Mysql 报错 [Server] Error in accept: Too many open files

查看Mysql日志/var/log/mysqld.log，有如下报错：

2019-05-28T15:08:16.325376Z 0 [ERROR] [MY-010283] [Server] Error in accept: Too many open files

Mysql版本：

# mysql -V 
mysql Ver 8.0.15 for Linux on x86_64 (MySQL Community Server - GPL)

CentOS Linux 7 (Core)

解决方法：

查看当前Mysql数据库设置的open_files_limit值：
mysql> show variables like '%open%';

查看当前Mysql运行状态下的Open_files值：
mysql> show status like '%opene%';

1.  Change system open file limit on the fly(dynamically). 先修改服务器，修改open files限制为65535.
# ulimit -n 65535
# ulimit -Hn
65535
# ulimit -Sn
65535
# ulimit -n
65535
# ulimit -a

2. Change Mysql open file limit
vi /usr/lib/systemd/system/mysqld.service
LimitNOFILE=65535
LimitNPROC=65535

vi /usr/lib/systemd/system/mysqld.service
# Sets open_files_limit
LimitNOFILE = 65535

vi /etc/security/limits.conf
mysql hard nofile 65535
mysql soft nofile 65535

# vi /etc/systemd/system/multi-user.target.wants/mysqld.service
# Sets open_files_limit
LimitNOFILE = 65535

4.  Reload and Restart Mysqld to take effect.
systemctl daemon-reload && systemctl restart mysqld

重启后确认设置生效
mysql> show variables like '%open%';