Mysql 多实例

1. 什么是多实例？

   就是一台机器上开启多个不同的服务端口，运行多个mysql服务进程，这些服务进程通过不同的socket监听不同的服务端口来提供各自的服务
   这些mysql实例共用一套mysql安装程序，使用不同（也可以相同）的my.cnf配置文，启动程序，数据库文件，在提供服务时，多实例mysql在逻辑上看来是各自独立，

优缺点：
节约服务器资源
并发高或慢查询时，整个实例消耗更多的系统资源，影响其它实例

1. 配置mysql

   2.1. 建立数据目录
   mkdir -p /usr/local/mysql/var/{3306,3007}

   2.2 修改配置文件my.cnf
   注意：port、server-id不能重复

       vim /usr/local/mysql/var/3306/my.cnf    [client]    port = 3306    socket = /usr/local/mysql/var/3306/mysql.sock    [mysqld]    datadir=/usr/local/mysql/var/3306/    port = 3306    socket =/usr/local/mysql/var/3306/mysql.sock    server-id = 1    skip-name-resolve    datadir=/data/mysql/3306/var/    relay-log=/data/mysql/3306/relay-bin    relay-log-info-file =/data/mysql/3306/relay-log.info    log-error=/data/mysql/3306/mysql.error    pid-file=/data/mysql/3306/mysql.pid

2. 初始化mysql

       /usr/local/mysql/bin/mysql_install_db --basedir=/usr/local/mysql --datadir=/usr/local/mysql/var/3306 --user=mysql

3. 启动mysql多实例

   4.1. 脚本启动方式：
   /usr/local/mysql/var/3306/mysqld start
   将下面命令的方式写成脚本，利用case做｛start|stop｝

   命令启动方式：mysqld_safe --defaults-file=/usr/local/mysql/3306/my.cnf4.2 创建mysql启动脚本        创建自动启动文件        vim /usr/local/mysql/var/3306/mysqld        3306的启动文件如下：     #!/bin/bash    mysql_port=3306    mysql_username="admin"    mysql_password="password"    start_mysql()    {        echo "Starting MySQL.../n"        /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/dbdata_${mysql_port}/my.cnf 2>&1 > /dev/null &    }    stop_mysql()    {        echo "Stoping MySQL.../n"        /usr/local/mysql/bin/mysqladmin -u ${mysql_username} -p${mysql_password} -S /data/dbdata_${mysql_port}/mysql.sock shutdown    }    restart_mysql()    {        echo "Restarting MySQL.../n"        stop_mysql        start_mysql    }    kill_mysql()    {        kill -9 $(ps -ef | grep 'bin/mysqld_safe' | grep ${mysql_port} | awk '{echo $2}')        kill -9 $(ps -ef | grep 'libexec/mysqld' | grep ${mysql_port} | awk '{echo $2}')    }    case $1 in        start)            start_mysql            ;;        stop)            stop_mysql            ;;        kill)            kill_mysql            ;;        restart)            function_stop_mysql            function_start_mysql            ;;        *)            echo "Usage: /data/dbdata_${mysql_port}/mysqld {start|stop|restart|kill}"        ;;    esac    给文件755执行权chmod 755 /usr/local/mysql/var/3306/mysqld

4. 停止mysql多实例

   root无密码mysqladmin -S /usr/local/mysql/3306/mysql.sock shutdownroot有密码/usr/local/mysql/bin/mysqladmin -uroot -p123456 -s /usr/local/mysql/var/3306/mysql.sock shutdown

6.### 登录mysql多实例

        /usr/local/mysql/bin/mysql -S /usr/local/mysql/3306/mysql.sock        mysql -uroot -p123456 -P 3306 -h 192.168.1.100

1. 修改mysql 多实例root密码

       /usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /usr/local/mysql/var/3306/mysql.sock    登录测试并创建关闭mysql的帐号权限，mysqld脚本要用到！    /usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3308/mysql.sock    GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';    flush privileges;    创建了admin帐号以后脚本的stop功能和restart功能就正常了！

2. 添加开机启动

   vi /etc/rc.local/usr/local/mysql/var/3306/mysqld start/usr/local/mysql/var/3307/mysqld start/usr/local/mysql/var/3308/mysqld start