MySQL更新在“结束”状态上花费很长时间

Question

I'm having issues with this update query. I don't understand why would the "end" state take so long.

The weird part is that it happens only if I haven't updated the table for a while but after I do, the update queries are super fast.

I wouldn't care if one update query takes a long time to complete but this query halts every other queries (select/insert/update..) in the server so all of them have to wait until this one is finished.

I've read a lot through other discussions but all of them were about the "query end" not the "end" state.

This is my latest query that took over 70 seconds:

UPDATE optimizer_disabled_domains 
SET dateChanged = NOW( ) ,
 bgProcessID =18,
 profile =  '1. Default',
 creativeIDs =  '',
 excludeCreativeIDs =  '',
 emailGroupIDs =  '1',
 emailDomains =  '',
 status =1 
WHERE id =237

Profiling stats:

 starting => 0.000053
 checking permissions => 0.000010
 Opening tables => 0.000029
 System lock => 0.000010
 init => 0.000042
 Updating => 0.000106
 end => 0.000009
 Waiting for query cache lock => 0.000007
 *** end => 69.276521 ***
 query end => 0.000203
 closing tables => 0.000098
 freeing items => 0.000082
 logging slow query => 0.000035
 logging slow query => 0.000063
 cleaning up => 0.000033

Table structure:

 CREATE TABLE IF NOT EXISTS `optimizer_disabled_domains` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `dateCreated` datetime NOT NULL,
   `dateChanged` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `bgProcessID` int(11) NOT NULL,
   `profile` varchar(100) NOT NULL DEFAULT '',
   `creativeIDs` varchar(255) NOT NULL DEFAULT '',
   `excludeCreativeIDs` varchar(255) NOT NULL DEFAULT '',
   `emailGroupIDs` varchar(30) NOT NULL DEFAULT '',
   `emailDomains` varchar(1000) NOT NULL DEFAULT '',
   `status` tinyint(1) NOT NULL DEFAULT '1',
   PRIMARY KEY (`id`),
   KEY `status` (`status`,`bgProcessID`,`profile`,`creativeIDs`,`excludeCreativeIDs`,`emailDomains`(255),`emailGroupIDs`)
) ENGINE=InnoDB

Answer 1

Might be a DNS problem.Add this line in your mysql config and restart

skip-name-resolve

Also check query cache,if its too large,you may see lock contention issues with a very large cache. Link

SHOW VARIABLES LIKE 'query_cache_size';