上一篇文章中已经结合官方文档，说明了如何将RDS-Mysql物理备份恢复到本地，这篇文章是关于如何搭建和RDS—Mysql主从配置的步骤。本篇文章以5.7为例。
但是有一些需要注意的地方：
- 使用这个方法搭建的主从环境，容易受到一些因素的影响，比方本地网络或者RDS本身出现的一些问题（binlog被删除），那么主从的搭建可能会中断。
- 所以如果想要搭建比较稳定的环境，在阿里云上可以参考使用DTS进行配置。
前提条件：
本地已经将RDS的物理文件进行了成功恢复。参考：https://yq.aliyun.com/articles/692056?spm=a2c4e.11155435.0.0.608333123an7eS
第一步
关于本地mysql的cnf文件内容，可以参考下面的格式：
#innodb_checksum_algorithm=crc32
#innodb_log_checksum_algorithm=strict_crc32
innodb_data_file_path=ibdata1:200M:autoextend
innodb_log_files_in_group=2
innodb_log_file_size=1048576000
#innodb_fast_checksum=false
#innodb_page_size=16384
#innodb_log_block_size=512
#innodb_undo_directory=./
#innodb_undo_tablespaces=0
server_id=197
#redo_log_version=1
#server_uuid=e4323bd1-072f-11e9-97a1-7cd30ad32d28
#master_key_id=0
binlog_format=ROW
master-info-repository=file
relay-log-info-repository=file
gtid_mode=on
enforce-gtid-consistency=true
#skip-grant-tables第二步
打开备份解压文件可以看到文件xtrabackup_slave_info，其中第一行就是需要在本地MySQL执行的命令，它表示在备份结束时刻RDS当前GTID值’
下面执行的命令，请参考：
mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed, 1 warning
mysql> truncate table slave_relay_log_info;
Query OK, 0 rows affected (0.02 sec)
mysql> truncate table mysql.slave_master_info;
Query OK, 0 rows affected (0.01 sec)
mysql> truncate table mysql.slave_worker_info;
Query OK, 0 rows affected (0.00 sec)
mysql> reset slave;
Query OK, 0 rows affected (0.01 sec)
mysql> reset master;
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL gtid_purged='6032a4a0-f50e-11e8-b374-7cd30a5a30b4:1-260056, 97e5b5fb-367d-11e9-af9e-7cd30aeb45ba:1-54309, bfe3ada0-1f7a-11e9-acd2-58605f589df3:1-161356, cf84fc60-072f-11e9-b0f9-7cd30ab8f5b0:1-310126, e4323bd1-072f-11e9-97a1-7cd30ad32d28:1-219582';
Query OK, 0 rows affected (0.01 sec)
mysql> change master to master_host='rm-2zeu5m7c190y65ppxx.mysql.rds.aliyuncs.com',master_user='ali',master_port=3306,master_password='xxx',master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.02 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)第三步
进行验证：
然后执行 show slave status 就能够看到下面的结果了。 Slave_IO_Running: Yes Slave_SQL_Running: Yes
然后 Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates 说明主从现在的数据是一致的了。
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: rm-2zeu5m7c190y65ppglo.mysql.rds.aliyuncs.com
Master_User: ali
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000033
Read_Master_Log_Pos: 192183
Relay_Log_File: jun-relay-bin.000002
Relay_Log_Pos: 108422
Relay_Master_Log_File: mysql-bin.000033
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: 192183
Relay_Log_Space: 108627
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: 1441442229
Master_UUID: 97e5b5fb-367d-11e9-af9e-7cd30aeb45ba
Master_Info_File: /home/mysql/aliyun-mysql57/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: 97e5b5fb-367d-11e9-af9e-7cd30aeb45ba:54310-54677
Executed_Gtid_Set: 6032a4a0-f50e-11e8-b374-7cd30a5a30b4:1-260056,
97e5b5fb-367d-11e9-af9e-7cd30aeb45ba:1-54677,
bfe3ada0-1f7a-11e9-acd2-58605f589df3:1-161356,
cf84fc60-072f-11e9-b0f9-7cd30ab8f5b0:1-310126,
e4323bd1-072f-11e9-97a1-7cd30ad32d28:1-219582
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
mysql>在rds上创建新表，插入数据。
查看本地数据：
