Bug #55001 Change in behavior: thread_concurrency (docs, example files)
Submitted: 5 Jul 2010 13:17 Modified: 20 Nov 2010 18:07
Reporter: Andrii Nikitin Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:5.5.4-m3 OS:Any (except Solaris)
Assigned to: Magne Mæhre CPU Architecture:Any
Triage: Triaged: D3 (Medium)

[5 Jul 2010 13:17] Andrii Nikitin
Description:
(According to manual "thread_concurrency" variable is usable only for Solaris OS)

In 5.1 mysqld will start properly if thread_concurrency is defined in configuration file (just will ignore it).

In 5.5 (non-Solaris), mysqld will show error like:

[ERROR] ./bin/mysqld: unknown variable 'thread_concurrency=8'

How to repeat:
1. Copy example file:
cp /usr/local/mysql/support-files/my-huge.cnf /etc/mysql/my.cnf

2. Start 5.5.4 => see error in log file

Suggested fix:
Make behavior identical to 5.1

- OR -

1. Document incompatible change
2. Fix example files:
a@u:~/Downloads$ grep thread_concurrency 5.5.4/support-files/*

my-huge.cnf
my-innodb-heavy-4G.cnf
my-large.cnf
[5 Jul 2010 15:28] Davi Arnaut
On 5.5, the variable is only available when the underlying function actually exists -- Solaris.
[13 Aug 2010 14:37] Konstantin Osipov
The variable has no effect, even on Solaris, neither in 5.1 nor in 5.5.
[13 Aug 2010 14:41] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/115695

3108 Konstantin Osipov	2010-08-13
      A draft patch for Bug#55001 "Change in behavior:
       thread_concurrency (docs, example files)"
      Put the variable back, on all platforms.
      The variable is unused and has no effect, already in 5.1, but
      will be removed along with others in scope of deprecation process.
[16 Aug 2010 12:27] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/115779

3108 Magne Mahre	2010-08-16
      Bug#55001 Change in behavior: thread_concurrency (docs, 
                example files)
      
      The system variable 'thread_concurrency' has been
      (re-)enabled on all platforms, to prevent startup
      errors.
      
      'thread_concurrency' is unused and has no effect,
      on no platforms, in MySQL 5.1 and later versions.  It 
      will be deprecated and removed in context of 
      worklog WL#5265
     @ mysql-test/include/have_thread_concurrency.inc
        include/have_thread_concurrency.inc was only needed
        to support platforms that didn't have the
        thread_concurrency variable available.  Since the
        variable is now available on all platforms, the file
        is removed.
[16 Aug 2010 12:59] Jon Olav Hauglid
Patch approved with minor comments discussed on IRC.
[16 Aug 2010 13:05] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/115788

3108 Magne Mahre	2010-08-16
      Bug#55001 Change in behavior: thread_concurrency (docs, 
                example files)
      
      The system variable 'thread_concurrency' has been
      (re-)enabled on all platforms, to prevent startup
      errors.
      
      'thread_concurrency' is unused and has no effect,
      on any platform, in MySQL 5.1 and later versions.  It 
      will be deprecated, and removed, in context of 
      worklog WL#5265
     @ mysql-test/include/have_thread_concurrency.inc
        include/have_thread_concurrency.inc was only needed
        to support platforms that didn't have the
        thread_concurrency variable available.  Since the
        variable is now available on all platforms, the file
        is removed.
[25 Aug 2010 9:24] Bugs System
Pushed into mysql-5.5 5.5.6-m3 (revid:alik@ibmvm-20100825092002-2yvkb3iwu43ycpnm) (version source revid:alik@ibmvm-20100825092002-2yvkb3iwu43ycpnm) (merge vers: 5.5.6-m3) (pib:20)
[26 Aug 2010 2:18] Paul Dubois
Noted in 5.5.6 changelog.

The thread_concurrency system variable was unavailable on Solaris.

Setting report to Need Merge pending push to 5.6.x.
[30 Aug 2010 8:32] Bugs System
Pushed into mysql-trunk 5.6.1-m4 (revid:alik@sun.com-20100830082732-n2eyijnv86exc5ci) (version source revid:alik@sun.com-20100830082732-n2eyijnv86exc5ci) (merge vers: 5.6.1-m4) (pib:21)
[30 Aug 2010 8:35] Bugs System
Pushed into mysql-next-mr (revid:alik@sun.com-20100830082745-n6sh01wlwh3itasv) (version source revid:alik@sun.com-20100830082745-n6sh01wlwh3itasv) (pib:21)
[30 Aug 2010 18:27] Paul Dubois
Noted in 5.6.1 changelog.
[31 Aug 2010 1:00] Paul Dubois
Correction to changelog entry:

The thread_concurrency system variable was unavailable on non-Solaris systems.
[13 Nov 2010 16:05] Bugs System
Pushed into mysql-trunk 5.6.99-m5 (revid:alexander.nozdrin@oracle.com-20101113155825-czmva9kg4n31anmu) (version source revid:vasil.dimov@oracle.com-20100629074804-359l9m9gniauxr94) (merge vers: 5.6.99-m4) (pib:21)
[13 Nov 2010 16:30] Bugs System
Pushed into mysql-next-mr (revid:alexander.nozdrin@oracle.com-20101113160336-atmtmfb3mzm4pz4i) (version source revid:jimmy.yang@oracle.com-20100804103744-vbpeghipkz6pyc9z) (pib:21)