如果 elasticsearch 安装过程出现如下问题

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

1、elasticsearch 安装解决第一个问题，每个进程最大同时打开文件数太小

max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]

错误意思：每个进程最大同时打开文件数太小，可通过下面2个命令查看当前数量

查看可以打开个数：

ulimit -Hn

ulimit -Sn

解决：

　　修改/etc/security/limits.conf文件，增加如下两行配置，用户退出后重新登录生效

vim /etc/security/limits.conf

*               soft    nofile          65536
*               hard    nofile          65536

2、elasticsearch 安装解决第二个问题，最大线程个数太低

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

　　问题同上，最大线程个数太低。修改配置文件/etc/security/limits.conf（和问题1是一个文件），增加配置

vim /etc/security/limits.conf

　　可通过命令查看

ulimit -Hu
ulimit -Su

[root@data47 ~]# ulimit -Hu
16068
[root@data47 ~]# ulimit -Su
16068
[root@data47 ~]#

3、elasticsearch 安装解决第三个问题

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

　　修改/etc/sysctl.conf文件，增加配置

vm.max_map_count=262144

vi /etc/sysctl.conf
sysctl -p

　　执行命令sysctl -p生效

4、elasticsearch 安装解决第四个问题

not enough master nodes discovered during pinging

检查一下防火墙有没有关闭

 systemctl status firewalld.service #检查状态
systemctl disable firewalld.service # 禁止开机启动防火墙
systemctl stop firewalld.service  # 关闭防火墙