Fix large write cause tiflash crash (release-6.5) (#7345)

[ti-chi-bot]

This is an automated cherry-pick of #7345

Manual cherry-pick of #7335

---

What problem does this PR solve?

Issue Number: close #7316

Problem Summary:

The root cause is BlobStore<Trait>::handleLargeWrite get a buffer from MemoryWriteBuffer and access the memory by write.size, which exceed the memory bound. MemoryWriteBuffer actually is composed by a list of chunks

tiflash/dbms/src/Storages/Page/V3/BlobStore.cpp

Lines 190 to 216 in b2b976e

	BufferBase::Buffer data_buf = write.read_buffer->buffer();
	digest.update(data_buf.begin(), write.size);
	entry.checksum = digest.checksum();
	UInt64 field_begin, field_end;
	for (size_t i = 0; i < write.offsets.size(); ++i)
	{
	ChecksumClass field_digest;
	field_begin = write.offsets[i].first;
	field_end = (i == write.offsets.size() - 1) ? write.size : write.offsets[i + 1].first;
	field_digest.update(data_buf.begin() + field_begin, field_end - field_begin);
	write.offsets[i].second = field_digest.checksum();
	}
	if (!write.offsets.empty())
	{
	// we can swap from WriteBatch instead of copying
	entry.field_offsets.swap(write.offsets);
	}
	try
	{
	auto blob_file = getBlobFile(blob_id);
	blob_file->write(data_buf.begin(), offset_in_file, write.size, write_limiter);

What is changed and how it works?

The write batch data size is large, we do NOT copy the data into a temporary buffer in order to make the memory usage of tiflash more smooth. Instead, we process the data in ReadBuffer in a streaming manner.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Fix a crash issue when tiflash persists the data of a large Region

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• Lloyd-Pottiger
• hongyunyan

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.

[JaySon-Huang]

/merge

[ti-chi-bot]

@JaySon-Huang: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and 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.

If you have any questions about the PR merge process, please refer to pr process.

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.

[ti-chi-bot]

@JaySon-Huang: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

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.

[Lloyd-Pottiger]

/merge

[ti-chi-bot]

@Lloyd-Pottiger: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and 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.

If you have any questions about the PR merge process, please refer to pr process.

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.

[ti-chi-bot]

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

Commit hash: e77ac18

[JaySon-Huang]

/run-integration-test branch=release-6.5

[JaySon-Huang]

/run-integration-test tidb=release-6.5 tikv=release-6.5 pd=release-6.5

[JaySon-Huang]

/run-integration-test tidb=release-6.5