Elasticsearch的特点

1)可以作为一个大型分布式集群(数百台服务器)技术,处理PB级数据,服务大公司,也可以运行在在单击上,服务小公司
2)elasticsearch不是什么新技术,主要是将全文检索,数据分析以及分布式技术,合并一起,才形成了独一无二的ES,lucene(全文检索)
3)对用户而言,是开箱即用的,非常简单,作为中小型的应用,直接3分钟部署一下ES,就可以作为生产环境的系统来使用了,数据量不大,操作不是太复杂.
4)数据库的功能面对很多领域是不够的,优势,事务,各种联机事物型的操作,特殊的功能,比如全文检索,同义词处理,相关度排名,复杂数据分析,海量数据的近实时处理,Elasticsearch作为传统数据库的一个补充,提供了数据库所不能提供的很多功能

Elasticsearch安装部署

安装方式:

image.png

开始部署:

1.安装java环境

[root@db01 ~]# yum install -y java-1.8.0-openjdk

2.创建软件目录并拉取软件

[root@db01 ~]# mkdir /data/soft -p
https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.6.0.rpm
[root@db01 soft]# wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.6.0.rpm ##如果拉取不到的话也可以用浏览器实现下载好再上传到服务器

3.使用rpm安装elasticsearch

[root@db01 soft]# rpm -ivh elasticsearch-6.6.0.rpm 
警告：elasticsearch-6.6.0.rpm: 头V4 RSA/SHA512 Signature, 密钥 ID d88e42b4: NOKEY
准备中...                         ################################# [100%])
Creating elasticsearch group... OK
Creating elasticsearch user... OK
正在升级/安装...
   1:elasticsearch-0:6.6.0-1                                            (  ################################# [100%]
### NOT starting on installation, please execute the following statements to configure elasticsearch service to start automatically using systemd
 sudo systemctl daemon-reload
 sudo systemctl enable elasticsearch.service
### You can start elasticsearch service by executing
 sudo systemctl start elasticsearch.service
Created elasticsearch keystore in /etc/elasticsearch

4.启动elasticsearch

[root@db01 soft]# sudo systemctl daemon-reload
[root@db01 soft]# sudo systemctl enable elasticsearch.service
Created symlink from /etc/systemd/system/multi-user.target.wants/elasticsearch.service to /usr/lib/systemd/system/elasticsearch.service.
[root@db01 soft]# sudo systemctl start elasticsearch.service

5.检查服务是否启动成功

[root@db01 soft]# netstat -lntup | grep 9200 ###只要9200端口打开,代表启动成功了
tcp6       0      0 127.0.0.1:9200          :::*                    LISTEN      21699/java          
tcp6       0      0 ::1:9200                :::*                    LISTEN      21699/java    
[root@db01 soft]# curl 127.0.0.1:9200 ##也可以curl下页面查看情况
{
  "name" : "NQSWGpj",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "fPKluz4TSAi7V3I0y2PhPQ",
  "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"
}

相关配置文件

[root@db01 ~]# rpm -qc elasticsearch 
/etc/elasticsearch/elasticsearch.yml  ##ES主配置文件
/etc/elasticsearch/jvm.options        ##jvm虚拟机配置
/etc/init.d/elasticsearch             ##init的启动文件 
/etc/sysconfig/elasticsearch          ##环境变量相关参数
/usr/lib/sysctl.d/elasticsearch.conf  ##jvm相关配置
/usr/lib/systemd/system/elasticsearch.service  ##system启动文件

6.修改配置文件

[root@db01 ~]# egrep -v "^$|^#" /etc/elasticsearch/elasticsearch.yml 
##节点名称
node.name: node-1 
##数据路径
path.data: /data/elasticsearch
##日志路径
path.logs: /var/log/elasticsearch
##打开内存锁定
bootstrap.memory_lock: true
##定义访问的主机
network.host: 172.16.210.53
##定义web访问端口
http.port: 9200
[root@db01 ~]# mkdir /data/elasticsearch ##记得创建数据目录
[root@db01 ~]# chown -R elasticsearch.elasticsearch /data/elasticsearch/  ##更改属主和属组
[root@db01 ~]# vim /etc/elasticsearch/jvm.options ##修改jvm相关配置
##找到这两行设置jvm使用内存
-Xms2g
-Xmx2g 
##我系统是4G内存,jvm的推荐使用内存是主机的一半,所以我就给2G最大内存,2G最小内存,最大和最小内存一样,就能做到内存锁死
[root@db01 ~]# systemctl restart elasticsearch.service  ##重启服务

内存限制说明:

1. 不要超过32G
2. 最大最小内存设置为一样
3. 配置文件设置锁定内存
4. 至少给服务器本身空余50%的内存

查看状态

[root@db01 ~]# systemctl status  elasticsearch.service 
● elasticsearch.service - Elasticsearch
   Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since 二 2020-06-16 08:20:13 CST; 3min 13s ago
     Docs: http://www.elastic.co
  Process: 21991 ExecStart=/usr/share/elasticsearch/bin/elasticsearch -p ${PID_DIR}/elasticsearch.pid --quiet (code=exited, status=78)
 Main PID: 21991 (code=exited, status=78)

6月 16 08:18:03 db01 systemd[1]: Started Elasticsearch.
6月 16 08:18:03 db01 systemd[1]: Starting Elasticsearch...
6月 16 08:20:13 db01 systemd[1]: elasticsearch.service: main process .../a
6月 16 08:20:13 db01 systemd[1]: Unit elasticsearch.service entered f...e.
6月 16 08:20:13 db01 systemd[1]: elasticsearch.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

可以看到服务是没启动起来的.
查看日志:

root@db01 ~]# tailf /var/log/elasticsearch/elasticsearch.log 
[2020-06-16T08:20:12,375][INFO ][o.e.n.Node               ] [node-1] starting ...
[2020-06-16T08:20:12,695][INFO ][o.e.t.TransportService   ] [node-1] publish_address {172.16.210.53:9300}, bound_addresses {172.16.210.53:9300}
[2020-06-16T08:20:12,711][INFO ][o.e.b.BootstrapChecks    ] [node-1] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2020-06-16T08:20:12,860][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

可以明显的看到memory locking requested for elasticsearch process but memory is not locked 这行报错

解决报错

[root@db01 ~]# systemctl edit elasticsearch #3添加两行参数
[Service]
LimitMEMLOCK=infinity

重启服务并查看状态

[root@db01 ~]# systemctl daemon-reload 
[root@db01 ~]# systemctl restart  elasticsearch
[root@db01 ~]# systemctl status elasticsearch
● elasticsearch.service - Elasticsearch
   Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/elasticsearch.service.d
           └─override.conf
   Active: active (running) since 二 2020-06-16 08:27:51 CST; 3s ago
     Docs: http://www.elastic.co
 Main PID: 22167 (java)
   CGroup: /system.slice/elasticsearch.service
           └─22167 /bin/java -Xms2g -Xmx2g -XX:+UseConcMarkSweepGC -XX:C...

6月 16 08:27:51 db01 systemd[1]: Started Elasticsearch.
6月 16 08:27:51 db01 systemd[1]: Starting Elasticsearch...
###服务启动成功
[root@db01 ~]# netstat -lntup | grep 9200 ##检查端口
tcp6       0      0 172.16.210.53:9200      :::*                    LISTEN      22461/java        
[root@db01 ~]# curl 172.16.210.53:9200 ##最后curl一下在配置文件定义的ip和端口,能返回信息就代表配置成功了
{
  "name" : "node-1",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "7cO37iSlTZK9tFFkdXW7PA",
  "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"
}