多源复制的意义
1.可以在一个从库上对多个服务器的数据库进行汇总，或者对一个数据库的分库分表进行汇总。
2.集约使用从库服务器的硬件资源，毕竟弱一个数据库业务量较小确占用整个服务器资源是不经济的。
3.更方便的对个业务库进行数据备份，优化数据库备份脚本编写逻辑
拓补图
实施步骤
1.备份主库上的数据，考虑到gtid的问题建议只采用mysqldump程序进行备份
centos:#mysqldump --login-path=3306 \ #mysql官方工具都支持login-path快速登录 --single-transaction \ #事务一致性备份，防止备份完整性被事务一致性破坏 --master-data=2 \ #在备份文件的头部加一句change master to pos的注释语句 -A >ip06p3306.sql #备份所有数据库
2.将导出的文件传输到从库的服务器上
centos_ip06:#scp ip06p3306.sql root@192.168.1.11:/root/ centos_ip31:#scp ip31p3306.sql root@192.168.1.11:/root/
3.将主库的备份文件导入到从库上
centos:#mysql --login-path=3306 -f <ip06p3306.sql #-f参数，忽略应用备份时产生的GTID冲突
4.从两份备份文件的头部查看两个主库备份时执行到的GTID
centos:#less ip06p3306.sql|grep PURGED #得到GTID_ip06 centos:#less ip31p3306.sql|grep PURGED #得到GTID_ip31
5.重新设置从库的GTID（在从库上执行）
mysql>reset master； mysql>set global gtid_purged=‘GTID_ip06,GTID_ip31‘;
6.将从库的指向各自的主库
mysql>change master to \ master_host=‘192.168.1.6‘,master_port=3306, master_user=‘repl‘,master_password=‘123456‘, \ master_auto_postion=1 \自动对齐GTID，从库宕机重启后，删除未执行relaylog，重新拉取 for channel ‘master_3306‘;为这个主设定一个频道名，可设为易于辨认的名字
7.设置不方便同步的库：（如会导致复制出重复用户的mysql库）
但sys,performance,information为模式或者视图一样的存在，数据在读取时即时生成，不真正存储数据，可以不过滤
mysql>stop slave sql_thread;#停止从库的重放进程，比停止整个从库要方便的多 mysql>change replication filter replicate_ignore_db=(mysql,db1);\#把复制的库放在括号里，并用,分隔 mysql>start slave sql_thread；
8.查看信息：
mysql> show slave status\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.6 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000016 Read_Master_Log_Pos: 194 Relay_Log_File: localhost-relay-bin-master_3306.000033 Relay_Log_Pos: 367 Relay_Master_Log_File: mysql-bin.000016 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: 803 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: 13306 Master_UUID: 449fdd93-1b80-11e7-b054-000c29aa1d65 Master_Info_File: mysql.slave_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: Executed_Gtid_Set: 066c3194-2b4b-11e7-b67b-000c290b6ef0:1-2951823, 449fdd93-1b80-11e7-b054-000c29aa1d65:1-140, efa1d12e-3c56-11e7-a99e-000c29ba498d:1-481 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: master_3306 Master_TLS_Version: *************************** 2. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.31 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000026 Read_Master_Log_Pos: 375018221 Relay_Log_File: localhost-relay-bin-master_zabbix.000032 Relay_Log_Pos: 375018394 Relay_Master_Log_File: mysql-bin.000026 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: 375018221 Relay_Log_Space: 375018619 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 n 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: 313306 Master_UUID: 066c3194-2b4b-11e7-b67b-000c290b6ef0 Master_Info_File: mysql.slave_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: 066c3194-2b4b-11e7-b67b-000c290b6ef0:2310554-2951823 Executed_Gtid_Set: 066c3194-2b4b-11e7-b67b-000c290b6ef0:1-2951823, 449fdd93-1b80-11e7-b054-000c29aa1d65:1-140, efa1d12e-3c56-11e7-a99e-000c29ba498d:1-481 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: master_zabbix Master_TLS_Version: 2 rows in set (0.01 sec)
本文出自 “漫漫SQL路......” 博客，请务必保留此出处http://l0vesql.blog.51cto.com/4159433/1933651
原文地址：http://l0vesql.blog.51cto.com/4159433/1933651
