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一. 基本环境
主库 1: 10.24.65.30 3306 MySQL 5.7.14
主库 2: 10.24.65.30 3307 mysql 5.7.14
从库：10.24.65.33 3306 mysql 5.7.14
基于 gtid 的多源复制。
二.gtid-mode 的几种状态说明：
off : 不产生 gtid，基于 binlog+position，slave 也不能接受 gtid 的日志;
off_permissive: 不产生 gtid，但做为 slave 可以识别 gtid 事务也可以识别非 gtid 事务;
on_permissive: 产生 gtid 事务，slave 可以处理 gtid 事务和非 gtid 事务;
on: 产生 gtid 事务，slave 只接受 gtid 事务。
三. 在线切换
1. 停掉 channel ‘master-65303306’ 的复制, 禁止:master_auto_position
先停掉 master-65303306 的 slave，并记录下 master_log_file 和 position 信息。
stop slave for channel ‘master-65303306’;
(product)root@localhost [test]> show slave status for channel ‘master-65303306’\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 10.24.65.30
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000435
Read_Master_Log_Pos: 234
Relay_Log_File: relay-bin-master@002d65303306.000507
Relay_Log_Pos: 447
Relay_Master_Log_File: mysql-bin.000435
Slave_IO_Running: No
Slave_SQL_Running: No
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: 234
Relay_Log_Space: 1835
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: 65303306
Master_UUID: 58abaa9b-73dd-11e6-9690-0050568a704b
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name: master-65303306
Master_TLS_Version:
1 row in set (0.00 sec)
根据以上信息编写 change master:
change master to master_auto_position=0,master_log_file=’mysql-bin.000435′,\
master_log_pos=’234′ for channel ‘master-65303306’;
start slave for channel ‘master-65303306’;
2. 停掉 channel ‘master-65303307’ 的复制, 禁止:master_auto_position
先停掉 master-65303307 的 slave，并记录下 master_log_file 和 position 信息。
stop slave for channel ‘master-65303307’;
(product)root@localhost [test]> show slave status for channel ‘master-65303307’\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 10.24.65.30
Master_User: repl
Master_Port: 3307
Connect_Retry: 60
Master_Log_File: mysql-bin.000184
Read_Master_Log_Pos: 475
Relay_Log_File: relay-bin-master@002d65303307.000003
Relay_Log_Pos: 454
Relay_Master_Log_File: mysql-bin.000184
Slave_IO_Running: No
Slave_SQL_Running: No
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: 475
Relay_Log_Space: 1209
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: 65303307
Master_UUID: ebdca3fd-6eb7-11e6-b20c-0050568a704c
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name: master-65303307
Master_TLS_Version:
1 row in set (0.00 sec)
根据以上信息编写 change master:
change master to master_auto_position=0,master_log_file=’mysql-bin.000184′,\
master_log_pos=’475′ for channel ‘master-65303307’;
start slave for channel ‘master-65303307’;
3. 执行 change master
change master to master_auto_position=0,master_log_file=’mysql-bin.000435′,\
master_log_pos=234 for channel ‘master-65303306’;
start slave for channel ‘master-65303306’;
change master to master_auto_position=0,master_log_file=’mysql-bin.000184′,\
master_log_pos=475 for channel ‘master-65303307’;
start slave for channel ‘master-65303307’;
4. 更改日志格式(所有 server)
set @@global.gtid_mode=on_permissive;
(product)root@localhost [test]> show variables like ‘gtid_mode’;
+—————+—————+
| Variable_name | Value |
+—————+—————+
| gtid_mode | ON_PERMISSIVE |
+—————+—————+
1 row in set (0.01 sec)
set @@global.gtid_mode=off_permissive;
(product)root@localhost [(none)]> show variables like ‘gtid_mode’;
+—————+—————-+
| Variable_name | Value |
+—————+—————-+
| gtid_mode | OFF_PERMISSIVE |
+—————+—————-+
1 row in set (0.01 sec)
set @@global.gtid_mode=off;
(product)root@localhost [test]> show variables like ‘gtid_mode’;
+—————+——-+
| Variable_name | Value |
+—————+——-+
| gtid_mode | OFF |
+—————+——-+
1 row in set (0.01 sec)
5. 验证更改
master1 执行：
(product)root@localhost [mdb1]> insert into mdb1.t1 select 1;
查看 slave channel ‘master-65303306’ 的变化 :
插入数据前：
Relay_Master_Log_File: mysql-bin.000438
Exec_Master_Log_Pos: 234
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
插入数据后：
Relay_Master_Log_File: mysql-bin.000438
Exec_Master_Log_Pos: 539
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
master2 执行：
(product)root@localhost [mdb2]> insert into mdb2.t2 select 1;
插入数据前：
Relay_Master_Log_File: mysql-bin.000187
Exec_Master_Log_Pos: 194
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
插入数据后：
Relay_Master_Log_File: mysql-bin.000187
Exec_Master_Log_Pos: 499
Executed_Gtid_Set: 58abaa9b-73dd-11e6-9690-0050568a704b:1-16,
ebdca3fd-6eb7-11e6-b20c-0050568a704b:1-32459,
ebdca3fd-6eb7-11e6-b20c-0050568a704c:1-2
上面的 GTID 没有变化，只有 pos 位点有变化，说明已转换成传统复制生效。
6. 更改配置文件
最后记得要更改 my.cnf 文件中的配置。
gtid-mod=off
enforce-gtid-consistency=off
本文永久更新链接地址：http://www.linuxidc.com/Linux/2016-12/138171.htm
