elasticsearch-6.2.2安装错误解决方案
新买了个1核1G的服务器没事玩玩，安装一下elasticsearch来学学，结果刚安装就出现了各种的问题，搜索了很久找到了解决方案，记录一下，备忘
1、刚安装完成启动就出错了：error='Cannot allocate memory'
[[email protected] elasticsearch-6.2.2]# ./bin/elasticsearch -d
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c5330000, 986513408, 0) failed; error='Cannot allocate memory' (errno=12)看来是我这1G的内存太小了啊，elasticsearch使用java的jvm默认是使用1G的内存的，这里我们修改一下内存，直接把内存改到200m
[[email protected] elasticsearch-6.2.2]# vim ./config/jvm.options#修改内容
-Xms200m
-Xmx200m2、修改之后再启动试一下，结果又提示：can not run elasticsearch as root，这是不能使用root用户操作，添加一个其他的用户再试试
[[email protected] elasticsearch-6.2.2]# adduser elastic
[[email protected] elasticsearch-6.2.2]# passwd elastic
Changing password for user elastic.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
3、继续启动elasticsearch，又提示：Exception in thread "main" java.nio.file.AccessDeniedException: /usr/local/elasticsearch-6.2.2/config/jvm.options，没有jvm文件的权限，改一下所属的用户
[[email protected] elasticsearch-6.2.2]# chown elastic /usr/local/elasticsearch-6.2.2/ -R4、登录刚才新建的elastic用户，并启动elasticsearch，OK
5、尝试安装kibana，结果又出现下列错误：
[[email protected] ~]$ /usr/local/elasticsearch-6.2.2/bin/elasticsearch
。。。。。。省略其他启动信息
ERROR: [3] bootstrap checks failed
[1]: max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]
[2]: max number of threads [3895] for user [elastic] 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]
[2018-03-08T19:29:32,233][INFO ][o.e.n.Node ] [s3f1uD4] stopping ...
[2018-03-08T19:29:32,397][INFO ][o.e.n.Node ] [s3f1uD4] stopped
[2018-03-08T19:29:32,397][INFO ][o.e.n.Node ] [s3f1uD4] closing ...
[2018-03-08T19:29:32,412][INFO ][o.e.n.Node ] [s3f1uD4] closed可以看到这里出现了三个错误，提示的也很清楚了，登录到root用户，修改如下：
【1】修改/etc/security/limits.conf，修改到提示值即可
[[email protected] ~]# vim /etc/security/limits.conf
* hard nofile 65536
【2】修改/etc/security/limits.d/90-nproc.conf 文件
[[email protected] ~]# vim /etc/security/limits.conf
修改或添加
* hard nproc 4096
切换用户，如果还是不行则修改：/etc/security/limits.d/20-nproc.conf，其他文章上写的都是修改90-nproc.conf
不过我这个安装之后没有这个文件，只有一个20-nproc.conf，我的修改这个就行，刚开始学不知道什么原因
[[email protected] ~]# vim /etc/security/limits.d/20-nproc.conf
将内容改为：
* soft nproc 4096【3】修改/etc/sysctl.conf
[[email protected] ~]# vim /etc/sysctl.conf
添加配置：vm.max_map_count=262144，然后执行命令
[[email protected] ~]# sysctl -p如果是使用xshell开两个窗口的话修改完成之后一定要断开重新登录一下哦