| Bug #34409 | LOCK_plugin contention via ha_release_temporary_latches/plugin_foreach | ||
|---|---|---|---|
| Submitted: | 8 Feb 2008 12:33 | Modified: | 28 Jul 2008 17:11 |
| Reporter: | Sergei Golubchik | ||
| Status: | Closed | ||
| Category: | Server | Severity: | S2 (Serious) |
| Version: | 5.1 | OS: | Any |
| Assigned to: | Sergei Golubchik | Target Version: | 5.1+ |
| Triage: | D2 (Serious) / R2 (Low) / E2 (Low) | ||
[8 Feb 2008 12:33]
Sergei Golubchik
[21 Feb 2008 3:23]
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/42727 ChangeSet@1.2525, 2008-02-20 18:23:08-08:00, acurtis@xiphis.org +6 -0 Bug#34409 "LOCK_plugin contention via... plugin_foreach()" First commit draft for comments/review.
[3 Jun 2008 18:55]
Heikki Tuuri
Since I presume only InnoDB uses this call, we could remove the LOCK_plugin mutex call
altogether?
handler.cc in an oldish 5.1:
"
static my_bool release_temporary_latches(THD *thd, plugin_ref plugin,
void *unused)
{
handlerton *hton= plugin_data(plugin, handlerton *);
if (hton->state == SHOW_OPTION_YES && hton->release_temporary_latches)
hton->release_temporary_latches(hton, thd);
return FALSE;
}
int ha_release_temporary_latches(THD *thd)
{
plugin_foreach(thd, release_temporary_latches, MYSQL_STORAGE_ENGINE_PLUGIN,
NULL);
return 0;
}
"
[15 Jul 2008 5:33]
Mark Callaghan
When does this get into a RC? It doesn't appear to be in 5.1.26.
[15 Jul 2008 9:37]
Sergei Golubchik
It doesn't, because it isn't fixed yet, there's no patch attached (no approved patch at least), the bug isn't closed yet. But we plan to fix it in the next 5.1 release.
[18 Jul 2008 15:16]
Mark Callaghan
I ran a suite of benchmarks (sysbench oltp, sysbench oltp readonly, concurrent inserts, concurrent joins, tpc-b, wisconsin). Performance for 5.1.25 with InnoDB was similar to the faster 5.0 versions for all of the tests except tpc-b. In that case it was ~25% slower. I think this is the cause. I hope 5.1 doesn't go GA without a fix for this.
[18 Jul 2008 18:23]
Mark Callaghan
I will update with results after removing that lock so I can stop speculating. Thanks for the pointer to the other problem.
[18 Jul 2008 18:27]
Mark Callaghan
The referenced bug is http://bugs.mysql.com/bug.php?id=38185
[21 Jul 2008 11:13]
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/50100 2671 Sergei Golubchik 2008-07-21 Bug#34409 LOCK_plugin contention via ha_release_temporary_latches/plugin_foreach use thread-local data structures in ha_release_temporary_latches()
[21 Jul 2008 11:43]
Konstantin Osipov
Approved on IRC with one review comment.
[21 Jul 2008 12:01]
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/50106 2671 Sergei Golubchik 2008-07-21 Bug#34409 LOCK_plugin contention via ha_release_temporary_latches/plugin_foreach use thread-local data structures in ha_release_temporary_latches()
[22 Jul 2008 20:40]
Bugs System
Pushed into 5.1.28
[25 Jul 2008 15:24]
Paul DuBois
How can I describe this problem so that its impact is apparent to changelog readers? Plugins has excessive lock contention that affected performance?
[25 Jul 2008 17:56]
Sergei Golubchik
Fixed a slowdown significant when many queries executing SELECTs that return many rows from InnoDB tables were running concurrently.
[25 Jul 2008 18:26]
Paul DuBois
Noted in 5.1.28 changelog. A significant slowdown occurred when many SELECT statements that return many rows from InnoDB tables were running concurrently. Setting report to Patch Queued pending push of fix into 6.0.x.
[28 Jul 2008 16:02]
Georgi Kodinov
Pushed into 6.0.7-alpha
[28 Jul 2008 16:45]
Bugs System
Pushed into 6.0.7-alpha (revid:alik@mysql.com-20080725172155-fnc73o50e4tgl23k) (version source revid:alik@mysql.com-20080725172155-fnc73o50e4tgl23k) (pib:3)
[28 Jul 2008 17:11]
Paul DuBois
Noted in 6.0.7 changelog.
[28 Jul 2008 18:44]
Bugs System
Pushed into 5.1.28 (revid:davi.arnaut@sun.com-20080722182431-0i2f1yc4uocime9q) (version source revid:davi.arnaut@sun.com-20080722182431-0i2f1yc4uocime9q) (pib:3)
[14 Sep 2008 3:31]
Bugs System
Pushed into 6.0.7-alpha (revid:serg@mysql.com-20080721100122-bgt8gldl1hqoxafc) (version source revid:vvaintroub@mysql.com-20080804094710-jb2qpqxpf2ir2gf3) (pib:3)
