MySQL的多实例有两种方式可以实现
第一种、使用多个配置文件启动不同的进程来实现多实例

    这种方式的优势逻辑简单，配置简单，缺点是管理起来不太方便。
第二种、通过官方自带的mysqld_multi使用单独的配置文件来实现多实例

    这种方式定制每个实例的配置不太方面，优点是管理起来很方便，集中管理。


第一种、使用多个配置文件启动多个不同进程的情况：

环境介绍：

mysql 版本：mariadb 10.2.4

操作系统：centos 7

mysql实例数：2个

实例占用端口分别为：3306、3307、3308


环境搭建

创建mysql用户

点击(此处)折叠或打开

  1. /usr/sbin/groupadd mysql
/usr/sbin/useradd -g mysql mysql


下载MySQL

编译安装mysql

  1. tar xzvf mysql-5.1.50.tar.gz
cd mysql-5.1.50
./configure '--prefix=/usr/local/mysql' '--with-charset=utf8' '--with-extra-charsets=complex' '--with-pthread' '--enable-thread-safe-client' '--with-ssl' '--with-client-ldflags=-all-static' '--with-mysqld-ldflags=-all-static' '--with-plugins=partition,innobase,blackhole,myisam,innodb_plugin,heap,archive' '--enable-shared' '--enable-assembler'
make
make install

官网下载源码安装MySQL

cd /server/src
wget http://mirrors.tuna.tsinghua.edu.cn/mariadb//mariadb-10.2.4/bintar-linux-x86_64/mariadb-10.2.4-linux-x86_64.tar.gz
tar zxvf mariadb-10.2.4-linux-x86_64.tar.gz
mv mariadb-10.2.4-linux-x86_64 /usr/local/mysql
echo "export PATH=/usr/local/mysql/bin:$PATH" >>/etc/profile
source /etc/profile
echo $PATH


初始化数据库

  1. /usr/local/mysql/bin/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3306 --user=mysql
/usr/local/mysql/bin/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3307 --user=mysql
/usr/local/mysql/bin/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3308 --user=mysql


创建配置文件

vim /data/dbdata_3306/my.cnf
3306库的配置文件如下：
[client]
port = 3306
socket = /data/dbdata_3306/mysql.sock
[mysqld]
datadir=/data/dbdata_3306/
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
port = 3306
socket = /data/dbdata_3306/mysql.sock
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120
[mysqldump]
quick
max_allowed_packet = 256M
[mysql]
no-auto-rehash
prompt=\\u@\\d \\R:\\m>
[myisamchk]
key_buffer_size = 512M
sort_buffer_size = 512M
read_buffer = 8M
write_buffer = 8M
[mysqlhotcopy]
interactive-timeout
[mysqld_safe]
open-files-limit = 8192
vim /data/dbdata_3307/my.cnf
3307的配置文件如下：
[client]
port = 3307
socket = /data/dbdata_3307/mysql.sock
[mysqld]
datadir=/data/dbdata_3307/
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
port = 3307
socket = /data/dbdata_3307/mysql.sock
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120
[mysqldump]
quick
max_allowed_packet = 256M
[mysql]
no-auto-rehash
prompt=\\u@\\d \\R:\\m>
[myisamchk]
key_buffer_size = 512M
sort_buffer_size = 512M
read_buffer = 8M
write_buffer = 8M
[mysqlhotcopy]
interactive-timeout
[mysqld_safe]
open-files-limit = 8192
vim /data/dbdata_3308/my.cnf
3308的配置文件如下：
[client]
port = 3308
socket = /data/dbdata_3308/mysql.sock
[mysqld]
datadir=/data/dbdata_3308/
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
port = 3308
socket = /data/dbdata_3308/mysql.sock
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120
[mysqldump]
quick
max_allowed_packet = 256M
[mysql]
no-auto-rehash
prompt=\\u@\\d \\R:\\m>
[myisamchk]
key_buffer_size = 512M
sort_buffer_size = 512M
read_buffer = 8M
write_buffer = 8M
[mysqlhotcopy]
interactive-timeout
[mysqld_safe]
open-files-limit = 8192


创建自动启动脚本

###3306的启动文件如下：
vim /data/dbdata_3306/mysqld

#!/bin/bash
mysql_port=3306
mysql_username="admin"
mysql_password="password"
function_start_mysql()
{
printf "Starting MySQL...\n"
/bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/dbdata_${mysql_port}/my.cnf 2>&1 > /dev/null &
}
function_stop_mysql()
{
printf "Stoping MySQL...\n"
/usr/local/mysql/bin/mysqladmin -u ${mysql_username} -p${mysql_password} -S /data/dbdata_${mysql_port}/mysql.sock shutdown
}
function_restart_mysql()
{
printf "Restarting MySQL...\n"
function_stop_mysql
function_start_mysql
}
function_kill_mysql()
{
kill -9 $(ps -ef | grep 'bin/mysqld_safe' | grep ${mysql_port} | awk '{printf $2}')
kill -9 $(ps -ef | grep 'libexec/mysqld' | grep ${mysql_port} | awk '{printf $2}')
}
case $1 in
start)
function_start_mysql;;
stop)
function_stop_mysql;;
kill)
function_kill_mysql;;
restart)
function_stop_mysql
function_start_mysql;;
*)
echo "Usage: /data/dbdata_${mysql_port}/mysqld {start|stop|restart|kill}";;
esac
###3307的启动文件如下：
vim /data/dbdata_3307/mysqld

#!/bin/bash
mysql_port=3307
mysql_username="admin"
mysql_password="password"
function_start_mysql()
{
printf "Starting MySQL...\n"
/bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/dbdata_${mysql_port}/my.cnf 2>&1 > /dev/null &
}
function_stop_mysql()
{
printf "Stoping MySQL...\n"
/usr/local/mysql/bin/mysqladmin -u ${mysql_username} -p${mysql_password} -S /data/dbdata_${mysql_port}/mysql.sock shutdown
}
function_restart_mysql()
{
printf "Restarting MySQL...\n"
function_stop_mysql
function_start_mysql
}
function_kill_mysql()
{
kill -9 $(ps -ef | grep 'bin/mysqld_safe' | grep ${mysql_port} | awk '{printf $2}')
kill -9 $(ps -ef | grep 'libexec/mysqld' | grep ${mysql_port} | awk '{printf $2}')
}
case $1 in
start)
function_start_mysql;;
stop)
function_stop_mysql;;
kill)
function_kill_mysql;;
restart)
function_stop_mysql
function_start_mysql;;
*)
echo "Usage: /data/dbdata_${mysql_port}/mysqld {start|stop|restart|kill}";;
esac
###3308的启动文件如下：
vim /data/dbdata_3308/mysqld

#!/bin/bash
mysql_port=3308
mysql_username="admin"
mysql_password="password"
function_start_mysql()
{
printf "Starting MySQL...\n"
/bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/dbdata_${mysql_port}/my.cnf 2>&1 > /dev/null &
}
function_stop_mysql()
{
printf "Stoping MySQL...\n"
/usr/local/mysql/bin/mysqladmin -u ${mysql_username} -p${mysql_password} -S /data/dbdata_${mysql_port}/mysql.sock shutdown
}
function_restart_mysql()
{
printf "Restarting MySQL...\n"
function_stop_mysql
function_start_mysql
}
function_kill_mysql()
{
kill -9 $(ps -ef | grep 'bin/mysqld_safe' | grep ${mysql_port} | awk '{printf $2}')
kill -9 $(ps -ef | grep 'libexec/mysqld' | grep ${mysql_port} | awk '{printf $2}')
}
case $1 in
start)
function_start_mysql;;
stop)
function_stop_mysql;;
kill)
function_kill_mysql;;
restart)
function_stop_mysql
function_start_mysql;;
*)
echo "Usage: /data/dbdata_${mysql_port}/mysqld {start|stop|restart|kill}";;
esac


###脚本启动3306、3307、3308的mysqld

  1. /data/dbdata_3306/mysqld start
/data/dbdata_3307/mysqld start
/data/dbdata_3308/mysqld start


###创建开机自启动服务器（centos7，systemctl自启动服务器管理）

###mysqld3306的开机自启动服务
ln -s /data/dbdata_3306/mysqld /etc/init.d/mysqld3306
vim /lib/systemd/system/mysqld3306.service

[Unit]
Description=mysql
After=network.target
[Service]
Type=forking
ExecStart=/etc/init.d/mysqld3306 start
ExecRestart=/etc/init.d/mysqld3306 restart
ExecStop=/etc/init.d/mysqld3306  stop
PrivateTmp=true
[Install]
WantedBy=multi-user.target
###mysqld3307的开机自启动服务
ln -s /data/dbdata_3307/mysqld /etc/init.d/mysqld3307
vim /lib/systemd/system/mysqld3307.service

[Unit]
Description=mysql
After=network.target
[Service]
Type=forking
ExecStart=/etc/init.d/mysqld3307 start
ExecRestart=/etc/init.d/mysqld3307 restart
ExecStop=/etc/init.d/mysqld3307  stop
PrivateTmp=true
[Install]
WantedBy=multi-user.target
###mysqld3308的开机自启动服务
ln -s /data/dbdata_3308/mysqld /etc/init.d/mysqld3308
vim /lib/systemd/system/mysqld3308.service

[Unit]
Description=mysql
After=network.target
[Service]
Type=forking
ExecStart=/etc/init.d/mysqld3308 start
ExecRestart=/etc/init.d/mysqld3308 restart
ExecStop=/etc/init.d/mysqld3308  stop
PrivateTmp=true
[Install]
WantedBy=multi-user.target
###测试mysqld开机自启动服务
systemct enable/start/stop/restart mysqld3306.service
systemct enable/start/stop/restart mysqld3307.service
systemct enable/start/stop/restart mysqld3308.service
CentOS 6之前系统添加到自动启动
vim /etc/init.d/boot.local
/data/dbdata_3306/mysqld start
/data/dbdata_3307/mysqld start
/data/dbdata_3308/mysqld start
如果是rhel或者centos系统的话自启动文件/etc/rc.local


### mysqladmin更改root用户密码（处于安全考虑，还需要删除系统中没有密码的帐号，这里省略了）：

  1. mysqladmin -uroot password 'xxx' -S /data/dbdata_3306/mysql.sock
mysqladmin -uroot password 'xxx' -S /data/dbdata_3307/mysql.sock
mysqladmin -uroot password 'xxx' -S /data/dbdata_3308/mysql.sock


###创建了admin帐号,mysqld控制脚本的stop功能和restart功能就正常了！

  1. mysql -uroot -pxxx -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;
  2. mysql -uroot -pxxx -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;
  3. mysql -uroot -pxxx -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;


###别名alias，优化mysql登录命令

vim /root/.bashrc
alias mysql3306='mysql -S /data/dbdata_3306/mysql.sock -uroot -pxxx'
alias mysql3307='mysql -S /data/dbdata_3307/mysql.sock -uroot -pxxx'
alias mysql3308='mysql -S /data/dbdata_3308/mysql.sock -uroot -pxxx'
###退出下次登录ssh的时候，可以直接运行mysql3306/mysql3307/mysql3308

  

 

第二种、官方自带的mysqld_multi来实现多实例实战

这里的mysql安装以及数据库的初始化和前面的步骤一样，就不再赘述。


### mysqld_multi的配置

vim /etc/my.cnf

[mysqld_multi]
mysqld = /usr/local/mysql/bin/mysqld_safe
mysqladmin = /usr/local/mysql/bin/mysqladmin
user = admin
password = password

[mysqld1]
socket = /data/dbdata_3306/mysql.sock
port = 3306
pid-file = /data/dbdata_3306/3306.pid
datadir = /data/dbdata_3306
user = mysql
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120

[mysqld2]
socket = /data/dbdata_3307/mysql.sock
port = 3307
pid-file = /data/dbdata_3307/3307.pid
datadir = /data/dbdata_3307
user = mysql
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120

[mysqld3]
socket = /data/dbdata_3308/mysql.sock
port = 3308
pid-file = /data/dbdata_3308/3308.pid
datadir = /data/dbdata_3308
user = mysql
skip-name-resolve
lower_case_table_names=1
innodb_file_per_table=1
back_log = 50
max_connections = 300
max_connect_errors = 1000
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 2M
max_heap_table_size = 64M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 64
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
default-storage-engine = innodb
thread_stack = 192K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
log-bin=mysql-bin
binlog_format=mixed
slow_query_log
long_query_time = 1
server-id = 1
key_buffer_size = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 2M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam_recover
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 200M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_file_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 60
innodb_lock_wait_timeout = 120

[mysqldump]
quick
max_allowed_packet = 256M

[mysql]
no-auto-rehash
prompt=\\u@\\d \\R:\\m>
[myisamchk]
key_buffer_size = 512M
sort_buffer_size = 512M
read_buffer = 8M
write_buffer = 8M

[mysqlhotcopy]
interactive-timeout
[mysqld_safe]
open-files-limit = 8192


### mysqld_multi启动

/usr/local/mysql/bin/mysqld_multi start 1
/usr/local/mysql/bin/mysqld_multi start 2
/usr/local/mysql/bin/mysqld_multi start 3

###或者采用一条命令的形式：
/usr/local/mysql/bin/mysqld_multi start 1-3


###更改原来密码（处于安全考虑，还需要删除系统中没有密码的帐号，这里省略了）：

/usr/local/mysql/bin/mysqladmin -uroot password 'xxx' -S /data/dbdata_3306/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'xxx' -S /data/dbdata_3307/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'xxx' -S /data/dbdata_3308/mysql.sock
 
###登录测试并创建admin密码(停止mysql的时候需要使用到)
/usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;
/usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;
/usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;


###更改环境变量

  1. vim /etc/profile
PATH=${PATH}:/usr/local/mysql/bin/
source /etc/profile


###添加到自动启动

  1. vim /etc/init.d/boot.local
/usr/local/mysql/bin/mysqld_multi start 1-3
  2. ###如果是rhel或者centos系统的话自启动文件/etc/rc.local


管理的话，在本地都是采用 -S /data/dbdata_3308/mysql.sock，如果在远程可以通过不同的端口连接上去坐管理操作。其他的和单实例的管理没什么区别！

大家在管理多实例的话可以使用mysqlmanager实例管理器，管理器来会比较方面，限于篇幅，这里就不在多做介绍！