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，這種方式定製每個實例的配置不太方面，優點是管理起來很方便
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，這種方式定製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。
下麵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
實例占用埠分別為：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
初始化資料庫
/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 = 8192vim /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 = 8192vim /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}";; esacvim /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}";; esacvim /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的帳號許可權，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！ 更改環境變數
vim /etc/profile 添加下麵一行內容 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，在本地都是採用 -S /data/dbdata_3308/mysql.sock，如果在遠程可以通過不同的埠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：
這裡的mysql安裝以及資料庫的初始化和前面的步驟一樣，就不再贅述。
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
或者採用一條命令的形式：
/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;更改環境變數
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，在本地都是採用 -S /data/dbdata_3308/mysql.sock，如果在遠程可以通過不同的埠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
