单实例安装elastic和启动报错解决

下载

先到官网https://www.elastic.co/cn/downloads/past-releases/elasticsearch-5-5-2下载，我安装的是5.5.2的版本，其余版本直接访问官网elastic.co下载须要的版本。注意：5.2.2版本使用的jdk是1.8，其余elastic版本要适当调整jdk版本，怎么安装jdk参照以前的随笔

进入官网页面以后

复制连接地址以后到linux中建立elastic目录，在elastic目录中使用命令 wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.2.tar.gz 下载

安装

解压 tar -zxvf elasticsearch-5.5.2.tar.gz 

启动

解压以后进入bin目录，直接使用命令sh elasticsearch启动便可

此时若是用的是root用户会报以下错误，由于elastic search不能用root用户启动，解决办法有不少种，我用的是建立用户的方法

[root@localhost bin]# ./elasticsearch
[2017-12-20T17:01:47,922][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [node-1] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.1.1.jar:6.1.1]
    at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:85) ~[elasticsearch-6.1.1.jar:6.1.1]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
    at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:104) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:171) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:322) ~[elasticsearch-6.1.1.jar:6.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) ~[elasticsearch-6.1.1.jar:6.1.1]
    ... 6 more

解决办法：

#建立用户

adduser elastic  

#修改密码（输入要修改的密码，第二次输入是肯定密码）

passwd elastic

#elastic文件夹权限赋给elastic用户

chown -R elastic elastic

#切换用户启动

su elastic

sh elasticsearch

看到以下信息说明启动完成，浏览器访问页面便可，默认监听9200端口