mysql的多實例有兩種方式可以實現，兩種方式各有利弊。
第一種是使用多個配置文件啟動不同的進程來實現多實例，這種方式的優勢邏輯簡單，配置簡單，缺點是管理起來不太方便。
第二種是通過官方自帶的mysqld_multi使用單獨的配置文件來實現多實例，這種方式定制每個實例的配置不太方面，優點是管理起來很方便，集中管理。
下面就分別來實戰這兩種多實例的安裝和管理
環境介紹：
mysql 版本：5.1.50
操作系統：SUSE 11
mysql實例數：3個
實例占用端口分別為：3306、3307、3308
創建mysql用戶
/usr/sbin/groupadd mysql
/usr/sbin/useradd -g mysql mysql
編譯安裝mysql
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
初始化數據庫
/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
創建配置文件
vim /data/dbdata_3306/my.cnf
3306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
創建自動啟動文件
vim /data/dbdata_3306/mysqld 3306的啟動文件如下： #!/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
vim /data/dbdata_3307/mysqld
3307的啟動文件如下：
#!/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
vim /data/dbdata_3308/mysqld
3308的啟動文件如下：
#!/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
啟動3306、3307、3308的mysql
/data/dbdata_3306/mysqld start
/data/dbdata_3307/mysqld start
/data/dbdata_3308/mysqld start
更改原來密碼（處於安全考慮，還需要刪除系統中沒有密碼的帳號，這裡省略了）：
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3306/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3307/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3308/mysql.sock
登錄測試並創建關閉mysql的帳號權限，mysqld腳本要用到！
/usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3308/mysql.sock
GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password';
flush privileges;
/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;
創建了admin帳號以後腳本的stop功能和restart功能就正常了！
更改環境變量
vim /etc/profile 添加下面一行內容
PATH=${PATH}:/usr/local/mysql/bin/
source /etc/profile
添加到自動啟動
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系統的話自啟動文件/etc/rc.local
管理的話，在本地都是采用 -S /data/dbdata_3308/mysql.sock，如果在遠程可以通過不同的端口連接上去坐管理操作。其他的和單實例的管理沒什麼區別！
再來看第二種通過官方自帶的mysqld_multi來實現多實例實戰： [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啟動
/usr/local/mysql/bin/mysqld_multi start 1
/usr/local/mysql/bin/mysqld_multi start 2
/usr/local/mysql/bin/mysqld_multi start 3
或者采用一條命令的形式：
/usr/local/mysql/bin/mysqld_multi start 1-3
更改原來密碼（處於安全考慮，還需要刪除系統中沒有密碼的帳號，這裡省略了）：
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3306/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3307/mysql.sock
/usr/local/mysql/bin/mysqladmin -uroot password 'password' -S /data/dbdata_3308/mysql.sock
登錄測試並創建admin密碼(停止mysql的時候需要使用到)
/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;
更改環境變量
vim /etc/profile
PATH=${PATH}:/usr/local/mysql/bin/
source /etc/profile
添加到自動啟動
vim /etc/init.d/boot.local
/usr/local/mysql/bin/mysqld_multi start 1-3
如果是rhel或者centos系統的話自啟動文件/etc/rc.local
管理的話，在本地都是采用 -S /data/dbdata_3308/mysql.sock，如果在遠程可以通過不同的端口連接上去坐管理操作。其他的和單實例的管理沒什麼區別！
大家在管理多實例的話可以使用mysqlmanager實例管理器，管理器來會比較方面，限於篇幅，這裡就不在多做介紹！
參考資料：http://blog.chinaunix.net/uid-20639775-id-3438560.html
