#mysql双主同步的实现
##环境描述
``Centos7.3版本``
``192.190.10.153 安装keepalived、mysql``
``192.190.10.154 安装keepalived、mysql``
##环境部署
### 1.部署
``---------------192.190.10.153服务器操作记录---------------``
```linux
在my.cnf文件的[mysqld]配置区域添加下面内容：
[root@SpinfoServer ~]# vim /opt/Spinfo/mysql/my.cnf
server-id = 1 // mysql标示，不能出现重复
log-bin = mysql-bin // 开启log-bin二进制日志文件
sync_binlog = 1
binlog_ignore_db = mysql,information_schema // 不进行同步的数据库
binlog_checksum = none
binlog_format = mixed
auto-increment-increment = 2
auto-increment-offset = 1
slave-skip-errors = all
(注：修改完成后需重启mysql)
// 进入mysql
数据同步授权（iptables防火墙开启3306端口）这样I/O线程就可以以这个用户的身份连接到主服务器，并且读取它的二进制日志。
MariaDB [test]> grant replication slave,replication client on *.* to 'root'@'%' identified by "root";
Query OK, 0 rows affected (0.00 sec)
MariaDB [test]> flush privileges;
Query OK, 0 rows affected (0.00 sec)
最好将库锁住，仅仅允许读，以保证数据一致性；待主主同步环境部署后再解锁；
锁住后，就不能往表里写数据，但是重启mysql服务后就会自动解锁！
MariaDB [test]> flush tables with read lock; //注意该参数设置后，如果自己同步对方数据，同步前一定要记得先解锁！
Query OK, 0 rows affected (0.00 sec)
查看log bin日志和pos值位置
MariaDB [test]> show master status;
+------------------+----------+--------------+--------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+--------------------------+
| mysql-bin.000159 | 245 | | mysql,information_schema |
+------------------+----------+--------------+--------------------------+
1 row in set (0.00 sec)
```
``---------------192.190.10.154服务器操作记录---------------``
```linux
在my.cnf文件的[mysqld]配置区域添加下面内容：
[root@SpinfoServer ~]# vim /opt/Spinfo/mysql/my.cnf
server-id = 2
log-bin = mysql-bin
sync_binlog = 1
binlog_ignore_db = mysql,information_schema
binlog_checksum = none
binlog_format = mixed
auto-increment-increment = 2
auto-increment-offset = 2
slave-skip-errors = all
(注：修改完成后需重启mysql)
// 进入mysql
MariaDB [test]> grant replication slave,replication client on *.* to 'root'@'%' identified by "root";
Query OK, 0 rows affected (0.00 sec)
MariaDB [test]> flush privileges;
Query OK, 0 rows affected (0.00 sec)
MariaDB [test]> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
MariaDB [test]> show master status;
+------------------+----------+--------------+--------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+--------------------------+
| mysql-bin.000162 | 245 | | mysql,information_schema |
+------------------+----------+--------------+--------------------------+
1 row in set (0.00 sec)
```
``---------------192.190.10.153服务器做同步操作---------------``
```linux
MariaDB [test]> unlock tables; //先解锁，将对方数据同步到自己的数据库中
MariaDB [test]> slave stop；
MariaDB [test]> change master to master_host='192.190.10.154',master_user='root',master_password='root',master_log_file='mysql-bin.000162',master_log_pos=245;
// 注：这里的host、log_file、log_pos都是另一台机器的
Query OK, 0 rows affected, 2 warnings (0.01 sec)
MariaDB [test]> start slave;
Query OK, 0 rows affected (0.01 sec)
查看同步状态，如下出现两个“Yes”，表明同步成功！
MariaDB [test]> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.190.10.154
Master_User: root
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000162
Read_Master_Log_Pos: 245
Relay_Log_File: SpinfoServer-relay-bin.000007
Relay_Log_Pos: 529
Relay_Master_Log_File: mysql-bin.000162
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
......
Master_Server_Id: 2
1 row in set (0.00 sec)
这样，master1就和master2实现了主从同步，即master1同步master2的数据。
```
``---------------192.190.10.154服务器做同步操作---------------``
```linux
MariaDB [test]> unlock tables;
MariaDB [test]> slave stop；
MariaDB [test]> change master to master_host='192.190.10.153',master_user='root',master_password='root',master_log_file='mysql-bin.000159',master_log_pos=245;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
MariaDB [test]> start slave;
Query OK, 0 rows affected (0.01 sec)
MariaDB [test]> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.190.10.153
Master_User: root
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000159
Read_Master_Log_Pos: 245
Relay_Log_File: SpinfoServer-relay-bin.000007
Relay_Log_Pos: 529
Relay_Master_Log_File: mysql-bin.000159
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
......
Master_Server_Id: 1
1 row in set (0.00 sec)
这样，master2就和master1实现了主从同步，即master2也同步master1的数据。
```
### 2.验证
``-----------------主主同步效果验证---------------------``
```linux
1）在192.190.10.153数据库上写入新数据
MariaDB [test]> create table if not exists ha (
-> id int(10) PRIMARY KEY AUTO_INCREMENT,
-> name varchar(50) NOT NULL);
Query OK, 0 rows affected (0.04 sec)
MariaDB [test]> insert into ha values(1, "刘德华");
Query OK, 1 row affected (0.00 sec)
MariaDB [test]> insert into ha values(2, "周杰伦");
Query OK, 1 row affected (0.00 sec)
MariaDB [test]> select * from ha;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 刘德华 |
| 2 | 周杰伦 |
+----+-----------+
2 rows in set (0.00 sec)
2）在192.190.10.154上查看数据是否已经同步
MariaDB [test]> show tables;
+----------------+
| Tables_in_test |
+----------------+
| ha |
| newtable |
+----------------+
2 rows in set (0.01 sec)
MariaDB [test]> select * from ha;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 刘德华 |
| 2 | 周杰伦 |
+----+-----------+
2 rows in set (0.00 sec)
3）在192.190.10.154数据库上写入新数据
MariaDB [test]> insert into ha values(3, "林俊杰"),(4, "陈奕迅");
Query OK, 2 rows affected (0.01 sec)
Records: 2 Duplicates: 0 Warnings: 0
MariaDB [test]> select * from ha;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 刘德华 |
| 2 | 周杰伦 |
| 3 | 林俊杰 |
| 4 | 陈奕迅 |
+----+-----------+
4 rows in set (0.00 sec)
4）在192.190.10.153数据库上查看数据是否同步
MariaDB [test]> select * from ha;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 刘德华 |
| 2 | 周杰伦 |
| 3 | 林俊杰 |
| 4 | 陈奕迅 |
+----+-----------+
4 rows in set (0.00 sec)
（此处只做了添加数据时的验证，你也可以进行修改和删除的验证）
```
#####至此，Mysql主主同步环境已经实现。
