Bug #90902 | Select Query With Complex Joins Leaks File Handles | ||
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Submitted: | 17 May 2018 2:31 | Modified: | 25 Feb 2019 13:01 |
Reporter: | James Wilson | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Optimizer | Severity: | S2 (Serious) |
Version: | 5.7, 5.7.22 | OS: | Ubuntu (Ubuntu 16:04, Open Stack) |
Assigned to: | CPU Architecture: | x86 (2 CPUs, 16GB RAM) |
[17 May 2018 2:31]
James Wilson
[17 May 2018 3:37]
James Wilson
MySQL config file
Attachment: my.cnf (application/octet-stream, text), 1.60 KiB.
[17 May 2018 3:37]
James Wilson
Query that exhibits the failure
Attachment: Query.sql (application/octet-stream, text), 7.42 KiB.
[17 May 2018 3:40]
James Wilson
I have uploaded a file called mysql-bug-data-90902.zip to sftp.oracle.com. This file contains the data set that can be used to replicate the issue.
[17 May 2018 10:04]
MySQL Verification Team
Hello James, Thank you for the report. I didn't observe any crash etc in my 3 attempts on 5.7.22 but observed that deleted tmp files not cleaned up and thus prevented other operations once open files limit exhausted. Thanks, Umesh
[17 May 2018 11:51]
James Wilson
Hi Umesh, You won't see a "crash" until MySQL runs out of file handles. I have to run the query many times before it runs out. Also, when I say "crash", MySQL throws an error in the MySQL logs (error 24 from memory) then refuses to respond to requests to process queries.
[25 Feb 2019 13:01]
Jon Stephens
Documented fix in the MySQL 5.7.26 and 8.0.16 changelogs as follows: Some queries involving complex joins leaked file handles. Closed.