Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. Create a table with tiflash replica
2. Load data into the table until it contains thousands of Regions in the raft level, and thousands of Segments in the DeltaTree storage engine level
3. Drop the table

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

The dropped table gets dropped smoothly, without affecting TiFlash's raft-log syncing and causing failed queries

3. What did you see instead (Required)

The raft-log syncing is blocked for tens of minutes, and coming raft messages make tiflash OOM.
And raft-log syncing is blocked also makes failed queries because the learner read timeout by waiting raft-log syncing index.

4. What is your TiFlash version? (Required)

v7.1.3