在Mysql官方帮助文档中，详细记录中Mysql的启动方式，有mysqld_safe、mysql.server、mysql_multi这三种。关于mysql_multi的介绍：
Mysqld_multi可以管理多个帧听不同Unix套接字文件和TCP/IP端口的连接的mysqld 进程。它可以启动或停止服务器，或报告它们的当前状态。
即可以管理多个实例。
笔者在之前也介绍过使用mysqld_safe启用多实例的方法，启动和关闭都指定配置文件，实例间是对立的，互不影响。成功的部署了多个实例主从Replication，今天也介绍下mysql_multi多实例管理，配置简单，方便管理。
1、首先配置my.cnf文件，列出我的Mysql配置文件：
[mysqld_multi] mysqld = /usr/local/mysql/bin/mysqld_safe #根据自己的mysql目录配置 mysqladmin = /usr/local/mysql/bin/mysqladmin [mysqld1] port = 3306 socket = /tmp/mysql3306.sock basedir=/usr/local/mysql datadir=/mysqldata/data3306 log-slow-queries=slow_query.txt long_query_time=2 skip-locking skip-name-resolve skip-innodb max_allowed_packet = 256M query_cache_size=256M max_connections=2000 max_connect_errors=10000 key_buffer_size=6000M read_buffer_size=32M read_rnd_buffer_size = 32M myisam_sort_buffer_size=512M tmp_table_size=1024M old-passwords interactive_timeout=60 wait_timeout=60 connect_timeout=60 table_cache=8192 thread_cache_size=512 sort_buffer_size=128M back_log = 500 thread_concurrency=48 expire_logs_days=10 log-bin=mysql-bin [mysqld2] port = 3307 socket = /tmp/mysql3307.sock basedir=/usr/local/mysql datadir=/mysqldata/data3307 log-slow-queries=slow_query.txt long_query_time=2 skip-locking skip-name-resolve skip-innodb max_allowed_packet = 256M query_cache_size=256M max_connections=2000 max_connect_errors=10000 key_buffer_size=6000M read_buffer_size=32M read_rnd_buffer_size = 32M myisam_sort_buffer_size=512M tmp_table_size=1024M old-passwords interactive_timeout=60 wait_timeout=60 connect_timeout=60 table_cache=8192 thread_cache_size=512 sort_buffer_size=128M back_log = 500 thread_concurrency=48 expire_logs_days=10 log-bin=mysql-bin [mysqldump] quick max_allowed_packet = 512M [mysql] no-auto-rehash [isamchk] key_buffer = 512M sort_buffer_size = 32M read_buffer = 2M write_buffer = 2M [myisamchk] key_buffer = 512M sort_buffer_size = 32M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout
2、初始化数据库目录：
shell>cd /usr/local/mysql/;./scripts/mysql_install_db --datadir=/mysqldata/data3307/ --user=mysql
shell>cd /usr/local/mysql/;./scripts/mysql_install_db --datadir=/mysqldata/data3306/ --user=mysql
初始话成功，会提示OK，否则查看数据库目录是否有权限。
3、启动多实例：
shell>/usr/local/mysql/bin/mysqld_multi start 1-2 或 shell>/usr/local/mysql/bin/mysqld_multi start 1 shell>/usr/local/mysql/bin/mysqld_multi start 2
注意这里的1、2对应my.cnf配置文件 mysqld1、mysqld2，以此来区分。
4、本机登录Mysql，如3307端口：
shell>mysql -S /tmp/mysql3307.sock mysql> show variables like 'datadir'; +---------------+----------------------+ | Variable_name | Value | +---------------+----------------------+ | datadir | /mysqldata/data3307/ | +---------------+----------------------+ 1 row in set (0.00 sec)
4、关闭数据库实例
shell>/usr/local/mysql/bin/mysqld_multi stop 1-2 或 shell>/usr/local/mysql/bin/mysqld_multi stop 1 shell>/usr/local/mysql/bin/mysqld_multi stop 2