owner: fix new owner updating checkpoint too early with pending DDL (#2252)

[ti-chi-bot]

This is an automated cherry-pick of #2252

What problem does this PR solve?

• DDL lost after owner is killed (kill_owner_with_ddl fails) #1260 was reintroduced into the new owner (released in v5.1.0)

What is changed and how it works?

• Changed the start-ts of DDL puller to checkpoint - 1, to satisfy the open-interval assumption by TiKV.
• Fetch the snapshot of meta data at checkpoint instead of checkpoint-1 avoid overlap between listened DDL events and fetched schema snapshot.

Check List

Tests

• Unit test
• Integration test

Related changes

• Need to cherry-pick to the release branch

Release note

• Fix potential DDL loss when owner crashes while executing DDL

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has not been approved.

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[amyangfei]

/merge

[amyangfei]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 900718b

[ti-chi-bot]

@ti-chi-bot: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[amyangfei]

/run-kafka-tests