再来看第二种通过官方自带的mysqld_multi实现多实例实战：
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。下面就分别来实战这两种多实例的安装和管理

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环境介绍：
mysql 版本：5.5.29
操作系统：Centos 5.5
mysql实例数：3个
实例占用端口分别为：3306、3307、3308

这里的mysql安装以及数据库的初始化和前面的步骤一样。

必要软件包

yum -y install ncurses-devel gcc gcc-c++ gcc-g77 autoconf automake zlib* fiex* libxml* libmcrypt* libtool-ltdl-devel* libtool make cmake

创建mysql用户

/usr/sbin/groupadd mysql /usr/sbin/useradd -g mysql mysql -s /sbin/nologin

编译安装MySQL

tar -zxvf mysql-5.5.29.tar.gz && cd mysql-5.5.29 #默认情况下是安装在/usr/local/mysql cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \ -DMYSQL_DATADIR=/usr/local/mysql/data \ -DSYSCONFDIR=/etc \ -DWITH_MYISAM_STORAGE_ENGINE=1 \ -DWITH_INNOBASE_STORAGE_ENGINE=1 \ -DWITH_MEMORY_STORAGE_ENGINE=1 \ -DWITH_READLINE=1 \ -DMYSQL_UNIX_ADDR=/var/lib/mysql/mysql.sock \ -DMYSQL_TCP_PORT=3306 \ -DENABLED_LOCAL_INFILE=1 \ -DWITH_PARTITION_STORAGE_ENGINE=1 \ -DEXTRA_CHARSETS=all \ -DDEFAULT_CHARSET=utf8 \ -DDEFAULT_COLLATION=utf8_general_ci make && make install

初始化数据库

/usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3306/data --user=mysql /usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3307/data --user=mysql /usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/data/dbdata_3308/data --user=mysql

为什么要初始化数据库?
答:初始化的主要目的就是创建基础的数据库文件,例如生成MySQL库,表等.

授权数据库权限给mysql用户

setfacl -m u:mysql:rwx -R /data setfacl -m d:u:mysql:rwx -R /data

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/data 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 = 3306 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/data 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 = 3307 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/data 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 = 3308 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@rose \\r:\\m:\\s> [myisamchk] key_buffer_size = 512M sort_buffer_size = 512M read_buffer = 8M write_buffer = 8M [mysqlhotcopy] interactive-timeout [mysqld_safe] open-files-limit = 8192

更改环境变量

export PATH=/usr/local/mysql/bin:$PATH # 或者 vim /etc/profile PATH=/usr/local/mysql/bin:${PATH} source /etc/profile

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

更改原来密码（出于安全考虑，还需要删除系统中没有密码的帐号）

/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

登录MySQL并创建admin账户密码(停止mysql的时候需要使用)

/usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3306/mysql.sock GRANT SHUTDOWN ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password'; flush privileges; /usr/local/mysql/bin/mysql -uroot -ppassword -S /data/dbdata_3307/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;

mysqld_multi关闭进程(测试无效)

/usr/local/mysql/bin/mysqld_multi stop 1 /usr/local/mysql/bin/mysqld_multi stop 1-3

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做管理操作。其他的和单实例的管理没什么区别！

相关博文参考：
mysql多实例的配置和管理