[fix](scanner) Fix deadlock when scanner submit failed #40495 #40640
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
We have dead lock when submit scanner to scheduler failed.
pstack looks like
```txt
Thread 2012 (Thread 0x7f87363fb700 (LWP 4179707) "Pipe_normal [wo"):
.h:749
```
Deallock happens with following
```cpp
Status ScannerContext::get_block_from_queue {
std::unique_lock l(_transfer_lock);
...
if (scan_task->is_eos()) {
...
} else {
// resubmit current running scanner to read the next block
submit_scan_task(scan_task);
}
}
ScannerContext::submit_scan_task(std::shared_ptr<ScanTask> scan_task) {
_scanner_scheduler->submit(shared_from_this(), scan_task);
}
void ScannerScheduler::submit(std::shared_ptr<ScannerContext> ctx,
std::shared_ptr<ScanTask> scan_task) {
...
if (auto ret = sumbit_task(); !ret) {
scan_task->set_status(Status::InternalError(
"Failed to submit scanner to scanner pool reason:" + std::string(ret.msg()) +
"|type:" + std::to_string(type)));
ctx->append_block_to_queue(scan_task);
return;
}
}
void ScannerContext::append_block_to_queue(std::shared_ptr<ScanTask> scan_task) {
...
std::lock_guard<std::mutex> l(_transfer_lock);
...
}
```
Since mutex in cpp is not re-enterable, so the scanner thread will
deadlock with itself.
This pr fix the problem by making `ScannerScheduler::submit` return a
Status instead of doing append failed task to the ScannerContext. The
caller itself will decide where resubmit the scanner or just abort the
execution of the query.
|
run buildall |
|
Thank you for your contribution to Apache Doris. Since 2024-03-18, the Document has been moved to doris-website. |
![github-actions[bot]](https://github.com/avatars/in/15368?s=60&v=4){kind=small}
|
TeamCity be ut coverage result: |
yiguolei
approved these changes
Sep 11, 2024
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.
cherry pick from #40495