mysql 基于 master-master 的双机热备配置

master-master 就是两台服务器互为主从： 

master1-slave(master2) && master2-slave(master1)
master1: 192.168.100.191
master2: 192.168.100.166

master1-slave(master2)

mysql 版本最好一致

设置 master1

创建给 slave 登录用的用户名密码:

mysql> GRANT REPLICATION SLAVE ON *.* TO 'backup'@'192.168.100.166' IDENTIFIED BY 'yNZE7fK9*@aMA?*ppF';

# humanreadable
mysql> # grant replication slave on *.* to 'backup'@'192.168.100.166' identified by 'yNZE7fK9*@aMA?*ppF';

mysql> create database hello default charset utf8;

配置 my.cnf

# vim /etc/my.cnf
[mysqld]
server-id=1    #主机id，整数
#开启二进制日志，并且名称为 /var/lib/mysql/mysql-bin.***
# 如果是个路径则，保存到该路径下(log-bin=/var/log/mysql-bin.log  -> /var/log/mysql-bin.***)
log-bin=mysql-bin
read-only=0  #主机读写权限，读写都可以
binlog-do-db=hello   #记录日志的数据库：需要的备份数据，多个写多行
# binlog-do-db=hello2
binlog-ignore-db=mysql #不记录日志的数据库：不需要备份的数据库，多个写多行
binlog-ignore-db=test
binlog-ignore-db=information_schema

# 自增字段奇数递增，防止冲突（1, 3, 5, ...,）
auto-increment-increment = 2  # 每次递增的步长
auto-increment-offset = 1  # 初始值

重启 mysql: 

serivce mysqld restart

导出数据库

锁定数据库，不要退出 mysql shell

mysql>FLUSH TABLES WITH READ LOCK;
mysql># flush tables with read lock;

新开一个终端，导出数据库

mysqldump --master-data -uroot -p hello > hello.sql

查看主服务器的状态

mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000001
Position: 98
Binlog_Do_DB: hello
Binlog_Ignore_DB: mysql,test,information_schema
1 row in set (0.00 sec)

ERROR:
No query specified

记下 Position 和 File 的值。 解锁

mysql> UNLOCK TABLES;
mysql> # unlock tables;

设置 slave(master2)

编辑 my.cnf

# vim /etc/my.cnf

[mysqld]
server-id=2
log-bin=mysql-bin
replicate-do-db =hello #只复制某个库，多个写多行
replicate-ignore-db=mysql #不复制某个库
replicate-ignore-db=test
replicate-ignore-db=information_schema
relay-log=mysqld-relay-bin  # 开启日志中继
log-slave-updates  # slave将复制事件写进自己的二进制日志
#5.5
#log-slave-updates = ON
#5.1
#log-slave-updates = 1

导入 master 导出的数据库：

mysql> create database hello default charset utf8;
mysql -uroot -p hello < hello.sql

配置 master 信息：

mysql> slave stop;

mysql> CHANGE MASTER TO
-> MASTER_HOST='192.168.100.191', //主服务器的IP地址
-> MASTER_USER='backup', //同步数据库的用户
-> MASTER_PASSWORD='yNZE7fK9*@aMA?*ppF', //同步数据库的密码
-> MASTER_CONNECT_RETRY=60,  // 如果从服务器发现主服务器断掉，重新连接的时间差(秒)
-> MASTER_LOG_FILE='mysql-bin.000001', //主服务器二进制日志的文件名(前面要求记住的 File 参数)
-> MASTER_LOG_POS=98; //日志文件的开始位置(前面要求记住的 Position 参数)

mysql> CHANGE MASTER TO MASTER_HOST='192.168.100.191', MASTER_USER='backup', MASTER_PASSWORD='yNZE7fK9*@aMA?*ppF', MASTER_CONNECT_RETRY=60, MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=98;

mysql > slave start;

重启 master, slave: 

service mysqld restart

查看 slave 状态：

进入 slave mysql:

mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Connecting to master
Master_Host: 192.168.100.191
Master_User: backup
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 98
Relay_Log_File: mysqld-relay-bin.000001
Relay_Log_Pos: 98
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: hello
Replicate_Ignore_DB: mysql,test,information_schema
Exec_Master_Log_Pos: 98
Relay_Log_Space: 98
Until_Log_Pos: 0
Seconds_Behind_Master: NULL
1 row in set (0.00 sec)

注意一定要有下面两项，没有的话查看错误日志(less /var/log/mysqld.log)：

Slave_IO_Running: Yes
Slave_SQL_Running: Yes

测试

master 服务器

mysql> use hello;
Database changed
mysql> create table test(id int);
mysql> insert int test set id=1;

mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000002  # 注意这里
Position: 276    # 注意这里
Binlog_Do_DB: hello
Binlog_Ignore_DB: mysql,test,information_schema
1 row in set (0.00 sec)

slave 服务器

mysql> use hello;
mysql> show tables;
+-----------------+
| Tables_in_hello |
+-----------------+
| test            |
+-----------------+
1 row in set (0.00 sec)

mysql> select * from test;
+------+
| id   |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.100.191
Master_User: backup
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002  # 跟 master 一样
Read_Master_Log_Pos: 276  # 跟 master 一样
Relay_Log_File: mysqld-relay-bin.000003
Relay_Log_Pos: 413
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: hello
Replicate_Ignore_DB: mysql,test,information_schema
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 276
Relay_Log_Space: 413
Seconds_Behind_Master: 0
1 row in set (0.00 sec)

master2-slave(master1)

master2:

mysql> grant replication slave on *.* to 'backup'@'192.168.100.191' identified by 'yNZE7fK9*@aMA?*ppF';
mysql> flush tables with read lock;
mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000002
Position: 276
Binlog_Do_DB:
Binlog_Ignore_DB:
mysql> unlock tables;

vim /etc/my.cnf:

# as master
#开启二进制日志，并且名称为 /var/log/mysql/mysql-bin.***
log-bin=mysql-bin
read-only=0  #主机读写权限，读写都可以
binlog-do-db=hello   #记录日志的数据库：需要的备份数据，多个写多行
binlog-ignore-db=mysql #不记录日志的数据库：不需要备份的数据库，多个写多行
binlog-ignore-db=test
binlog-ignore-db=information_schema

# 自增字段偶数递增，防止冲突（2, 4, 6, ...,）
auto-increment-increment = 2  # 每次递增的步长
auto-increment-offset = 2  # 初始值

service mysqld restart

slave:

mysql> slave stop;

mysql>  CHANGE MASTER TO MASTER_HOST='192.168.100.166', MASTER_USER='backup', MASTER_PASSWORD='yNZE7fK9*@aMA?*ppF', MASTER_CONNECT_RETRY=60, MASTER_LOG_FILE='mysql-bin.000002, MASTER_LOG_POS=276';

mysql> slave start;

vim /etc/my.cnf

# as slave
replicate-do-db =hello #只复制某个库，多个写多行
replicate-ignore-db=mysql #不复制某个库
replicate-ignore-db=test
replicate-ignore-db=information_schema
relay-log=mysqld-relay-bin  # 开启日志中继
log-slave-updates  # slave将复制事件写进自己的二进制日志

serivce mysqld restart

测试

master2:

mysql> use hello;
mysql> insert into test set id=2;
mysql> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
+------+
2 rows in set (0.00 sec)
mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000003
Position: 187
Binlog_Do_DB: hello
Binlog_Ignore_DB: mysql,test,information_schema
1 row in set (0.00 sec)

slave:

mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.100.166
Master_User: backup
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000003
Read_Master_Log_Pos: 187
Relay_Log_File: mysqld-relay-bin.000003
Relay_Log_Pos: 324
Relay_Master_Log_File: mysql-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: hello
Replicate_Ignore_DB: mysql,test,information_schema
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 187
Relay_Log_Space: 324
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Seconds_Behind_Master: 0

mysql> use hello;

mysql> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
+------+
2 rows in set (0.00 sec)

最后的配置文件

master1:

# /etc/my.cnf
[mysqld]

# as master
server-id=1    #主机id，整数
#开启二进制日志，并且名称为 /var/lib/mysql/mysql-bin.***
log-bin=mysql-bin
read-only=0  #主机读写权限，读写都可以
binlog-do-db=hello   #记录日志的数据库：需要的备份数据，多个写多行
# binlog-do-db=hello2
binlog-ignore-db=mysql #不记录日志的数据库：不需要备份的数据库，多个写多行
binlog-ignore-db=test
binlog-ignore-db=information_schema

# as slave
replicate-do-db =hello #只复制某个库，多个写多行
replicate-ignore-db=mysql #不复制某个库
replicate-ignore-db=test
replicate-ignore-db=information_schema
relay-log=mysqld-relay-bin  # 开启日志中继
log-slave-updates  # slave将复制事件写进自己的二进制日志
# 自增字段奇数递增，防止冲突（1, 3, 5, ...,）
auto-increment-increment = 2  # 每次递增的步长
auto-increment-offset = 1  # 初始值

master2:

# /etc/my.cnf
[mysqld]

# as slave
server-id=2
log-bin=mysql-bin
replicate-do-db =hello #只复制某个库，多个写多行
replicate-ignore-db=mysql #不复制某个库
replicate-ignore-db=test
replicate-ignore-db=information_schema
relay-log=mysqld-relay-bin  # 开启日志中继
log-slave-updates  # 示slave将复制事件写进自己的二进制日志

# as master
#开启二进制日志，并且名称为 /var/lib/mysql/mysql-bin.***
log-bin=mysql-bin
read-only=0  #主机读写权限，读写都可以
binlog-do-db=hello   #记录日志的数据库：需要的备份数据，多个写多行
# binlog-do-db=hello2
binlog-ignore-db=mysql #不记录日志的数据库：不需要备份的数据库，多个写多行
binlog-ignore-db=test
binlog-ignore-db=information_schema

# 自增字段偶数递增，防止冲突（2, 4, 6, ...,）
auto-increment-increment = 2  # 每次递增的步长
auto-increment-offset = 2  # 初始值