Disabling innodb_thread_concurrency might cause queries to hang

Bug #1168354 reported by Raghavendra D Prabhu on 2013-04-12
10
This bug affects 2 people
Affects Status Importance Assigned to Milestone
MySQL Server
Unknown
Unknown
Percona Server
Status tracked in 5.7
5.1
High
Unassigned
5.5
High
Unassigned
5.6
High
Unassigned
5.7
High
Unassigned

Bug Description

lp:702165 seems to be fixed in PS (there is no fix attached to issue though), however, http://bugs.mysql.com/bug.php?id=68876 seems to be reported again with a test case. So it would be better to reverify this again.

tags: added: innodb

Test case from the upstream bug report hangs perfectly on Debug build of Percona-Server-5.5.30-rel30.2.

This is what we have in PS 5.6.10:

[openxs@chief mysql-test]$ ./mtr bug68876
Logging: ./mtr bug68876
2013-05-15 13:04:58 0 [Warning] Changed limits: max_open_files: 1024 max_connections: 151 table_cache: 431
2013-05-15 13:04:58 1196 [Note] Plugin 'FEDERATED' is disabled.
2013-05-15 13:04:58 1196 [Note] Binlog end
2013-05-15 13:04:58 1196 [Note] Shutting down plugin 'CSV'
2013-05-15 13:04:58 1196 [Note] Shutting down plugin 'MyISAM'
MySQL Version 5.6.10
Checking supported features...
 - SSL connections supported
 - binaries are debug compiled
Collecting tests...
Removing old var directory...
Creating var directory '/home/openxs/bzr2/percona-5.6/Percona-Server/mysql-test/var'...
Installing system database...
Using server port 46495

==============================================================================

TEST RESULT TIME (ms) or COMMENT
--------------------------------------------------------------------------

worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
main.bug68876 [ fail ]
        Test ended at 2013-05-15 13:05:39

CURRENT_TEST: main.bug68876
mysqltest: In included file "./include/wait_condition.inc":
included from ./include/wait_condition.inc at line 60:
At line 60: Timeout in wait_condition.inc for $wait_condition

The result from queries just before the failure was:
< snip >
SET GLOBAL innodb_thread_concurrency = 1;
BEGIN;
SELECT * FROM t1 WHERE a = 1;
a b
1 1
BEGIN;
SELECT * FROM t1 WHERE a = 1;
a b
1 1
SET DEBUG_SYNC='innodb_row_update_for_mysql_begin SIGNAL inside_innodb WAIT_FOR go';
UPDATE t1 SET b = b + 1 WHERE a = 2;
SET DEBUG_SYNC='now WAIT_FOR inside_innodb';
SELECT * FROM t1 WHERE a = 3;
...

tags: added: upstream
summary: - Issue with innodb_thread_concurrency
+ Disabling innodb_thread_concurrency might cause queries to hang
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