MySQL GTID (三)
五.如何跳过一个GTID
环境见系列一
5.1 创建表,模拟数据
#主机上
create table t_test (id int primary key ,name varchar(10));
insert into t_test values(1,'aa'),(2,'bb'),(3,'cc');
#备机上插入一条,模拟冲突
insert into t_test values(4,'dd');
5.2 模拟冲突
#主机上
insert into t_test values(4,'dd');
#备机上查看复制状态
show slave status \G;
5.3 通过上图,可以定位到冲突的位置,mysqlbinlog查看具体的语句
#主库上mysqlbinlog 查看相关语句
mysqlbinlog --start-position=930 --stop-position=1193 -d test --base64-output=DECODE-ROWS -v /MySQL/my3306/log/binlog/binlog.000018
5.4 基于GTID模式的复制,跳过一个事务,需要利用一个空事务。
stop slave;
set GTID_NEXT='9760cb92-693e-11e8-85bf-000c29b55cf0:11';
#开启一个空事务
begin;commit;
SET GTID_NEXT='AUTOMATIC';
start slave ;
#查看复制是否正常
mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.144
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: binlog.000019
Read_Master_Log_Pos: 194
Relay_Log_File: relaylog.000017
Relay_Log_Pos: 357
Relay_Master_Log_File: binlog.000019
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: 194
Relay_Log_Space: 804
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: 101
Master_UUID: 9760cb92-693e-11e8-85bf-000c29b55cf0
Master_Info_File: /MySQL/my3306/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 9760cb92-693e-11e8-85bf-000c29b55cf0:8-11
Executed_Gtid_Set: 790ff8a6-918a-11e8-87db-000c29c27768:1,
9760cb92-693e-11e8-85bf-000c29b55cf0:1-11
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
六.利用GTID模式快速改变主从复制关系
原架构:主:192.168.2.144
从:192.168.2.138/192.168.2.147
先架构:改为级联模式
基于GTID复制,DBA可以快速调整复制的拓扑结构,只需要调整复制节点的基本信息,不需要手动寻找复制点
6.1 停止192.168.2.147实例的复制
STOP SLAVE;
6.2 调整192.168.2.147实例的复制关系,修改复制源为138,MASTER_AUTO_POSITION为1
CHANGE MASTER TO MASTER_HOST='192.168.2.138',
MASTER_PORT=3306,
MASTER_AUTO_POSITION=1;
6.3 启动192.168.2.147
START SLAVE;
6.4 观察复制的情况
SHOW SLAVE STATUS \G;
6.5 START SLAVE后,节点138 与节点 147的交互如下
1.147节点向138节点发起一个Dump Binlg请求,并将自身已经执行的GTID集合信息一起发送给138节点。
2.138节点通过对比接收到147节点发送过来的GTID集合,将147节点未执行的Binlog信息发送给C节点。
3.147节点获取未执行的Binlog信息,并应用这些Binlog,在这个过程中,138节点还会不断的发送最新的Binlog到147.
4.147节点不断的apply Binlog,最终实现147节点与138节点的同步。
正常来说,到这一步级联复制就建立起来了,但是由于本文之前在192.168.2.138上跳过一个GTID,导致报错
解决方案:
RESET MASTER;
#在 192.168.2.138上 查询Executed_Gtid_Set
show MASTER status \G;
*************************** 1. row ***************************
File: binlog.000007
Position: 1385
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set: 790ff8a6-918a-11e8-87db-000c29c27768:1,
9760cb92-693e-11e8-85bf-000c29b55cf0:1-11
1 row in set (0.00 sec)
#在192.168.2.147跳过这些GTID
SET GLOBAL GTID_PURGED='9760cb92-693e-11e8-85bf-000c29b55cf0:1-11';
START SLAVE;
#此时复制正常
show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.138
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: binlog.000007
Read_Master_Log_Pos: 1385
Relay_Log_File: relaylog.000003
Relay_Log_Pos: 445
Relay_Master_Log_File: binlog.000007
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: 1385
Relay_Log_Space: 1203
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: 102
Master_UUID: 790ff8a6-918a-11e8-87db-000c29c27768
Master_Info_File: /MySQL/my3306/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 790ff8a6-918a-11e8-87db-000c29c27768:1
Executed_Gtid_Set: 9760cb92-693e-11e8-85bf-000c29b55cf0:1-11
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)