ES安装教程详解

0. 安装前准备

	centos7 +
	java 8  +
	elastic 6.2.4+

2. 在官方网站下载ES

wget http://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.4.1.tar.gz

3. 安装JDK(必须JDK1.8+)

rpm -ivh jdk-8u181-linux-x64.rpm
	/*注意:默认安装位置 /usr/java/jdk1.8.0_171-amd64*/

4. 配置环境变量

vim /etc/profile
在文件末尾加入:
	export JAVA_HOME=/usr/java/jdk1.8.0_171-amd64
	export PATH=$PATH:$JAVA_HOME/bin

5. 重载系统配置

	source /etc/profile

6. 安装elasticsearche

	tar -zxvf elasticsearch-6.4.1.tar.gz

7. elasticsearche的目录结构

    bin                         可执行的二进制文件的目录
    config                    	配置文件的目录
    lib                         运行时依赖的库
    logs  modules       		运行时日志文件
    plugins                   	es中提供的插件

8. 运行es服务

	在bin目录中执行   ./elasticsearch
	
	注意:root用户启动[2018-09-19T14:50:04,029][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root

9. 不能以root用户身份启动

a.在linux系统中创建新的组
	groupadd es

b.创建新的用户es并将es用户放入es组中
	 

c.修改es用户密码
	passwd es

d.将root用户解压的文件移动到es用户目录中
	mv /root/elasticsearch-6.2.4  /home/es/

f.改变文件的所有者
	chown -R es:es 当前es的安装目录(这里是:/home/es/elasticsearch)

10. 登录es用户启动ES

	./elasticsearch   启动ES

11. 测试ES是否启动成功

在命令终端中执行: curl http://localhost:9200 出现以下信息:
	{
      "name" : "xQK1cwT",
      "cluster_name" : "elasticsearch",
      "cluster_uuid" : "t7IYk7LKQ0mXcyyrdFWpLg",
      "version" : {
        "number" : "6.2.4",
        "build_hash" : "ccec39f",
        "build_date" : "2018-04-12T20:37:28.497551Z",
        "build_snapshot" : false,
        "lucene_version" : "7.2.1",
        "minimum_wire_compatibility_version" : "5.6.0",
        "minimum_index_compatibility_version" : "5.0.0"
      },
      "tagline" : "You Know, for Search"
    }

12. 开启ES远程访问

	vim elasticsearch.yml 将原来network修改为以下配置:
	network.host: 0.0.0.0

13. 启动时错误解决方案

a.重新启动es出现如下错误
  **ERROR: bootstrap checks failed[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]**
  解决方案:
   # 切换到root用户修改
    vim /etc/security/limits.conf
   # 在最后面追加下面内容
    *               soft    nofile          65536
    *               hard    nofile          65536
    *               soft    nproc           4096
    *               hard    nproc           4096
   # 退出重新登录检测配置是否生效:
    ulimit -Hn
    ulimit -Sn
    ulimit -Hu
    ulimit -Su

b.重新启动出现如下错误
  **ERROR: max number of threads [3802] for user [chenyn] is too low,increase to at least [4096]**
   解决方案:
   #进入limits.d目录下修改配置文件。
    vim /etc/security/limits.d/20-nproc.conf 
   # 修改为 启动ES用户名 soft nproc 4096
   
c.重新启动出现如下错误
  **ERROR: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]**
   解决方案:
    vim /etc/sysctl.conf
    vm.max_map_count=655360
   #执行以下命令生效：
    sysctl -p

14. 关闭网络防火墙

	systemctl stop firewalld
	systemctl disable firewalld

15. 外部浏览器访问即可

http://es的主机名:9200 出现如下信息说明安装成功:
{
    "name" : "xQK1cwT",
    "cluster_name" : "elasticsearch",
    "cluster_uuid" : "t7IYk7LKQ0mXcyyrdFWpLg",
    "version" : {
    "number" : "6.2.4",
    "build_hash" : "ccec39f",
    "build_date" : "2018-04-12T20:37:28.497551Z",
    "build_snapshot" : false,
    "lucene_version" : "7.2.1",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
    },
    "tagline" : "You Know, for Search"
}