mysql多实例安装有两种方法：
- 一种是每个实例分别使用自己的my.cnf文件；
- 一种是多个实例使用同一个my.cnf文件，放在/etc/路径下面，使用mysql自带的mysqld_multi工具管理
这里先介绍第一种方法，即每个实例使用自己的my.cnf文件：
上传文件并解压
[root@MySQL ~]# cd /usr/local/ [root@MySQL local]# ls mysql* mysql-5.7.9-linux-glibc2.5-x86_64.tar.gz [root@MySQL local]# tar zxvf mysql-5.7.9-linux-glibc2.5-x86_64.tar.gz
解压完毕之后创建软连接
[root@MySQL local]# ln -s mysql-5.7.9-linux-glibc2.5-x86_64 mysql [root@MySQL local]# cd mysql [root@MySQL mysql]# ll total 160 drwxr-xr-x 2 7161 wheel 4096 Oct 12 2015 bin -rw-r--r-- 1 7161 wheel 17987 Oct 12 2015 COPYING drwxr-xr-x 2 7161 wheel 4096 Oct 12 2015 docs drwxr-xr-x 3 7161 wheel 4096 Oct 12 2015 include -rw-r--r-- 1 7161 wheel 108028 Oct 12 2015 INSTALL-BINARY drwxr-xr-x 5 7161 wheel 4096 Oct 12 2015 lib drwxr-xr-x 4 7161 wheel 4096 Oct 12 2015 man -rw-r--r-- 1 7161 wheel 2478 Oct 12 2015 README drwxr-xr-x 28 7161 wheel 4096 Oct 12 2015 share drwxr-xr-x 2 7161 wheel 4096 Oct 12 2015 support-files
创建用户及组
[root@MySQL mysql]# groupadd mysql
[root@MySQL mysql]# useradd -r -g mysql mysql
为mysql路径下面的文件进行用户和组的修改
[root@MySQL mysql]# chown -R mysql . [root@MySQL mysql]# chgrp -R mysql .
创建数据文件和日志文件路径
[root@MySQL local]# mkdir /data/{3308,3307}/{data,log} [root@MySQL mysql]# chown -R mysql:mysql /data
创建my.cnf文件，分别在/data/3307和/data/3308路径下面：以3308为例
[root@MySQL 3308]# pwd /data/3308 [root@MySQL 3308]# cat my.cnf [client] port = 3308 socket = /data/3308/mysql.sock [mysqld] server_id=2 port = 3308 user = mysql character-set-server = utf8mb4 default_storage_engine = innodb log_timestamps = SYSTEM socket = /data/3308/mysql.sock basedir = /usr/local/mysql datadir = /data/3308/data pid-file = /data/3308/mysql.pid max_connections = 1000 max_connect_errors = 1000 table_open_cache = 1024 max_allowed_packet = 128M open_files_limit = 65535 #####====================================[innodb]============================== innodb_buffer_pool_size = 1024M innodb_file_per_table = 1 innodb_write_io_threads = 4 innodb_read_io_threads = 4 innodb_purge_threads = 2 innodb_flush_log_at_trx_commit = 1 innodb_log_file_size = 512M innodb_log_files_in_group = 2 innodb_log_buffer_size = 16M innodb_max_dirty_pages_pct = 80 innodb_lock_wait_timeout = 30 innodb_data_file_path=ibdata1:1024M:autoextend #####====================================[log]============================== log_error = /data/3308/log/mysql-error.log slow_query_log = 1 long_query_time = 1 slow_query_log_file = /data/3308/log/mysql-slow.log sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
初始化数据库：
mysql5.7.14版本初始化时候已经抛弃了defaults-file参数文件，所以在初始化时候指定配置文件会出错，同时必须保证datadir为空，这里的是5.7.9，所以可以指定defaults-file进行初始化
[root@MySQL mysql]# bin/mysqld --defaults-file=/data/3308/my.cnf --user=mysql --initialize-insecure --datadir=/data/3308/data --basedir=/usr/local/mysql [root@MySQL mysql]# bin/mysqld --defaults-file=/data/3307/my.cnf --user=mysql --initialize-insecure --datadir=/data/3307/data --basedir=/usr/local/mysql
设置加密连接 [root@MySQL mysql]# bin/mysql_ssl_rsa_setup --datadir=/data/3307/data [root@MySQL mysql]# bin/mysql_ssl_rsa_setup --datadir=/data/3308/data
创建启动脚本：
# cp /usr/local/mysql/support-files/mysql.server /etc/rc.d/init.d/mysqld3306
# cp /usr/local/mysql/support-files/mysql.server /etc/rc.d/init.d/mysqld3307
# cp /usr/local/mysql/support-files/mysql.server /etc/rc.d/init.d/mysqld3308
# chmod 755 /etc/rc.d/init.d/mysqld3306
# chmod 755 /etc/rc.d/init.d/mysqld3307
# chmod 755 /etc/rc.d/init.d/mysqld3308
# vi /etc/rc.d/init.d/mysqld3308 #编辑 （3306,3307同理） basedir=/usr/local/mysql #MySQL程序安装路径 datadir=/data/3308 #MySQl数据库存放目录 （这里注意要填my.cnf的上一层目录） 修改 $bindir/mysqld_safe --datadir="$datadir" --pid-file="$mysqld_pid_file_path" $other_args >/dev/null 2>&1 & 变成 $bindir/mysqld_safe --defaults-file="$datadir/my.cnf" --pid-file="$mysqld_pid_file_path" $other_args >/dev/null 2>&1 &
启动数据库：
# service mysqld3306 start
# service mysqld3307 start
# service mysqld3308 start
多实例登陆，指定socket
mysql -S /data/3306/mysql.sock -uroot -p
mysql远程连接方式：
[root@MySQL bin]# mysql -uroot -p -P3308 -h localhost
添加自动启动
shell> cat /etc/rc.local
shell> echo "/usr/local/mysql/bin/mysqld_multi --defaults-extra-file=/etc/my.cnf start 3306,3307" >> /etc/rc.local
开启防火墙
shell> vi /etc/sysconfig/iptables
-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 3307 -j ACCEPT
shell> service iptables restart
/*防火墙基本命令:
0）查看当前规则
iptables -L -n --line-number
service iptables status
1） 临时生效，重启后复原
保存: service iptables save
开启： service iptables start
关闭： service iptables stop
重启: service iptables restart
2） 永久性生效，重启后不会复原
开启： chkconfig iptables on
关闭： chkconfig iptables off
*/
第二种方式：
这种方式只是修改/etc/my.cnf文件，配置如下，配置多个实例，分别对每个实例进行初始化，初始化不需要指定defaults-file，默认为/etc/my.cnf。
多实例启动方式：
mysqld_multi start {port1,port2,...}
数据库登陆和关闭的方式和第一种一样
多实例配置文件
[root@MySQL log]# cat /etc/my.cnf
[mysqld_multi] mysqld = /usr/local/mysql/bin/mysqld_safe mysqladmin = /usr/local/mysql/bin/mysqladmin #user = root #password = rootpwd [mysqld3306] port = 3306 server_id = 3306 basedir =/usr/local/mysql datadir =/data/3306/data log-bin=/data/3306/log/mysql-bin socket =/data/3306/mysql.sock log-error =/data/3306/log/mysqld.log pid-file =/data/3306/mysqld.pid [mysqld3307] port = 3307 server_id = 3307 basedir =/usr/local/mysql datadir =/data/3307/data log-bin=/data/3307/log/mysql-bin socket =/data/3307/mysql.sock log-error =/data/3307/log/mysqld.log pid-file =/data/3307/mysqld.pid
遇到错误：
[root@MySQL mysql]# bin/mysqld --initialize-insecure --defaults-file=/data/3306/my.cnf --user=mysql --datadir=/data/3306/data --basedir=/usr/local/mysql
2017-06-26T12:33:38.809622Z 0 [ERROR] unknown variable 'defaults-file=/data/3306/my.cnf' 2017-06-26T12:33:38.809657Z 0 [ERROR] Aborting
这里是个BUG，无论在启动还是初始化，必须把defaults-file这个参数放在第一位，否则就会报错，正确如下：
[root@MySQL mysql]# bin/mysqld --defaults-file=/data/3306/my.cnf --user=mysql --initialize-insecure --datadir=/data/3306/data --basedir=/usr/local/mysql mysqld: [Warning] World-writable config file '/data/3306/my.cnf' is ignored. 2017-06-26T12:34:12.901074Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2017-06-26T12:34:13.520944Z 0 [Warning] InnoDB: New log files created, LSN=45790 2017-06-26T12:34:13.616526Z 0 [Warning] InnoDB: Creating foreign key constraint system tables. 2017-06-26T12:34:13.709685Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: c2f799c6-5a6b-11e7-b7ff-08002714955b. 2017-06-26T12:34:13.714696Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened. 2017-06-26T12:34:13.716948Z 1 [Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
