mysql5.6搭建主从复制

使用MySQL 5.6，搭建主从复制。关于5.6的安装，可以参考《MySQL 5.6 rpm安装方法和碰见的问题》。

 

主库创建slave用户，设置复制权限，

mysql> create user 'slave'@'1.1.1.2' identified by 'root';

Query OK, 0 rows affected (0.00 sec)

• 1. mysql> grant replication slave on *.* to 'slave'@'1.1.1.2' identified by 'root';
  2. Query OK, 0 rows affected (0.00 sec)

 

1. 编辑my.cnf配置文件，设置主库server-id=1，定义需要复制的库为test，忽略mysql数据库

1. [root@vm-kvm10000-app mysql]# vi /etc/my.cnf
2. [mysqld]
3. server-id=1
4. log-bin=mysql-bin
5. binlog_do_db=test
6. binlog_ignore_db=mysql

 

1. 重启主库MySQL服务，

1. [root@vm-kvm10000-app mysql]# service mysql restart
2. Shutting down MySQL.. SUCCESS!
3. Starting MySQL. SUCCESS!

 

1. 看一下主库状态，

1. mysql> show master status;
2. +------------------+----------+--------------+------------------+-------------------+
3. | File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
4. +------------------+----------+--------------+------------------+-------------------+
5. | mysql-bin.000002 |      120 | test         | mysql            |                   |
6. +------------------+----------+--------------+------------------+-------------------+
7. 1 row in set (0.00 sec)

 

1. 或者
2. mysql> show master status \G
3. *************************** 1. row ***************************
4. File: mysql-bin.000002
5. Position: 120
6. Binlog_Do_DB: test
7. Binlog_Ignore_DB: mysql
8. Executed_Gtid_Set:
9. 1 row in set (0.00 sec)

 

1. 从库，编辑my.cnf配置，设置server-id=2，区别于主库，

1. [root@vm-kvm10001-app mysql]# vi /etc/my.cnf
2. [mysqld]
3. server-id=2

 

1. 重启MySQL服务，

1. [root@vm-kvm10001-app mysql]# service mysql restart
2. Shutting down MySQL.. SUCCESS!
3. Starting MySQL. SUCCESS!

 

1. 设置主库信息，

1. mysql> change master to master_host='1.1.1.1',master_user='slave',master_password='root',master_log_file='mysql-bin.000001',master_log_pos=120,master_connect_retry=10;
2. Query OK, 0 rows affected, 2 warnings (0.03 sec)

 

1. 检索从库状态，

1. mysql> show slave status \G;
2. *************************** 1. row ***************************
3. Slave_IO_State:
4. Master_Host: 10.221.3.129
5. Master_User: slave
6. Master_Port: 3306
7. Connect_Retry: 10
8. Master_Log_File: mysql-bin.000001
9. Read_Master_Log_Pos: 120
10. Relay_Log_File: vm-kvm11853-app-relay-bin.000001
11. Relay_Log_Pos: 4
12. Relay_Master_Log_File: mysql-bin.000001
13. Slave_IO_Running: No
14. Slave_SQL_Running: No
15. Replicate_Do_DB:
16. Replicate_Ignore_DB:
17. Replicate_Do_Table:
18. Replicate_Ignore_Table:
19. Replicate_Wild_Do_Table:
20. Replicate_Wild_Ignore_Table:
21. Last_Errno: 0
22. Last_Error:
23. Skip_Counter: 0
24. Exec_Master_Log_Pos: 120
25. Relay_Log_Space: 120
26. Until_Condition: None
27. Until_Log_File:
28. Until_Log_Pos: 0
29. Master_SSL_Allowed: No
30. Master_SSL_CA_File:
31. Master_SSL_CA_Path:
32. Master_SSL_Cert:
33. Master_SSL_Cipher:
34. Master_SSL_Key:
35. Seconds_Behind_Master: NULL
36. Master_SSL_Verify_Server_Cert: No
37. Last_IO_Errno: 0
38. Last_IO_Error:
39. Last_SQL_Errno: 0
40. Last_SQL_Error:
41. Replicate_Ignore_Server_Ids:
42. Master_Server_Id: 0
43. Master_UUID:
44. Master_Info_File: /var/lib/mysql/master.info
45. SQL_Delay: 0
46. SQL_Remaining_Delay: NULL
47. Slave_SQL_Running_State:
48. Master_Retry_Count: 86400
49. Master_Bind:
50. Last_IO_Error_Timestamp:
51. Last_SQL_Error_Timestamp:
52. Master_SSL_Crl:
53. Master_SSL_Crlpath:
54. Retrieved_Gtid_Set:
55. Executed_Gtid_Set:
56. Auto_Position: 0
57. 1 row in set (0.00 sec)

 

1. 其中最重要的就是，这两个参数，要求YES，但此处为NO，

1. Slave_IO_Running: No
2. Slave_SQL_Running: No

 

1. 检索错误日志，提示无法找见./performance_schema/cond_instances.frm文件，

1. [root@vm-kvm10001-app mysql]# vm-kvm10001-app.err
2. 2017-08-29 16:10:37 22933 [ERROR] /usr/sbin/mysqld: Can't find file: './performance_schema/cond_instances.frm' (errno: 13 - Permission denied)

 

1. 看一下其目录，发现performance_schema文件夹，是root权限，mysql用户无法访问，因此需要修改一下其权限，

1. [root@vm-kvm10001-app mysql]# ls -rlht
2. total 109M
3. ...
4. drwx------ 2 root  root  4.0K Aug 29 15:05 performance_schema
5. ...

 

1. [root@vm-kvm10001-app mysql]# chown -R mysql:mysql *

 

1. [root@vm-kvm10001-app mysql]# ls -rlht
2. total 109M
3. ...
4. drwx------ 2 mysql mysql 4.0K Aug 29 15:05 performance_schema

1. ...

 

1. 重启服务，

1. [root@vm-kvm10001-app mysql]# service mysql restart
2. Shutting down MySQL.... SUCCESS!
3. Starting MySQL. SUCCESS!

 

1. 再看从库状态，

1. mysql> show slave status \G
2. *************************** 1. row ***************************
3. ...
4. Slave_IO_Running: Yes
5. Slave_SQL_Running: Yes
6. ...

 

1. 主库导出数据，用于导入从库，首先需要设置读锁，避免数据不一致，

1. mysql> flush tables with read lock;

 

1. mysql> show master logs;
2. +------------------+-----------+
3. | Log_name         | File_size |
4. +------------------+-----------+
5. | mysql-bin.000001 |       143 |
6. | mysql-bin.000002 |       222 |
7. | mysql-bin.000003 |       545 |
8. +------------------+-----------+
9. 3 rows in set (0.00 sec)

 

1. 执行mysqldump将test库，导出test.sql文件，

1. [root@vm-kvm10000-app mysql]# mysqldump -uroot -p -B test > test.sql

 

1. 然后解锁表，

1. mysql> unlock tables;

 

1. 从库执行导入，

1. [root@vm-kvm10001-app mysql]# mysql -uroot -p < test.sql

 

1. 要确保从库，这两个值正确，

1. Slave_IO_Running: Yes    
2. Slave_SQL_Running: Yes

 

1. 此时就完成了主从复制，向主库插入一条记录，

1. mysql> INSERT INTO test
2.     -> (id, name)
3.     -> VALUES
4.     -> (1, "a");
5. Query OK, 1 rows affected (0.00 sec)

 

1. 从库中可以检索出来，

1. mysql> select * from test;
2. +-------+--------+
3. |     id    |  name  |
4. +-------+--------+
5. |      1    |     a      |
6. +-------+--------+

 

 

1. 总结：
2. 1. MySQL相关文件、文件夹需要的权限，可能会因为不正确，例如需要mysql权限，但却是root，导致数据库异常。
3. 2. 主从复制，需要关注从库，这两个参数值，需要均为YES，出现NO，则可以检索错误日志，进一步定位。
4. Slave_IO_Running: Yes
5. Slave_SQL_Running: Yes