使用mysqld_multi实现单系统中配置多个MySQL服务器实例
本文讲利用MySQL源码安装MySQL并用mysqld_multi配置多实例。 1、下载MySQL源码安装版本 到MySQL官网查找到相应版本下载，本文下载的是5.1版本 wget -c ftp://ftp.mirrorservice.org/sites/ftp.mysql.com/Downloads/MySQL-5.1/mysql-5.1.60.tar.gz 2、解压安
本文讲利用MySQL源码安装MySQL并用mysqld_multi配置多实例。
1、下载MySQL源码安装版本
到MySQL官网查找到相应版本下载，本文下载的是5.1版本
wget -c ftp://ftp.mirrorservice.org/sites/ftp.mysql.com/Downloads/MySQL-5.1/mysql-5.1.60.tar.gz
2、解压安装
tar -zxv -f mysql-5.1.60.tar.gz
./configure --prefix=/usr/local/mysql --with-charset=utf8
--with-extra-charset=all --enable-thread-safe-client --enable-assembler
--with-readline --with-big-tables
--with-named-curses-libs=/usr/lib/libncursesw.so.5
make && make install
3、添加用户和用户组
groupadd mysql #添加mysql用户组
useradd -g mysql mysql #创建mysql用户并把它放到mysql组下
chown -R root:mysql /usr/local/mysql #修改mysql文件属性
4、初始化数据目录
#把用到的工具添加到/usr/bin目录
ln -s /usr/local/mysql/bin/mysqld_multi /usr/bin/mysqld_multi
ln -s /usr/local/mysql/bin/mysql_install_db /usr/bin/mysql_install_db
#初始化四个数据目录
mysql_install_db --datadir=/usr/local/var/mysql1 --user=mysql
mysql_install_db --datadir=/usr/local/var/mysql2 --user=mysql
mysql_install_db --datadir=/usr/local/var/mysql3 --user=mysql
mysql_install_db --datadir=/usr/local/var/mysql4 --user=mysql
#修改属性
chown -R mysql /usr/local/var/mysql1
chown -R mysql /usr/local/var/mysql2
chown -R mysql /usr/local/var/mysql3
chown -R mysql /usr/local/var/mysql4
5、配置多实例启动脚本
从MySQL的源码中把复制到/etc/init.d/目录下
cp /usr/local/src/mysql-5.1.60/support-files/mysqld_multi.server /etc/init.d/mysqld_multi.server
#修改basedir和bindir为安装路径
basedir=/usr/local/mysql
bindir=/usr/local/mysql/bin
6、配置多实例数据库配置文件
用mysqld_multi工具查看该配置文件的模板方法，命令为：mysqld_multi --example
在/etc/目录下创建创建文件/etc/mysqld_multi.cnf，把mysqld_multi --example产生的文件粘进去，修改相应属性，如：mysqld,mysqladmin,socket,port,pid-file,datadir,user等。
[mysqld_multi]
mysqld = /usr/local/mysql/bin/mysqld_safe
mysqladmin = /usr/local/mysql/bin/mysqladmin
#user = mysql
#password = my_password
[mysqld1]
socket = /usr/local/var/mysql1/mysql1.sock
port = 3306
pid-file = /usr/local/var/mysql1/mysql1.pid
datadir = /usr/local/var/mysql1
#language = /usr/local/mysql/share/mysql/english
user = mysql
[mysqld2]
socket = /usr/local/var/mysql2/mysql2.sock
port = 3307
pid-file = /usr/local/var/mysql2/mysql2.pid
datadir = /usr/local/var/mysql2
#language = /usr/local/mysql/share/mysql/english
user = mysql
[mysqld3]
socket = /usr/local/var/mysql3/mysql3.sock
port = 3308
pid-file = /usr/local/var/mysql3/mysql3.pid
datadir = /usr/local/var/mysql3
#language = /usr/local/mysql/share/mysql/english
user = mysql
[mysqld4]
socket = /usr/local/var/mysql4/mysql4.sock
port = 3309
pid-file = /usr/local/var/mysql4/mysql4.pid
datadir = /usr/local/var/mysql4
#language = /usr/local/mysql/share/mysql/english
user = mysql
7、启动多实例数据库
将/usr/local/mysql/bin加到$PATH环境变量里
export PATH=/usr/local/mysql/bin:$PATH
#查看数据库状态
mysqld_multi --defaults-extra-file=/etc/mysqld_multi.cnf report
#结果都为没有运行
Reporting MySQL servers
MySQL server from group: mysqld1 is not running
MySQL server from group: mysqld2 is not running
MySQL server from group: mysqld3 is not running
MySQL server from group: mysqld4 is not running
#启动
mysqld_multi --defaults-extra-file=/etc/mysqld_multi.cnf start
#结果为
Reporting MySQL servers
MySQL server from group: mysqld1 is not running
MySQL server from group: mysqld2 is not running
MySQL server from group: mysqld3 is not running
MySQL server from group: mysqld4 is not running
#启动具体某一个实例可在start、stop后面加上具体数据1,2,3等
8、查看运行结果
#查看相应端口是否已经被监听
netstat -tunlp
#查看是否有活动进程
ps -aux|grep mysql
9、登录相应数据库
#进入端口为3306的数据库
mysql -uroot -p -h127.0.0.1 -P3306
#通过sock文件登录
mysql -uroot -p -S /usr/local/var/mysql1/mysql1.sock
#查看socket文件
mysql> SHOW VARIABLES LIKE 'socket';
#查看pid文件
mysql> SHOW VARIABLES LIKE '%pid%';