Bug #29393 | MySQL Server is locked because of a "flush query cache" on heavy load | ||
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Submitted: | 27 Jun 2007 16:07 | Modified: | 17 Jul 2007 1:18 |
Reporter: | Frédéric Dhieux | Email Updates: | |
Status: | Duplicate | Impact on me: | |
Category: | MySQL Server: Locking | Severity: | S1 (Critical) |
Version: | 5.0.41 | OS: | Linux (X86_64 binary) |
Assigned to: | CPU Architecture: | Any |
[27 Jun 2007 16:07]
Frédéric Dhieux
[27 Jun 2007 18:55]
Sveta Smirnova
Thank you for the report. Please provide output of statements SHOW GLOBAL VARIABLES LIKE 'query_cache%'; and SHOW GLOBAL STATUS LIKE 'Qcache%';
[28 Jun 2007 10:13]
Frédéric Dhieux
mysql1> SHOW GLOBAL VARIABLES LIKE 'query_cache%'; +------------------------------+-----------+ | Variable_name | Value | +------------------------------+-----------+ | query_cache_limit | 2097152 | | query_cache_min_res_unit | 4096 | | query_cache_size | 268435456 | | query_cache_type | ON | | query_cache_wlock_invalidate | OFF | +------------------------------+-----------+ 5 rows in set (0.00 sec) mysql1> SHOW GLOBAL STATUS LIKE 'Qcache%'; +-------------------------+-----------+ | Variable_name | Value | +-------------------------+-----------+ | Qcache_free_blocks | 39679 | | Qcache_free_memory | 132175992 | | Qcache_hits | 8932226 | | Qcache_inserts | 3314332 | | Qcache_lowmem_prunes | 772643 | | Qcache_not_cached | 1585865 | | Qcache_queries_in_cache | 90620 | | Qcache_total_blocks | 222362 | +-------------------------+-----------+ 8 rows in set (0.00 sec) I can provide some graphs between 2007-06-26 06:30 and 2007-06-27 21:30 : http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_free_blocks.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_free_memory.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_hits.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_inserts.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_lowmem_prun.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_not_cached.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_q_incache.png http://sly.peer.fr/mysql-bug/graphs/mysql1/day-myext_Qcache_total_blocks.png Crash at 17:14 the 27th FLUSH QUERY CACHE query at : 070627 9:18:48 070627 9:33:14 070627 9:55:46 070627 11:06:01 070627 14:27:55 070627 14:36:26 070627 14:47:14 070627 14:53:36 070627 15:51:26 070627 15:56:59 070627 16:04:40 070627 16:09:48 070627 16:15:06 070627 16:24:23 070627 16:34:26 070627 16:39:27 070627 17:14:41 -> Lock Heavy load begins at about 17:00.
[17 Jul 2007 1:18]
Adam Dixon
This bug looks to be a duplicate; http://bugs.mysql.com/bug.php?id=21074