一篇搞懂MySQL 8.0 Clone技术在线搭建主从复制全过程

墨墨导读：MySQL从8.0.17开始新增了克隆Clone技术，可以在线进行MySQL的本地克隆或远程克隆，从此搭建从库可以不再需要备份工具来实现了，本文分享Clone技术在线搭建主从复制全过程，希望对大家有帮助。

本文将通过Clone来实现一个远程从库的搭建：环境如下

Mater: 192.168.3.133 port:3307 doner 捐赠者 Slave: 192.168.3.134 port:3307 recipient 接受者

第一步：两台机器MySQL分别进行初始化安装

进入MySQL软件目录进行初始化安装并修改密码：（MySQL8.0.19 下载解压步骤省略）

[root@mgr2 bin]#cd /zcloud/db/abcMgr/abcMgr02/mysql/bin
[root@mgr2 bin]# ./mysqld --initialize --user=mysql
[root@mgr2 bin]# ./mysqld_safe --user=mysql &
[1] 19556
[root@mgr2 bin]# 2020-03-12T01:32:26.503048Z mysqld_safe Logging to ‘/rock/mysqldata/error.log’.
2020-03-12T01:32:26.536292Z mysqld_safe Starting mysqld daemon with databases from /rock/mysqldata
[root@mgr2 bin]#
[root@mgr2 bin]# mysql -uroot -p -P3307
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.19
Copyright © 2000, 2019, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
root@localhost:(none) 09:33:06 >alter user user() identified by ‘root1234’;
Query OK, 0 rows affected (0.00 sec)
root@localhost:(none) 09:33:26 >flush privileges;
Query OK, 0 rows affected (0.00 sec)
root@localhost:(none) 09:33:31 >exit
Bye

第二步：doner节点192.168.3.133相关操作

–创建用户

root@localhost:(none) 10:07:05 >create user ‘donor_user’@‘192.168.3.134’ identified by ‘password’;
Query OK, 0 rows affected (0.00 sec)
root@localhost:(none) 10:07:07 >grant backup_admin on . to ‘donor_user’@‘192.168.3.134’;
Query OK, 0 rows affected (0.01 sec)

–安装clone插件

root@localhost:(none) 10:23:16 >install plugin clone soname ‘mysql_clone.so’;
Query OK, 0 rows affected (0.01 sec)

第三步：recipient节点192.168.3.134相关操作

–创建用户（也可以不创建用户，用root直接操作）

mysql> create user ‘recipient_user’@‘192.168.3.134’ identified by ‘password’;

–安装clone插件

mysql> grant clone_admin on . to ‘recipient_user’@‘192.168.3.134’;

–设置参数clone_valid_donor_list

root@localhost:(none) 03:28:40 >set global clone_valid_donor_list=‘192.168.3.133:3307’;
Query OK, 0 rows affected (0.00 sec)

–换成recipient_user’@‘192.168.3.134’ 用户登陆，执行clone语句(这里其实可以用本地root用户直接进行登录操作)

[root@mgr3 bin]# mysql -urecipient_user -ppassword -P3307 -h192.168.3.134

recipient_user@192.168.3.134:(none) 03:39:46 >clone instance from ‘donor_user’@‘192.168.3.133’:3307 identified by ‘password’;
Query OK, 0 rows affected (2.34 sec)
recipient_user@192.168.3.134:(none) 03:39:57 >Restarting mysqld…
2020-03-12T07:40:01.285267Z mysqld_safe Number of processes running now: 0
2020-03-12T07:40:01.290169Z mysqld_safe mysqld restarted

至此，远程数据的克隆已经完成了。

通过查询两张表来监控一下克隆的进度和结果状态：

–查看clone进度和状态

root@localhost:(none) 03:34:49 >SELECT * FROM performance_schema.clone_progress;
±-----±----------±----------±---------------------------±---------------------------±--------±----------±----------±----------±-----------±--------------+
| ID | STAGE | STATE | BEGIN_TIME | END_TIME | THREADS | ESTIMATE | DATA | NETWORK | DATA_SPEED | NETWORK_SPEED |
±-----±----------±----------±---------------------------±---------------------------±--------±----------±----------±----------±-----------±--------------+
| 1 | DROP DATA | Completed | 2020-03-12 15:29:15.385694 | 2020-03-12 15:29:15.634609 | 1 | 0 | 0 | 0 | 0 | 0 |
| 1 | FILE COPY | Completed | 2020-03-12 15:29:15.634765 | 2020-03-12 15:29:17.452961 | 1 | 465800520 | 465800520 | 465833356 | 0 | 0 |
| 1 | PAGE COPY | Completed | 2020-03-12 15:29:17.453144 | 2020-03-12 15:29:17.554224 | 1 | 0 | 0 | 99 | 0 | 0 |
| 1 | REDO COPY | Completed | 2020-03-12 15:29:17.554413 | 2020-03-12 15:29:17.654430 | 1 | 2560 | 2560 | 3031 | 0 | 0 |
| 1 | FILE SYNC | Completed | 2020-03-12 15:29:17.654596 | 2020-03-12 15:29:17.730172 | 1 | 0 | 0 | 0 | 0 | 0 |
| 1 | RESTART | Completed | 2020-03-12 15:29:17.730172 | 2020-03-12 15:29:22.160372 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | RECOVERY | Completed | 2020-03-12 15:29:22.160372 | 2020-03-12 15:29:22.478889 | 0 | 0 | 0 | 0 | 0 | 0 |
±-----±----------±----------±---------------------------±---------------------------±--------±----------±----------±----------±-----------±--------------+
7 rows in set (0.00 sec)
root@localhost:(none) 03:34:52 >SELECT * FROM performance_schema.clone_status\G
*************************** 1. row ***************************
ID: 1
PID: 0
STATE: Completed
BEGIN_TIME: 2020-03-12 15:29:15.385
END_TIME: 2020-03-12 15:29:22.479
SOURCE: 192.168.3.133:3307
DESTINATION: LOCAL INSTANCE
ERROR_NO: 0
ERROR_MESSAGE:
BINLOG_FILE: mysql-bin.000002
BINLOG_POSITION: 421
GTID_EXECUTED: 3e75bf2f-6401-11ea-8995-000c29db65a6:1
1 row in set (0.00 sec)

–在主库133上建立复制账号：

root@localhost:(none) 04:12:23 >create user repl@‘192.168.3.%’ identified by ‘repl’;
Query OK, 0 rows affected (0.00 sec)
root@localhost:(none) 04:13:03 >grant all on . to repl@‘192.168.3.%’;
Query OK, 0 rows affected (0.00 sec)

–在从库134上进行复制步骤的完成：

root@localhost:(none) 04:16:09 >change master to master_host=‘192.168.3.133’,master_port=3307,master_user=‘repl’,master_password=‘repl’,master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.00 sec)
root@localhost:(none) 04:17:32 >start slave;
Query OK, 0 rows affected (0.00 sec)
root@localhost:(none) 04:17:35 >show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.3.133
Master_User: repl
Master_Port: 3307
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 1193
Relay_Log_File: mgr3-relay-bin.000002
Relay_Log_Pos: 904
Relay_Master_Log_File: mysql-bin.000002
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: 1193
Relay_Log_Space: 1103
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: 207
Master_UUID: 3e75bf2f-6401-11ea-8995-000c29db65a6
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: 3e75bf2f-6401-11ea-8995-000c29db65a6:3-4
Executed_Gtid_Set: 3e75bf2f-6401-11ea-8995-000c29db65a6:1-4
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set (0.00 sec)

至此远程从库通过clone插件的方式搭建成功了，非常简单也非常快速，不需要mysqldump也不需要xtrabackup，在线搭建成功，非常快，以后用8.0可以考虑这种便捷的方式了。

最后将clone技术的 限制条件 列出：

1. 版本大于等于8.0.17且不支持跨版本
2. 两台机器具有相同的操作系统OS
3. 两台MySQL实例具体相同的 innodb_page_size 和 innodb_data_file_path(ibdata文件名)
4. 同一时刻仅仅允许有一个克隆任务存在
5. recipient 需要设置变量clone_valid_donor_list
6. max_allowed_packet 大于2M
7. doner的undo表空间文件名称不能重复
8. 不会克隆my.cnf文件
9. 不会克隆binlog
10. 仅仅支持innodb引擎

墨天轮原文链接：https://www.modb.pro/db/22511