BACKUP SQL Command returns size of 0

[haiboumich]

Bug Report

1. Minimal reproduce step (Required)

(1) start a TiDB cluster locally through tiup

1. env: CentOS
2. command: tiup playground
3. version: v5.1.1

(2) generate some data before backup

I used the following script to generate around 5 million records

#!/bin/bash

mysql -h127.0.0.1 -P4000 -uroot -e "CREATE TABLE if not exists test.user(name VARCHAR(200), age int) COMMENT='user info';"

for((i=1;i<=10000;i++));  
do   
        mysql -h127.0.0.1 -P4000 -uroot -e "INSERT INTO test.user VALUES('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30), ('AAA', 10), ('BBB', 20), ('CCC', 30);"
done  

(3) use SQL command to backup

BACKUP DATABASE * TO 'local:///tmp/backup0816/full';

2. What did you expect to see? (Required)

After the BACKUP is finished, it should return info about the BACKUP whose size is bigger than 0.

3. What did you see instead (Required)

The backup took 9.04 seconds and the "Size" is 0, while I could see the backup file in folder /tmp/backup0816/full and I could use these files to retore to a new constructed empty TiDB cluster using SQL command RESTORE DATABASE * FROM 'local:///tmp/backup0816/full';

+------------------------------+------+--------------------+---------------------+---------------------+
| Destination                  | Size | BackupTS           | Queue Time          | Execution Time      |
+------------------------------+------+--------------------+---------------------+---------------------+
| local:///tmp/backup0816/full |    0 | 427058788672733186 | 2021-08-16 15:46:33 | 2021-08-16 15:46:33 |
+------------------------------+------+--------------------+---------------------+---------------------+
1 row in set (9.04 sec)

4. What is your TiDB version? (Required)

MySQL [test]> SELECT tidb_version();
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                                       |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v5.1.1
Edition: Community
Git Commit Hash: 797bddd25310ed42f0791c8eccb78be8cce2f502
Git Branch: heads/refs/tags/v5.1.1
UTC Build Time: 2021-07-28 11:00:26
GoVersion: go1.16.4
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

[3pointer]

/assign @fengou1

[YuJuncen]

The root cause of the problem is that we get the total size via a key named "Size" in the summary collector:

tidb/executor/brie.go

Lines 509 to 510 in f7fdffc

	case "Size":
	gs.info.archiveSize = value

...but we recorded the size with other keys, we can record the same data with key "Size" to solve the problem, at, for example, here:

tidb/br/pkg/task/restore.go

Line 269 in 550c7d0

g.Record(summary.RestoreDataSize, archiveSize)

[fengou1]

Test on v5.0.2, it works as expected

[fengou1]

BACKUP in v5.1.1:

RESTORE in v5.1.1:

[fengou1]

#27508

[ti-srebot]

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