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

1. 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;
   

2. 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

3. 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)

1. 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
   

2. 导入 master 导出的数据库：

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

3. 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
   

4. 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