| Bug #99677 | Clone Plugin won't backup empty database | ||
|---|---|---|---|
| Submitted: | 24 May 2020 14:35 | Modified: | 29 Jun 2020 8:40 |
| Reporter: | chen chen (OCA) | Email Updates: | |
| Status: | Not a Bug | Impact on me: | |
| Category: | MySQL Server: Clone Plugin | Severity: | S3 (Non-critical) |
| Version: | 8.0.20 | OS: | Linux |
| Assigned to: | CPU Architecture: | x86 | |
[24 May 2020 14:35]
chen chen
[25 May 2020 12:25]
MySQL Verification Team
Hi Mr. chen, Thank you for your bug report. However, I have to ask you some question. You seem to have specified the already existing directory as a target directory. Can you please, elaborate it. If you have not specified your current datadir, then you have cloned successfully, since that directory is full. Next, I hope that your user has BACKUP_ADMIN privilege. Last, but not least, does user `mysql` has writing rights from /data directory up to and including the final directory. That would be all for the start.
[26 May 2020 22:40]
chen chen
That is easy to reproduce, i start from scratch. [root@node1 ~]# mkdir -p /backup [root@node1 ~]# chown mysql.mysql /backup/ [root@node1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 24G 18G 6.3G 74% / devtmpfs 227M 0 227M 0% /dev tmpfs 237M 0 237M 0% /dev/shm tmpfs 237M 21M 216M 9% /run tmpfs 237M 0 237M 0% /sys/fs/cgroup /dev/sda1 197M 97M 100M 50% /boot tmpfs 48M 0 48M 0% /run/user/0 [root@node1 ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 50 Server version: 8.0.20 MySQL Community Server - GPL Copyright (c) 2000, 2020, 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. mysql> show tables from slowtech; Empty set (0.30 sec) [root@node1 ~]# mysql -uclone_user -pclone_pass mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 49 Server version: 8.0.20 MySQL Community Server - GPL Copyright (c) 2000, 2020, 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. mysql> show grants; +-----------------------------------------------+ | Grants for clone_user@% | +-----------------------------------------------+ | GRANT USAGE ON *.* TO `clone_user`@`%` | | GRANT BACKUP_ADMIN ON *.* TO `clone_user`@`%` | +-----------------------------------------------+ 2 rows in set (0.00 sec) mysql> clone local data directory='/backup/3307'; Query OK, 0 rows affected (12.02 sec) [root@node1 ~]# ll /backup/3307/ total 159748 drwxr-x--- 2 mysql mysql 89 May 27 06:37 #clone -rw-r----- 1 mysql mysql 3646 May 27 06:37 ib_buffer_pool -rw-r----- 1 mysql mysql 12582912 May 27 06:37 ibdata1 -rw-r----- 1 mysql mysql 50331648 May 27 06:37 ib_logfile0 -rw-r----- 1 mysql mysql 50331648 May 27 06:37 ib_logfile1 drwxr-x--- 2 mysql mysql 6 May 27 06:37 mysql -rw-r----- 1 mysql mysql 25165824 May 27 06:37 mysql.ibd drwxr-x--- 2 mysql mysql 28 May 27 06:37 sys -rw-r----- 1 mysql mysql 10485760 May 27 06:37 undo_001 -rw-r----- 1 mysql mysql 14680064 May 27 06:37 undo_002
[27 May 2020 12:37]
MySQL Verification Team
Hi Mr. chen, I have run your test case on my machine and you are correct. Empty databases are not cloned. I do not know whether it is by intention, in which case this would be a documentation bug. Verified as reported.
[29 Jun 2020 8:40]
Erlend Dahl
Posted by developer: [4 Jun 2020 4:36] Debarun Banerjee "CLONE PLUGIN WON'T BACKUP EMPTY DATABASE" - I find problem in the bug heading :) Clone is not a backup tool. The only issue could be if the empty database is not cloned. How to validate it ? Easy, just start mysqld server using the cloned directory and check. mysql> clone local data directory='/data/mysql/3307'; Query OK, 0 rows affected (3.16 sec) "Then i check the backup directory ..." - Let's call it "cloned directory" and let's not try to count files/directories there :) Only person who can read it is the mysqld server. So, let's just start the server with the "cloned directory" and check ... mysqld --datadir= '/data/mysql/3307' mysql -u root mysql> show databases; | information_schema | | mysql | | performance_schema | | slowtech | | sys | Wow! slowtech is there. mysql> use slowtech; Database changed mysql> So, we can only conclude that slowtech is actually cloned. Now Let's look at the data directory... ll /data/mysql/3307 drwxr-x--- 2 mysql mysql 4096 Jun 4 16:44 slowtech/ So the directory also have appeared. What is happening under the hood is apparent by looking at the server log while starting mysqld ... 2020-06-04T11:14:41.828769Z 1 [Note] [MY-011977] [InnoDB] Clone Fixup: check and create schema directory ... 2020-06-04T11:14:41.831196Z 0 [Note] [MY-011977] [InnoDB] Clone: Fixed Schema: slowtech task: 0 So, I think we should agree that there is no real issue here.
[29 Jun 2020 13:07]
MySQL Verification Team
Thank you, Erlend ......
