在使用xtrabackup备份和恢复中遇到的版本问题

昨天接到一个客户关于使用xtrabackup备份和恢复的问题。

在恢复数据之后，启动数据库，得到了如下错误：

[root@mydb01 backup]# cat error.bak
mysqld: Can't open file: 'mysql.ibd' (errno: 0 - )
2023-06-28T10:57:00.337276Z 0 [System] [MY-010116] [Server] /mysql/app/mysql/bin/mysqld (mysqld 8.0.16) starting as process 24546
2023-06-28T10:57:02.960302Z 1 [ERROR] [MY-013171] [InnoDB] Cannot boot server version 80016 on data directory built by version 80018. Downgrade is not supported
2023-06-28T10:57:08.096863Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2023-06-28T10:57:08.097049Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2023-06-28T10:57:08.097205Z 0 [ERROR] [MY-010119] [Server] Aborting
2023-06-28T10:57:08.098353Z 0 [System] [MY-010910] [Server] /mysql/app/mysql/bin/mysqld: Shutdown complete (mysqld 8.0.16)  MySQL Community Server - GPL.
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这里我们很明显可以看到错误信息

2023-06-28T10:57:02.960302Z 1 [ERROR] [MY-013171] [InnoDB] Cannot boot server version 80016 on data directory built by version 80018. Downgrade is not supported
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于是检查了备份和恢复过程中的mysql以及xtrabackup版本，发现是不一致的。

生产数据库的版本是8.0.18.

测试数据库的版本是8.0.16.

从而导致了上述问题.

解决问题的方案非常简单，升级测试数据库到8.0.18，数据库成功启动.

PS:关于xtrabackup备份恢复，推荐的方案是备份和恢复的mysql以及xtrabackup的版本一定要一致。否则会导致数据库无法启动。

日志中会出现版本问题或者undo带来的问题。

附undo问题日志：

2023-06-28T04:47:08.5541747 1 [ERROR] [MV-011971] [InnoDB] Tablespace 'innodb_undo_002! Page Tpage id: space-A29496727e, page number=273]1
sequence number 3202578976495 is in the future! Current system log sequence number 19463180.
2023-06-28T04;47:08-554181Z 1 LERROR] [WV-011972] [Inno0B] Your database may be corrupt or you may have copied the Inno0s tablespace but no he Inno0B log files. Please refer to http://dev.mysql.com/doc/refman/8.0/en/forcing-innodb-recovery.html_for infornation about forcing recovery.
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