mysqld_multi实现多主一从复制

目的：两台主mysql数据库复制到一台从mysql 服务器上

两台主库的ip为
172.16.27.23
172.16.27.25

一台从库的ip为
172.16.27.21

1. 在两台主库的配置文件内加入下面几条，两台都要加

server-id = 1
log-bin =
mysql-bin
binlog_format=mixed

2.
加完后保存退出，登录两台数据库建立用来同步的用户并给他授权

GRANT REPLICATION SLAVE ON * . * TO 'REPL' @ '
172.16.27.21' IDENTIFIED BY '123456';
做完授权后，重新启动mysql
，查看binlog 是否已经开始生效

3. 然后在两台主mysql数据库锁表 并记录
pos值和当前的binlog文件

172.16.27.23:

mysql> FLUSH TABLES WITH READ LOCK;
Query OK, 0
rows affected (0.00 sec)

mysql> SHOW MASTER
STATUS;
+------------------+----------+--------------+------------------+
|
File | Position | Binlog_Do_DB | Binlog_Ignore_DB
|
+------------------+----------+--------------+------------------+
|
mysql-bin.000070 | 217643
| | |
+------------------+----------+--------------+------------------+
1
row in set (0.00 sec)

172.16.27.25:

mysql> FLUSH TABLES WITH READ LOCK;
Query OK, 0
rows affected (0.00 sec)

mysql> SHOW MASTER
STATUS;
+---------------+----------+--------------+------------------+
|
File | Position | Binlog_Do_DB | Binlog_Ignore_DB
|
+---------------+----------+--------------+------------------+
|
binlog.000002 | 13407
| | |
+---------------+----------+--------------+------------------+
1
row in set (0.00 sec)

4. 用mysqldump
或者其他方法将要同步的两台主mysql数据库导出 。

5. 修改从库的my.cnf 配置文件

[mysqld_multi]
mysqld =
/usr/local/mysql/bin/mysqld_safe
mysqladmin =
/usr/local/mysql/bin/mysqladmin
user =
root
password =123456
log =
/usr/local/mysql/mysqld_multi.log

[mysqld1]
port =
3307
socket = /tmp/mysql.sock1
skip-locking
key_buffer_size =
384M
max_allowed_packet = 1M
table_open_cache = 512
sort_buffer_size =
2M
read_buffer_size = 2M
read_rnd_buffer_size =
8M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size
= 32M
thread_concurrency = 8

pid-file =
/usr/local/mysql/data1/mysqld1.pid
datadir =
/usr/local/mysql/data1
log
=/usr/local/mysql/data1/mysql_multi_1.log
user =
mysql
log-bin = mysql1-bin
server-id = 2
master-host
= 172.16.27.23
master-port = 3306
master-user =
repl
master-password = 123456
replicate-do-db = product
binlog_format
= mixed

[mysqld2]
port = 3308
socket =
/tmp/mysql.sock2
skip-locking
key_buffer_size = 384M
max_allowed_packet
= 1M
table_open_cache = 512
sort_buffer_size = 2M
read_buffer_size =
2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size =
64M
thread_cache_size = 8
query_cache_size = 32M
thread_concurrency =
8

pid-file = /usr/local/mysql/data2/mysqld2.pid
datadir
= /usr/local/mysql/data2
log
=/usr/local/mysql/data2/mysql_multi_2.log
user =
mysql
log-bin = mysql2-bin
server-id = 3
master-host
= 172.16.27.25
master-port = 3306
master-user =
repl
master-password = 123456
replicate-do-db = my_blog
binlog_format
= mixed

6.初始化数据库

/usr/local/mysql/bin/mysql_install_db
--datadir=/usr/local/mysql/data1 --user=mysql
&
/usr/local/mysql/bin/mysql_install_db --datadir=/usr/local/mysql/data2
--user=mysql &

7. 启动mysql ，这时就不能按照以前那样启动了，现在启动时候需要
mysqld_multi这个程序 具体做法如下

/usr/local/mysql/bin/mysqld_multi
--config-file=/etc/my.cnf start 1-2
/usr/local/mysql/bin/mysqld_multi
--config-file=/etc/my.cnf start 1,2
这样也可以

8.下一步就是要导入数据库了，不过要先登录mysql建立数据库

mysql -u root -S /tmp/mysql.sock1
mysql> create
database product;
mysql>exit
mysql -u root -S /tmp/mysql.sock1 produt
< /root/product.sql

mysql -u root -S /tmp/mysql.sock2
mysql>
create database my_blog;
mysql>exit
mysql -u root -S /tmp/mysql.sock2
produt < /root/my_blog.sql

9 .重启两个mysql

/usr/local/mysql/bin/mysqld_multi
--config-file=/etc/my.cnf report 1,2

10
.重启后分别进入两个进程来启动同步。