Bug #96879 MyISAM I/O contention
Submitted: 15 Sep 2019 3:51 Modified: 15 Sep 2019 5:32
Reporter: Prudhvi Mutluri Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: MyISAM storage engine Severity:S1 (Critical)
Version:5.6.36 OS:CentOS (CentOS Linux release 7.3.1611 (Core))
Assigned to: CPU Architecture:x86 ( 3.10.0-514.16.1.el7.x86_64)

[15 Sep 2019 3:51] Prudhvi Mutluri
Description:
on out production mysql database we saw spike in slow queries which caused the application health checks fail.

from the monitoring tools we figured out there is spike in MyISAM wait/io/dfile/write.

Innodb engine stopped responding 

client connections jumped from 300 to 2000.

client thread activity spiked.

How to repeat:

more slow query logs slows down myisam engine

Suggested fix:
need help in this issue?
[15 Sep 2019 5:32] Shane Bester
We're sorry, but the bug system is not the appropriate forum for asking help on using MySQL products. Your problem is not the result of a bug.

For details on getting support for MySQL products see http://www.mysql.com/support/
You can also check our forums (free) at http://forums.mysql.com/

Thank you for your interest in MySQL.