KVStore: Fix exception in FAP worker

[CalvinNeo]

What problem does this PR solve?

Issue Number: close #8988

Problem Summary:

What is changed and how it works?

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

None

[CalvinNeo]

/cc @JaySon-Huang @Lloyd-Pottiger @JinheLin

[purelind]

/check-issue-triage-complete

[JaySon-Huang]

Seems this test does not go through the logic of prev_state == FAPAsyncTasks::TaskState::Finished?

tiflash/dbms/src/Storages/KVStore/MultiRaft/Disagg/FastAddPeerContext.cpp

Lines 247 to 270 in 4bfa40d

	RUNTIME_CHECK_MSG(
	prev_state != FAPAsyncTasks::TaskState::Running && prev_state != FAPAsyncTasks::TaskState::InQueue,
	"FastAddPeer: find scheduled fap task, region_id={} fap_state={} is_regular_snapshot={}",
	region_id,
	magic_enum::enum_name(prev_state),
	is_regular_snapshot);
	if (prev_state == FAPAsyncTasks::TaskState::Finished)
	{
	bool is_exception = false;
	try
	{
	tasks_trace->fetchResult(region_id);
	}
	catch (...)
	{
	is_exception = true;
	}
	LOG_INFO(
	log,
	"FastAddPeer: clean finished result region_id={} is_regular_snapshot={} is_exception={}",
	region_id,
	is_regular_snapshot,
	is_exception);
	}

[CalvinNeo]

Yes you are right, actually the code can't pass ut.... fixed.

[JaySon-Huang]

/run-all-tests

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JaySon-Huang, Lloyd-Pottiger

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-04-25 14:27:58.655878491 +0000 UTC m=+270435.395781399: ☑️ agreed by Lloyd-Pottiger.
• 2024-04-25 15:32:12.859965418 +0000 UTC m=+274289.599868329: ☑️ agreed by JaySon-Huang.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #8992.