MySQL DELETE语句HANG住问题解决纪实

时间:2020-12-05 21:47:11

1MySQL 简单的delete语句hang

同事说线上一个库执行简单的delete卡住了,我去check线上库的负载很低,show full processlist;也没有啥慢卡住或者锁的sql在执行,那问题在哪里呢?去查看错误日志,有如下信息

2017-03-14T01:32:22.628309Z 6553507 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:23.491555Z 6553508 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:24.718334Z 6553515 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:24.755244Z 6553516 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:25.816457Z 6553517 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:26.908096Z 6553519 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:28.078465Z 6553523 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:29.102774Z 6553527 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2017-03-14T01:32:30.205321Z 6553528 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

 

 

 

用more查看出现这个的最新时间是2016-05-03日,已经是很久以前的事情了

[root@prod_3_11 mysql]# more /usr/local/mysql/mysqld.log |grep 127.0.0.1 |more

2016-05-03T08:57:13.997474Z 1701 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T08:57:16.117305Z 1702 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T08:57:30.661653Z 1704 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T08:58:16.491907Z 1705 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T08:58:31.221777Z 1707 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T08:59:30.861211Z 1709 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

2016-05-03T09:00:12.617069Z 1710 [Note] Access denied for user 'root'@'127.0.0.1' (using password: NO)

 

 

 

2、问题分析

突然想到2016-05-03,刚在这太mysql库里面添加了zabbix监控,难道是zabbix的agent引起的问题?看到这个登陆失败,于是关闭zabbix的agent

[root@prod_3_11 mysql]# killallzabbix_agentd

[root@prod_3_11 mysql]#

 

在查看mysql的错误日志/usr/local/mysql/mysqld.log,没有新的Access deniedfor user 'root'@'127.0.0.1' (using password: NO)错误信息过来,而mysql库也稳定下来了,看来问题出在zabbix的监控访问上面。

 

去查看zabbix的agent'启动方式,找到zabbix配置文件zabbix_agentd.conf

[root@prod_3_11 ~]# ps -eaf|grep zabbix

zabbix   27118     1  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf

zabbix   27119 27118  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd: collector [idle 1 sec]         

zabbix   27120 27118  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd: listener #1 [waiting for connection]

zabbix   27121 27118  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd: listener #2 [waiting for connection]

zabbix   27122 27118  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection]

zabbix   27123 27118  0 13:54 ?        00:00:00 /usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec]  

root     27590 15250  0 13:58 pts/4    00:00:00 grep zabbix

[root@prod_3_11 ~]#

 

 

 

再查看配置文件/etc/zabbix/zabbix_agentd.conf,进入到最文件最末端,找到关于mysql的配置

UserParameter=mysql.version,mysql -V

UserParameter=mysql.status[*],/usr/local/zabbix/chk_mysql_1.sh $1 $2

UserParameter=mysql.ping,nmap 192.168.3.11 -p 3317|grep open |wc -l

UserParameter=mongodmonitor,/usr/local/zabbix/mongodmonitor.sh "$1"

 

 

 

关于mysql的有2行记录,执行下这2行记录,看是否能顺利执行

1)第一行是mysql.pingok,可以执行

         [root@prod_3_11 ~]# nmap 192.168.3.11 -p 3317|grep open |wc -l

         1

         [root@prod_3_11 ~]#

 

2)第二行是执行一个脚本

         [root@prod_3_11 ~]# sh /usr/local/zabbix/chk_mysql_1.sh

         Please input one arguement:

         Usage:/usr/local/zabbix/chk_mysql_1.sh(Uptime|Com_update|Slow_queries|Com_select|Com_rollback|Questions)

         [root@prod_3_11 ~]# sh /usr/local/zabbix/chk_mysql_1.sh Com_update

         mysqladmin: connect to server at '127.0.0.1' failed

         error: 'Access denied for user 'root'@'127.0.0.1' (using password: NO)'

 

         [root@prod_3_11 ~]#

 

         看到了,执行报错“'Accessdenied for user 'root'@'127.0.0.1' (using password: NO)'”,这个错误也是在mysql的后台错误日志频繁出现的,终于找到了,那么这里就要去看下这个脚本/usr/local/zabbix/chk_mysql_1.sh,为啥会频繁报错。

 

3、问题解决  

看到脚本里面的密码好像是旧的,需要修复脚本/usr/local/zabbix/chk_mysql_1.sh,更新里面的用户名密码。

 

然后再启动zabbix的客户端引擎。

/usr/local/zabbix/sbin/zabbix_agentd -c/usr/local/zabbix/conf/zabbix_agentd.conf

 

回过头,查看mysql窗口等待的delete语句,已经消失了,查看数据,已经被删除了。