Fix flaky EventListenerTest.DisableBGCompaction #9400
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Summary: Wasn't able to easily reproduce error, but easy to see a race condition between TestFlushListener::OnFlushCompleted and DBTestBase::Close(), which frees CF handles before closing DB. Test Plan: CI etc.
|
@pdillinger has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
riversand963
approved these changes
Jan 19, 2022
db/listener_test.cc
Outdated
| @@ -515,6 +515,9 @@ TEST_F(EventListenerTest, DisableBGCompaction) { | |||
| db_->GetColumnFamilyMetaData(handles_[1], &cf_meta); | |||
| } | |||
| ASSERT_GE(listener->slowdown_count, kSlowdownTrigger * 9); | |||
| // We don't want the listener executing during DBTestBase::Close() due to | |||
| // race on handles_. | |||
| dbfull()->TEST_WaitForBackgroundWork(); | |||
There was a problem hiding this comment.
How about also asserting on error_handler_.GetBGError() is OK?
There was a problem hiding this comment.
Better, I'll make TEST_WaitForBackgroundWork() return error_handler_.GetBGError() (like other similar functions) and ASSERT_OK on that.
|
@pdillinger has updated the pull request. You must reimport the pull request before landing. |
|
@pdillinger has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
facebook-github-bot
pushed a commit
that referenced
this pull request
Feb 22, 2022
Summary: We often see flaky tests due to `DB::Flush()` or `DBImpl::TEST_WaitForFlushMemTable()` not waiting until event listeners complete. For example, #9084, #9400, #9528, plus two new ones this week: "EventListenerTest.OnSingleDBFlushTest" and "DBFlushTest.FireOnFlushCompletedAfterCommittedResult". I ran a `make check` with the below race condition-coercing patch and fixed issues it found besides old BlobDB. ``` diff --git a/db/db_impl/db_impl_compaction_flush.cc b/db/db_impl/db_impl_compaction_flush.cc index 0e1864788..aaba68c4a 100644 --- a/db/db_impl/db_impl_compaction_flush.cc +++ b/db/db_impl/db_impl_compaction_flush.cc @@ -861,6 +861,8 @@ void DBImpl::NotifyOnFlushCompleted( mutable_cf_options.level0_stop_writes_trigger); // release lock while notifying events mutex_.Unlock(); + bg_cv_.SignalAll(); + sleep(1); { for (auto& info : *flush_jobs_info) { info->triggered_writes_slowdown = triggered_writes_slowdown; ``` The reason I did not fix old BlobDB issues is because it appears to have a fundamental (non-test) issue. In particular, it uses an EventListener to keep track of the files. OnFlushCompleted() could be delayed until even after a compaction involving that flushed file completes, causing the compaction to unexpectedly delete an untracked file. Pull Request resolved: #9617 Test Plan: `make check` including the race condition coercing patch Reviewed By: hx235 Differential Revision: D34384022 Pulled By: ajkr fbshipit-source-id: 2652ded39b415277c5d6a628414345223930514e
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary: Wasn't able to easily reproduce error, but easy to see a race
condition between TestFlushListener::OnFlushCompleted and
DBTestBase::Close(), which frees CF handles before closing DB.
Test Plan: CI etc.