要安装任何软件，只需要有curl命令

es-head插件
​ 查看数据方便
​ 操作相对容易
​ 需要node环境

kibana
​ 查看数据以及报表格式丰富
​ 操作很简单
​ 需要java环境和安装配置kibana

8.es-head插件的安装

注意:需要修改配置文件添加允许跨域参数

修改ES配置文件支持跨域 http.cors.enabled: true http.cors.allow-origin: "*"

es-head 三种方式: 1.npm安装方式

• 需要nodejs环境

• 需要连接国外源

2.docker安装

3.google浏览器插件

• 修改文件名为zip后缀

• 解压目录

• 拓展程序-开发者模式-打开已解压的目录

• 连接地址修改为ES的IP地址

4.具体操作命令

Head插件在5.0以后安装方式发生了改变，需要nodejs环境支持，或者直接使用别人封装好的docker镜像 插件官方地址 https://github.com/mobz/elasticsearch-head

使用docker部署elasticsearch-head
docker pull alivv/elasticsearch-head
docker run --name es-head -p 9100:9100 -dit elivv/elasticsearch-head

使用nodejs编译安装elasticsearch-head
yum install nodejs npm openssl screen -y
node -v
npm  -v
npm install -g cnpm --registry=https://registry.npm.taobao.org
cd /opt/
git clone git://github.com/mobz/elasticsearch-head.git
cd elasticsearch-head/
cnpm install
screen -S es-head
cnpm run start
Ctrl+A+D

9.kibana与ES交互

1.安装kibana
rpm -ivh kibana-6.6.0-x86_64.rpm

2.配置kibana
[root@db-01 /data/soft]# grep "^[a-Z]" /etc/kibana/kibana.yml 
server.port: 5601
server.host: "10.0.0.51"
elasticsearch.hosts: ["http://localhost:9200"]
kibana.index: ".kibana"

3.启动kibana
systemctl start kibana

4.操作ES

Dev Tools

10.插入数据

1.使用自定义的ID 
PUT oldzhang/info/1
{
  "name": "zhang",
  "age": "29"
}

2.使用随机ID
POST oldzhang/info/
{
  "name": "zhang",
  "age": "29",
  "pet": "xiaoqi"
}

3.和mysql对应关系建议单独列一个字段
POST oldzhang/info/
{
  "uid": "1",
  "name": "ya",
  "age": "29"
}


curl -XPUT '10.0.0.51:9200/oldzhang/info/1?pretty' -H 'Content-Type: application/json' -d'
{
  "uid": "1",
  "name": "ya",
  "age": "29"
}'

curl -XPUT '10.0.0.51:9200/oldzhang/info/2?pretty' -H 'Content-Type: application/json' -d'
{
  "uid": "1",
  "name": "zhang",
  "age": "29"
}'

#创建测试语句
POST oldzhang/info/
{
  "name": "zhang",
  "age": "29",
  "pet": "xiaoqi",
  "job": "it"
}

POST oldzhang/info/
{
  "name": "xiao1",
  "age": "30",
  "pet": "xiaoqi",
  "job": "it"
}

POST oldzhang/info/
{
  "name": "xiao2",
  "age": "26",
  "pet": "xiaoqi",
  "job": "it"
}

POST oldzhang/info/
{
  "name": "xiao4",
  "age": "35",
  "pet": "xiaoqi",
  "job": "it"
}

POST oldzhang/info/
{
  "name": "ya",
  "age": "28",
  "pet": "xiaomin",
  "job": "it"
}

POST oldzhang/info/
{
  "name": "xiaomin",
  "age": "26",
  "pet": "xiaowang",
  "job": "SM"
  
}

POST oldzhang/info/
{
  "name": "hemengfei",
  "age": "38",
  "pet": "xiaohe",
  "job": "3P"
}

POST oldzhang/info/
{
  "name": "xiaoyu",
  "age": "28",
  "pet": "bijiben",
  "job": "fly"
}

#简单查询
GET oldzhang/_search/

#条件查询
GET oldzhang/_search
{
  "query": {
    "term": {
      "name": {
        "value": "xiaomin"
      }
    }
  }
}

GET oldzhang/_search
{
  "query": {
    "term": {
      "job": {
        "value": "it"
      }
    }
  }
}

#多条件查询
GET /oldzhang/_search
{
    "query" : {
      "bool": {
        "must": [
          {"match": {"pet": "xiaoqi"}},
          {"match": {"name": "zhang"}}
        ],
        "filter": {
          "range": {
            "age": {
              "gte": 27,
              "lte": 30
            }
          }
          }
        }
      }
    }
}