cherry-pick #2412 to release-4.0
You can switch your code base to this Pull Request by using git-extras:

# In tics repo:
git pr https://github.com/pingcap/tics/pull/2433

After apply modifications, you can push your change to this PR via:

git push git@github.com:ti-srebot/tics.git pr/2433:release-4.0-114c55c3cb1f

Signed-off-by: JaySon-Huang jayson.hjs@gmail.com

What problem does this PR solve?

Issue Number: close #2413

Problem Summary: When TiFlash is deployed on multi disks, we need to check the file existence among all disks. Or we may generate some PageFiles that share the same PageFileID. While restoring from disks, we may ignore some PageFiles because of inserting them into PageFile "set".

What is changed and how it works?

• Check the file existence among all disks for DataCompactor:: migratePages
• Add mock classes for testing

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch:

Check List

Tests

• Unit test

Side effects

Release note

• Fix the bug that TiFlash can not restore data under some situations when deployed on multi disks