什么是实例?
进程+多个线程+预分配的内存结构
MySQL多实例:
多个进程+多个线程+多个预分配内存结构
多个配置文件:
1)多个端口
2)多个数据目录
3)多个socket文件
./mysql_install_db --user --basedir --datadir
1)创建多个数据目录
[root@elk01 ~]# mkdir -p /data/330{7..9}
2)创建多个配置文件
vim /data/3307/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /data/3307/data
port = 3307
server_id = 7
log-bin = /data/3307/data/mysql-bin
log_error = /data/3307/data/mysql.err
socket = /data/3307/data/mysql.sock
vim /data/3308/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /data/3308/data
port = 3308
server_id = 8
log-bin = /data/3308/data/mysql-bin
log_error = /data/3308/data/mysql.err
socket = /data/3308/data/mysql.sock
vim /data/3309/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /data/3309/data
port = 3309
server_id = 9
log-bin = /data/3309/data/mysql-bin
log_error = /data/3309/data/mysql.err
socket = /data/3309/data/mysql.sock
3)初始化
[root@elk01 scripts]# ./mysql_install_db --user=mysql --basedir=/usr/local/mysql --datadir=/data/3307/data
[root@elk01 scripts]# ./mysql_install_db --user=mysql --basedir=/usr/local/mysql --datadir=/data/3308/data
[root@elk01 scripts]# ./mysql_install_db --user=mysql --basedir=/usr/local/mysql --datadir=/data/3309/data
4)启动MySQL
[root@elk01 scripts]# mysqld_safe --defaults-file=/data/3307/my.cnf &
[root@elk01 scripts]# mysqld_safe --defaults-file=/data/3308/my.cnf &
[root@elk01 scripts]# mysqld_safe --defaults-file=/data/3309/my.cnf &
5)设置密码
[root@elk01 scripts]# mysqladmin -uroot -S /data/3307/data/mysql.sock password '3307'
[root@elk01 scripts]# mysqladmin -uroot -S /data/3308/data/mysql.sock password '3308'
[root@elk01 scripts]# mysqladmin -uroot -S /data/3309/data/mysql.sock password '3309'
6)查看
[root@elk01 scripts]# mysql -uroot -p3307 -S /data/3307/data/mysql.sock -e "show variables like 'server_id'"
Warning: Using a password on the command line interface can be insecure.
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id | 7 |
+---------------+-------+
[root@elk01 scripts]# mysql -uroot -p3308 -S /data/3308/data/mysql.sock -e "show variables like 'server_id'"
Warning: Using a password on the command line interface can be insecure.
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id | 8 |
+---------------+-------+
[root@elk01 scripts]# mysql -uroot -p3309 -S /data/3309/data/mysql.sock -e "show variables like 'server_id'"
Warning: Using a password on the command line interface can be insecure.
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id | 9 |
+---------------+-------+
[root@elk01 scripts]# vim /usr/local/bin/mysql3307
mysql -uroot -p3307 -S /data/3307/data/mysql.sock
[root@elk01 scripts]# vim /usr/local/bin/mysql3308
mysql -uroot -p3308 -S /data/3308/data/mysql.sock
[root@elk01 scripts]# vim /usr/local/bin/mysql3309
mysql -uroot -p3309 -S /data/3309/data/mysql.sock
[root@elk01 scripts]# chmod +x /usr/local/bin/mysql330*
在没有备份的情况下表损坏企业案例:
1)找开发拿到建表语句
2)创建一个新的MySQL实例,创建表
3)删除独立表空间
mysql> alter table city_new discard tablespace;
4)拷贝旧表的表空间文件到新表下
5)导入独立表空间
mysql> alter table city_new import tablespace;