Bug #96192 Possible race condition with binlog-transaction-dependency-tracking
Submitted: 12 Jul 2019 16:09 Modified: 24 Oct 2019 22:39
Reporter: Herman Lee Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:8.0.16 OS:Any
Assigned to: CPU Architecture:Any

[12 Jul 2019 16:09] Herman Lee 
Description:
In looking the patch for "Bug#28511326: DEADLOCK DURING PURGE_LOGS_BEFORE_DATE" which was meant to fix the deadlock introduced by the binlog-transaction-dependency-tracking variable acquiring the mysql_bin_log.LOCK_log mutex, we believe there are other locations that need to also acquire the new lock.

m_dependency_tracking.rotate() which clears the writeset is called during open_binlog() with the LOCK_log held. Updating the binlog-transaction-dependency-tracking also clears the writeset, but is not longer holding the LOCK_log.

How to repeat:
Mainly found through inspection...
[16 Jul 2019 12:43] MySQL Verification Team 
Hi Mr. Lee,

Thank you for your bug report.

If I understand you correctly, you have found only one more spot where the lock is not cleared.

Am I correct in this assumption ???
[17 Aug 2019 1:00] Bugs System 
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[22 Aug 2019 13:06] MySQL Verification Team 
Hi Mr. Lee,

Can you, please, answer our question .....
[5 Sep 2019 11:57] Jie Zhou 
https://bugs.mysql.com/bug.php?id=95181
[5 Sep 2019 12:50] MySQL Verification Team 
Hello Mr. Lee,

Seems that your bug report is a duplicate of this one:

https://bugs.mysql.com/bug.php?id=95181

Let me know if you agree with this opinion. Also, if you do not agree with it, then just answer to my original question about the list of locations where that lock has to be cleared.

Many thanks in advance.
[23 Sep 2019 1:00] Bugs System 
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[23 Sep 2019 12:27] MySQL Verification Team 
Hello Mr. Lee,

We are still waiting on your feedback.

Thanks in advance.
[24 Oct 2019 1:00] Bugs System 
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[24 Oct 2019 11:18] MySQL Verification Team 
Duplicate of:

https://bugs.mysql.com/bug.php?id=95181
[24 Oct 2019 22:39] Herman Lee 
Yes, it seems like this is a duplicate. Sorry for the late reply. It looks like all of the notification emails were forwarded to a separate folder due to an automated filter.