Compatible test: BR restore failed due to checksum mismatch.

[3pointer]

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.
   Try to use BR (nightly) to restore (v4.0.11) backups. First found in Compatibility test: create github actions for test #708.

simplify to reproduce.

1. tiup playground v4.0.11 --tiflash 0

2. connect to v4.0.11 tidb via mysql client
   a. create table test.t(id int);
   b. insert into test.t values (1);
   c. insert into test.t values (3);
   d. backup database test to 'local:///tmp/bktest01';

3. tiup playground nightly --tiflash 0

4. connect to nightly tidb via mysql client
   a. restore database * from 'local:///tmp/bktest01';

5. What did you expect to see?

restore successd.

3. What did you see instead?

[restore.go:34] ["failed to restore"] [error="failed to validate checksum: [BR:Restore:ErrRestoreChecksumMismatch]restore checksum mismatch"] [errorVerbose="[BR:Restore:ErrRestoreChecksumMismatch]restore checksum mismatch\nfailed to validate checksum\ngithub.com/pingcap/br/pkg/restore.(*Client).execChecksum\n\tgithub.com/pingcap/br@/pkg/restore/client.go:817\ngithub.com/pingcap/br/pkg/restore.(*Client).GoValidateChecksum.func1.2\n\tgithub.com/pingcap/br@/pkg/restore/client.go:757\ngithub.com/pingcap/br/pkg/utils.(*WorkerPool).ApplyOnErrorGroup.func1\n\tgithub.com/pingcap/br@/pkg/utils/worker.go:63\ngolang.org/x/sync/errgroup.(*Group).Go.func1\n\tgolang.org/x/sync@v0.0.0-20201020160332-67f06af15bc9/errgroup/errgroup.go:57\nruntime.goexit\n\truntime/asm_amd64.s:1357"] [stack="main.runRestoreCommand\n\tgithub.com/pingcap/br@/cmd/br/restore.go:34\nmain.newDBRestoreCommand.func1\n\tgithub.com/pingcap/br@/cmd/br/restore.go:131\ngithub.com/spf13/cobra.(*Command).execute\n\tgithub.com/spf13/cobra@v1.0.0/command.go:842\ngithub.com/spf13/cobra.(*Command).ExecuteC\n\tgithub.com/spf13/cobra@v1.0.0/command.go:950\ngithub.com/spf13/cobra.(*Command).Execute\n\tgithub.com/spf13/cobra@v1.0.0/command.go:887\nmain.main\n\tgithub.com/pingcap/br@/cmd/br/main.go:56\nruntime.main\n\truntime/proc.go:203"]

4. What version of BR and TiDB/TiKV/PD are you using?

5. Operation logs

   • Please upload br.log for BR if possible
   • Please upload tidb-lightning.log for TiDB-Lightning if possible
   • Please upload tikv-importer.log from TiKV-Importer if possible
   • Other interesting logs

6. Configuration of the cluster and the task

   • tidb-lightning.toml for TiDB-Lightning if possible
   • tikv-importer.toml for TiKV-Importer if possible
   • topology.yml if deployed by TiUP

7. Screenshot/exported-PDF of Grafana dashboard or metrics' graph in Prometheus if possible

[3pointer]

The reason is table already has data before restoration. so we need to check whether the table has data before restoration. I'll file an issue later.