在Mysql官方幫助文檔中，詳細記錄中Mysql的啓動方式，有mysqld_safe、mysql.server、mysql_multi這三種。關於mysql_multi的介紹：
Mysqld_multi可以管理多個幀聽不同Unix套接字文件和TCP/IP端口的連接的mysqld 進程。它可以啓動或停止服務器，或報告它們的當前狀態。
即可以管理多個實例。
筆者在之前也介紹過使用mysqld_safe啓用多實例的方法，啓動和關閉都指定配置文件，實例間是對立的，互不影響。成功的部署了多個實例主從Replication，今天也介紹下mysql_multi多實例管理，配置簡單，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 #根據自己的mysql目錄配置
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、初始化數據庫目錄：
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
初始話成功，會提示OK，否則查看數據庫目錄是否有權限。
3、啓動多實例：
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
注意這裏的1、2對應my.cnf配置文件 mysqld1、mysqld2，以此來區分。
4、本機登錄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、關閉數據庫實例
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