mysql使用mysqld_multi工具启动多实例

先给出实验环境/etc/my.cnf文件内容
修改内容为：
添加了[mysqld_multi]标签和多出来两个数据库的标签[mysqld3307]和[mysqld3308]
配置完成后启动方法，举一例：
mysqld_multi -defaults-file=/etc/my.cnf start 3307
连接方法为，举一例：
mysql -S /tmp/mysql3307.sock
关闭为：
在数据库中创建test用户
mysql> show grants for root@localhost;
+---------------------------------------------------------------------+
| Grants for root@localhost                                           |
+---------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION        |
+---------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> grant shutdown on *.* to 'test'@'localhost' identified by 'test' with grant option;
Query OK, 0 rows affected (0.00 sec)

然后使用root用户执行：
mysqld_mulit --defaults-file=/etc/my.cnf stop 3307


[root@localhost etc]# more /etc/my.cnf
# Example MySQL config file for large systems.
#
# This is for a large system with memory = 512M where the system runs mainly
# MySQL.
#
# MySQL programs look for option files in a set of
# locations which depend on the deployment platform.
# You can copy this option file to one of those
# locations. For information about these locations, see:
# http://dev.mysql.com/doc/mysql/en/option-files.html
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.


# The following options will be passed to all MySQL clients
[client]
#password       = your_password
port            = 3306
socket          = /tmp/mysql.sock


# Here follows entries for some specific programs
[mysqld_multi]
mysqld=/usr/local/mysql/bin/mysqld_safe
mysqladmin=/usr/local/mysql/bin/mysqladmin
user=test
password=test


# The MySQL server
[mysqld3306]
port            = 3306
socket          = /tmp/mysql3306.sock
pid-file        =/tmp/mysql3306.pid
skip-external-locking
key_buffer_size = 256M
max_allowed_packet = 1M
table_open_cache = 256
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 4M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
thread_concurrency = 8
basedir=/usr/local/mysql
datadir=/var/mysql/data
log-error = /usr/local/mysql/mysql_error.log
default-storage-engine=MyISAM
user = mysql


[mysqld3307]
port            = 3307
socket          = /tmp/mysql3307.sock
pid-file        =/tmp/mysql3307.pid
skip-external-locking
key_buffer_size = 256M
max_allowed_packet = 1M
table_open_cache = 256
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 4M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
thread_concurrency = 8
basedir=/usr/local/mysql
datadir=/var/mysql/data2
log-error = /usr/local/mysql/mysql_error7.log
default-storage-engine=MyISAM
user = mysql


[mysqld3308]
port            = 3308
socket          = /tmp/mysql3308.sock
pid-file        =/tmp/mysql3308.pid
skip-external-locking
key_buffer_size = 256M
max_allowed_packet = 1M
table_open_cache = 256
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 4M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
thread_concurrency = 8
basedir=/usr/local/mysql
datadir=/var/mysql/data3
log-error = /usr/local/mysql/mysql_error8.log
default-storage-engine=MyISAM
user = mysql






# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking


# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin


# binary logging format - mixed recommended
binlog_format=mixed


# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id       = 1


# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=, MASTER_PORT=,
#    MASTER_USER=, MASTER_PASSWORD= ;
#
#    where you replace , , by quoted strings and
#     by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =  
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =  
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =  
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin


# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = /var/mysql/data
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = /var/mysql/data
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 256M
#innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 64M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50


[mysqldump]
quick
max_allowed_packet = 16M


[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates


[myisamchk]
key_buffer_size = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M


[mysqlhotcopy]
interactive-timeout