为什么80%的码农都做不了架构师？>>> 
一 、环境信息
主库 172.104.29.30/3306
备库 172.104.29.192/3306
二、 主从切换
说明：主，备节点都要创建 Replication 用户
mysql> GRANT REPLICATION SLAVE ON *.* TO 'rpl'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.00 sec)
三、查询从库状态
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.104.29.30
Master_User: rpl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-master.000001
Read_Master_Log_Pos: 696
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 562
Relay_Master_Log_File: mysql-master.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 696
Relay_Log_Space: 736
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 30
Master_UUID: 75fff4c2-f9af-11e7-b458-f23c91cd60a2
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
四、查询主库状态
mysql> show slave hosts;
+-----------+------+------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID |
+-----------+------+------+-----------+--------------------------------------+
| 192 | | 3306 | 30 | d6a09587-f9ca-11e7-b50b-f23c91cd54d8 |
+-----------+------+------+-----------+--------------------------------------+
1 row in set (0.00 sec)
五、从库: 停止 IO_THREAD 线程
说明：172.104.29.192上操作
mysql> stop slave IO_THREAD;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 172.104.29.30
Master_User: rpl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-master.000002
Read_Master_Log_Pos: 120
Relay_Log_File: mysqld-relay-bin.000004
Relay_Log_Pos: 286
Relay_Master_Log_File: mysql-master.000002
Slave_IO_Running: No
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 120
Relay_Log_Space: 626
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 30
Master_UUID: 75fff4c2-f9af-11e7-b458-f23c91cd60a2
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
六、激活从库(从库上操作)
说明：172.104.29.192上操作
mysql> stop slave;
Query OK, 0 rows affected (0.00 sec)
mysql> reset master;
ERROR 1186 (HY000): Binlog closed, cannot RESET MASTER
#执行reset master;后报ERROR 1186 (HY000): Binlog closed, cannot RESET MASTER错误
#处理方法
[root@rtb-mysql ~]# vim /etc/my.cnf
[mysqld]
................
................
log-bin=mysql-bin
#重启mysql服务
[root@rtb-mysql ~]# /etc/init.d/mysqld restart
Shutting down MySQL... SUCCESS!
Starting MySQL.. SUCCESS!
#重启激活从库
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> reset master;
Query OK, 0 rows affected (0.01 sec)
mysql> reset slave all;
Query OK, 0 rows affected (0.00 sec)
mysql> show binary logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 120 |
+------------------+-----------+
1 row in set (0.00 sec)
七、将原来主库变为从库
说明：在172.104.29.30操作
mysql> change master to master_host='172.104.29.192',master_port=3306,master_user='rpl',master_password='123456',master_log_file='mysql-bin.000001',master_log_pos=120;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.104.29.192
Master_User: rpl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 120
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 283
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 120
Relay_Log_Space: 457
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 192
Master_UUID: d6a09587-f9ca-11e7-b50b-f23c91cd54d8
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)