br: restore failed when cluster run million table workload with log backup

[AkiraXie]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. open log backup task
2. run million table workload
3. restore to cluster

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

no error

3. What did you see instead (Required)

Detail BR log in /tmp/br.log.2025-03-23T16.32.52Z [2025/03/23 16:34:40.293 +00:00] [INFO] [collector.go:77] ["Full Restore failed summary"] [total-ranges=0] [ranges-succeed=0] [ranges-failed=0] Error: rpc error: code = Unavailable desc = keepalive watchdog timeout

cluster tikv cpu is not so busy

4. What is your TiDB version? (Required)

v9.0

[AkiraXie]

/component br /severity major

[Leavrth]

will be fixed by https://github.com/tikv/tikv/pull/18542

[apollodafoni]

/assign @Leavrth