centos7安装 ES集群 elasticsearch

这里写自定义目录标题

[编写启动脚本 elasticsearch.sh](#编写启动脚本 elasticsearch.sh)
[启动可能报错：elasticsearch 7.10启动报错 bootstrap checks failed](#启动可能报错：elasticsearch 7.10启动报错 bootstrap checks failed)
- - - 解决方法
    - 问题原因：
    - [注意退出xshell，重新登录：上面两个配置项改完后，ES启动用户(es 或root) **重新登录**就会生效；](#注意退出xshell，重新登录：上面两个配置项改完后，ES启动用户(es 或root) 重新登录就会生效；)
其他报错：

编写启动脚本 elasticsearch.sh

懒人编写一个用于启动、停止和重启Elasticsearch服务的shell脚本
脚本中设置环境变量，并使用su - es - c命令在es用户下执行操作
通过赋予脚本执行权限，用户可以方便地对Elasticsearch进行控制

#!/bin/sh

export JAVA_HOME=/opt/software/java11/jdk-11.0.11
export PATH= $JAVA_HOME/bin:$ PATH
export ES_HOME=/opt/software/elasticsearch/elasticsearch-7.6.1
export PATH= $ES_HOME/bin:$ PATH

if [ $# -lt 1 ]
then
echo "No Args Input..."
exit ;
fi

case $1 in start) su - es -c "$ ES_HOME/bin/elasticsearch -d -p pid"
echo "elasticsearch is started"
;;
stop)
pid=ps aux|grep elasticsearch | grep -v 'grep elasticsearch' | awk '{print $2}'
kill -9 $pid
echo "elasticsearch is stopped"
;;
restart)
pid=ps aux|grep elasticsearch | grep -v 'grep elasticsearch' | awk '{print $2}'
kill -9 $pid echo "elasticsearch is stopped" sleep 1 su - es -c "$ ES_HOME/bin/elasticsearch -d -p pid"
echo "elasticsearch is started"
;;
*)
echo "start|stop|restart"
;;
esac
exit 0

赋予执行权限：

chmod +x elasticsearch.sh

参数说明：

su - es -c "命令"，这个表示脚本内切换es用户一次并执行 -c 后面的命令，然后退出es普通用户到当前用户。

启动可能报错：elasticsearch 7.10启动报错 bootstrap checks failed

elasticsearch 7.14启动报错 bootstrap checks failed

现象一

ES使用root用户安装报错如下

Caused by: java.lang.RuntimeException: can not run elasticsearch as root

[root@localhost elasticsearch-7.14.2]# ./bin/elasticsearch
[2022-09-18T16:40:41,166][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [localhost.localdomain] 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:163) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116) ~[elasticsearch-cli-7.14.2.jar:7.14.2]
        at org.elasticsearch.cli.Command.main(Command.java:79) ~[elasticsearch-cli-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81) ~[elasticsearch-7.14.2.jar:7.14.2]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:399) ~[elasticsearch-7.14.2.jar:7.14.2]
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.14.2.jar:7.14.2]
        ... 6 more
uncaught exception in thread [main]
java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103)
        at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170)
        at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:399)
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159)
        at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150)
        at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75)
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116)
        at org.elasticsearch.cli.Command.main(Command.java:79)
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115)
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81)
For complete error details, refer to the log at /opt/ES/elasticsearch-7.14.2/logs/elasticsearch.log

解决方法

ES官方为了安全起见，禁止启用Root启动ES服务，因此我们需要进行普通用户的创建，才能正常启动ES服务。所以我们需要新建一个普通用户，并将ES安装目录授权给刚新建的用户。

[root@localhost ES]# useradd es

错误信息：

ERROR: [1] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
[2]: max number of threads [3795] for user [es] is too low, increase to at least [4096]
[3]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

问题原因：

es高版本对资源要求较高，linux系统默认配置不能满足它的要求，所以需要单独配置

解决方法：

[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]

修改vi /etc/security/limits.conf 文件，加入配置

bash 复制代码

* hard nofile 65535  # *可以是es启动用户
* soft nofile 65535

可以指定用户

[2]: max number of threads [3795] for user [es] is too low, increase to at least [4096]

修改vi /etc/security/limits.conf 文件，加入配置

es - nproc 4096   # es是我的启动用户

注意退出xshell，重新登录：上面两个配置项改完后，ES启动用户(es 或root) 重新登录就会生效；

[3]：max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

修改/etc/sysctl.config文件，加入下面配置

vi /etc/sysctl.conf

vm.max_map_count=262144

执行命令，立即生效

/sbin/sysctl -p
vm.max_map_count = 262144

启动成功

其他报错：

nested: BindException[地址已在使用];
Likely root cause: java.net.BindException: 地址已在使用
	at java.base/sun.nio.ch.Net.bind0(Native Method)
	at java.base/sun.nio.ch.Net.bind(Net.java:555)
	at java.base/sun.nio.ch.ServerSocketChannelImpl.netBind(ServerSocketChannelImpl.java:337)
	at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:294)
	at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:134)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:550)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1334)
	at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:506)
	at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:491)
	at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:973)
	at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:248)
	at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:356)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at java.base/java.lang.Thread.run(Thread.java:833)
For complete error details, refer to the log at /data/db/elastic/node-1/logs/ltkj-search.log

报错解释：

这个错误表明应用程序尝试绑定到本地计算机上的19700端口失败，因为该端口已经被其他应用程序占用。

解决方法：

查找并停止占用端口的进程：

在Windows上，可以使用命令netstat -ano | findstr :19700来查找占用端口的进程ID，然后通过任务管理器或taskkill /PID <进程ID> /F命令结束该进程。
在Linux或Mac上，可以使用lsof -i :19700或netstat -tulnp | grep :19700来查找占用端口的进程，并使用kill命令结束它。

更改应用程序配置：

如果可能，更改应用程序自身配置，使其使用不同的端口。

端口冲突处理：

如果应用程序可以配置端口，可以设置为自动选择未被使用的端口。

确保在进行任何更改之前，了解正在运行的服务及其端口的用途，以免影响系统的正常运行。