MySQL配置问题

MySQL version：5.7

一、/etc/mysql/conf.d/ 和 /etc/mysql/mysql.conf.d/

　　在linux部署MySQL时，配置文件为/etc/mysql/my.cnf. 但其实my.cnf是长这样的：

#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

从注释（ You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options）可以得知，我们在my.cnf里头可以配置全局参数，以及用户参数。

但是直接配置在my.cnf里？-并不是

从注释（ IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored.）可以得知，my.cnf是包含了 /etc/mysql/conf.d/ 和 /etc/mysql/mysql.conf.d/ 两个目录，即只要是在此两个目录

下的后缀为.cnf文件都会被读取，所以MySQL的配置是放到了 /etc/mysql/conf.d/ 和 /etc/mysql/mysql.conf.d/.

但是如果在两个目录下都有.cnf且都配置了相同的参数，则根据顺序， /etc/mysql/mysql.conf.d/.下的配置会覆盖 /etc/mysql/conf.d/ 的配置，所以一般在一个目录下配置即可